"Marbles of the Belly": The Pediatric Spectrum of Cystic Abdominal

“Marbles of the belly”
The Pediatric Spectrum of Cystic Abdominal Lesions
Drs. Katie Lopez, Maria D’almeida and Ricardo Restrepo
Take a tour through the different
sections of the abdomen, to see
the common and not so common
pediatric cystic lesions which arise
from various organs.
Click on the icon to the right to go
to each specific section. A main
menu icon on each slide (in the
top right corner) will take you
back to this page.
Urinary Tract
Pancreas,
Hepatobiliary
Gynecologic
Non-organ
based cysts
Bladder
6.1cm
Clinical history:
• 10 year old girl with lower abdominal pain.
• Differential diagnosis?
Bladder
•In both adnexa, are enlarged multi-cystic masses with enhanced
through transmission. No normal ovarian tissue was discernible.
•Differential diagnosis includes polycystic ovaries, ovarian
hyperstimulation syndrome or cystic ovarian tumor.
Bilateral serous
cystadenomas
Discussion of the differential diagnosis:
•In polycystic ovaries (PCOS), the ovaries are enlarged with classically small
follicles and cysts (<10mm). Our patient did not have the classic triad of obesity,
hirsutism and menstrual abnormalities commonly seen in PCOS.
•In ovarian hyperstimulation syndrome (OHSS), the ovaries would have the same
appearance, however ascites is commonly seen. Classic OHSS is seen in women of
child-bearing age on ovarian stimulating medication (Perganol).
•Causes of polycystic ovaries in kids is from unopposed estrogen stimulation, such
as genetic deficiencies in certain enzymes, particularly 21-hydroxylase (congenital
adrenal hyperplasia). Bilateral ovarian cysts have been observed in older girls with
longstanding, untreated hypothyroidism.
Bilateral serous
cystadenomas
Discussion:
•Ovarian neoplasms are not common in children. They are divided into origin of
their cellular components: germ cell, sex cord stromal, and surface epithelial.
•Only 20% of pediatric ovarian tumors are epithelial, with 80% of those being
cystadenomas. Most common tumor is the germ cell (60%) with most of those being
teratomas.
•Cystadenomas are benign tumors, uncommon before puberty and are usually
unilateral. They contain serous or mucinous material.
•Classic finding on ultrasound is that of a multiseptated cystic mass.
•Our patient remained asymptomatic, however since there was a familial history of
ovarian teratoma with torsion, elective laparoscopy was performed. The cysts were
enucleated from the ovaries and normal ovarian tissue was salvaged.
This is a different patient with a serous cystadenoma. The
patient is a 16 year old female with acute abdominal pain
and vomiting. The ultrasound was notable for a large
intra-abdominal, nonvascular cystic mass of uncertain
etiology. A normal right ovary was seen, but not a left
ovary. A CT scan was performed.
Scout film from the
CT scan revealed an
abnormal density
along the right lower
abdomen and pelvis
with mass-effect on
adjacent bowel.
•CT reveals a large cystic mass
with a tubular stalk that descends
into the pelvis.
•The mass appeared pelvic in
origin therefore an ovarian cystic
lesion was of concern.
Serous cystadenoma with torsion
• There was a radiographic and clinical concern for
torsion, therefore the patient was taken to the OR.
The mass arose from the left ovary and had torsed
the ovary and fallopian tube by 720º and had
flipped up into the abdomen. The left ovary was
not salvageable.
• Important teaching point = if you think there could
be ovarian torsion, then raise the possibility!
Clinical history:
•9 year old girl with 2 day history of intermittent abdominal
pain with vomiting.
•Diagnosis?
Findings:
•Ultrasound demonstrates a large, avascular cystic mass in the pelvis, slightly right
of midline. The mass is adjacent to, but separate from the ovaries. The mass has a
well defined wall and contains a few septations or excresences off the wall.
•Differential diagnosis: cystic ovarian mass versus a developmental cyst.
CT was performed to better
evaluate the mass. What is your
diagnosis now?
Dermoid (cystic teratoma)
CT demonstrates a predominantly cystic mass in the pelvis
which contains a focus of fat and calcification.
Dermoid Cyst (Mature cystic teratoma)
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Because of the clinical symptoms, associated ovarian torsion could not
be excluded. At surgery, the mass had caused torsion, however the
ovary was salvageable.
60% of ovarian tumors in kids are germ cell in origin, of which 70%
are teratomas.
The terms “dermoid” and “teratoma” are used interchangeably,
however precise definition of dermoid is that it contains two cell
layers, while teratoma contains all three (endo-, meso- and ectoderm).
Almost all are benign and 25% are bilateral.
US – 2/3rd are complex cystic lesions commonly with echogenic debris
or shadowing portions which obscure deeper areas of the mass (“tip of
the iceberg” sign). 1/3rd are either predominantly solid or cystic.
CT is good for showing fatty and calcific components.
•Clinical history: 16 year old female who presented with 1 week of abdominal
pain, no vomiting or fever. The C-reactive protein and white blood cells were
elevated, ß-HCG was negative. An ultrasound was ordered.
•Findings: A small cyst in the pelvis and enlarged right ovary. Since the labs
were notable for infection, a contrasted CT scan was performed.
•CT scan demonstrated the
same cystic lesion in the pelvis
(arrow), however also showed
significant inflammatory
changes in the region of the
right hemi-pelvis, and
enlargement of the right ovary
compared to the left. The cyst
was thought to represent a
para-ovarian cyst on the prior
ultrasound.
•Considerations for the
inflammation in the right
hemi-pelvis included: pelvic
inflammatory disease or
possibly ovarian torsion.
Cyst of Morgagni with
tubal torsion
• Since the patient had an acute abdomen, she was
taken to the OR.
• A 3 cm cyst was seen at the tip of the right
fallopian tube resulting in tubal torsion. The
ovary however was not torsed.
• Cyst of Morgagni is a type of para-ovarian cyst.
If the cyst is attached to the fringes of the fallopian
tubes, they are referred to as cysts of Morgagni, or
Hydatids of Morgagni.
• Even though the cyst was very small, it resulted in
torsion.
Clinical history:
BL
BL
•Newborn female
undergoing an out-patient
renal ultrasound to
follow-up a prenatal
diagnosis of
hydronephrosis.
•Upon imaging of the
bladder, we noted an
adjacent large cystic
structure in the pelvis
with a fluid-debris level.
BL
Differential diagnosis of a
complex cystic lesion in the
BL
pelvis in a neonate:
• hemorrhagic ovarian or
developmental/duplication
cyst
• dilated fluid filled vagina or
uterus seen in hydrocolpos or
obstructed uterine horn in a
didelphic system.
We verified the presence of a
normal uterus (seen at left).
The location and
characteristics were
compatible with a
hemorrhagic neonatal
ovarian cyst.
Neonatal ovarian cyst
BL
BL
• Not uncommonly seen and perhaps due to
increased sensitivity to maternal hormones.
• The larger cysts are at increased risk for ovarian
torsion. It is reported that fluid debris levels and
low level echoes suggest torsion.
• These can be followed conservatively if smaller,
but may need surgical intervention if large.
Clinical history:
•17 year old sexually active
female with 5 day history of
abdominal pain and fever. White
blood cell count is elevated.
•Diagnosis?
BL
Right
BL
Left
bladder
Clinical history:
•The ultrasound demonstrated
dilated, cystic tubular structures,
with some internal debris, on both
sides of the pelvis. No normal
ovarian tissue was seen.
Right
•The differential diagnosis
includes hydrosalpinx,
pyosalpinx, or tubo-ovarian
abscesses (TOA).
•Patient also had a CT scan for
further evaluation.
Left
•The CT scan also demonstrated dilated, cystic tubular structures with
enhancing walls in the region of both adnexa with continued differential of
hydrosalpinx, pyosalpinx or bilateral TOAs.
•Pyosalpinx or TOA was of more concern due to fever and abnormal labs.
•As the patient had persistent abdominal pain and fever refractory to medical
management, she was taken to the OR for exploration.
Bilateral Tubo-ovarian abscesses
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At surgery, both fallopian tubes were aspirated with the removal of
copious amounts of frank pus. There were innumerable adhesions in
the pelvis as well. This suggests pelvic inflammatory disease resulting
in tubo-ovarian abscess (TOA).
TOAs result from pelvic inflammatory disease with extension of
infection into the tubes AND ovaries.
Tends to be bilateral.
US is unreliable in distinguishing pyosalpinx from hydrosalpinx, as
echoless fluid can be infected and echogenic fluid is not always
infected.
Most common US finding in TOA, is partial or complete replacement
of the normal ovarian tissue by a heterogeneous mass or a hypoechoic
area with contained debris.
Clinical history:
•37 weeker born with
hydrops and common
urogenital sinus.
•Prenatal ultrasound was
notable for bilateral
hydronephrosis and
distended bladder.
•This newborn underwent
ultrasound of the kidneys
and bladder to follow-up the
prenatal findings.
•Can you see the
abnormality on this plain
film?
Did you notice the
abnormal density in the
lower abdomen/pelvis
with displacement of
bowel loops?
•The ultrasound shows a cystic mass posterior to the decompressed bladder which contains a foley
balloon (arrow). There is a large amount of debris within the mass.
•Differential diagnosis includes: hemorrhagic neonatal ovarian or developmental/duplication cyst.
•The key point in these cases is to always look for the uterus, so you don’t get fooled into calling an
ovarian cyst when the other possibility is an obstructed vagina or uterus in either
hydrocolpos/hematocolpos or obstructed uterine horn in a didelphic system.
Further evaluation demonstrated the large cystic mass to
represent an obstructed, debris filled vagina, which you can
see attaches to a mildly distended endometrial canal of the
uterus (arrow).
MRI was performed to better delineate the anatomy. T2 sagittal images
demonstrate a markedly dilated vagina which is blind ending in the pelvis. This
represents hydrocolpos/hematocolpos. The make-up of the fluid in the vagina
determines whether this is hydro- (simple fluid) or hematocolpos (blood).
Hydrocolpos/Hematocolpos
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A congenital obstruction - either persistent urogenital sinus or cloacal
malformation in the neonate. If diagnosed in the older child/adolescent
then secondary to imperforate hymen, segmental vaginal atresia or
transverse vaginal septum.
Rare to present in the newborn period, more commonly diagnosed
during adolescence.
If uterus is distended as well, then called hydro-/hematometrocolpos.
Echogenic debris is mucus secretions secondary to stimulation by
maternal estrogens in utero. In older patients, the debris represents
blood products and sloughed endometrial lining.
Key point! – urinary and gynecologic malformations are associated,
therefore always inspect the other system when you find an
abnormality in one.
Companion case - Clinical history:
16 year old female with spina bifida, augmented neurogenic bladder and
ventriculoperitoneal shunt, presents with increasing abdominal size.
Patient has never had a normal menstruation. She had occasional
irregular periods with scant blood only.
BL
Findings:
There is a large echogenic mass in the abdomen, extending from the epigastrum into the
pelvis. The mass has a thick wall and what appears to be layering debris (arrow). The
bladder (BL) is separate from the mass. The mass has a bilobed appearance with a smaller
portion of the mass in the epigastrum which has a connection (thin arrow) to the larger
mass. Doppler imaging revealed no hypervascularity. Diagnosis?
•The findings, along with the clinical history, are consistent with hematometrocolpos.
•MRI was performed. T2 weighted oblique coronal and sagittal images are consistent with this
diagnosis. The vagina is markedly distended with a rounded inferior aspect. At surgery the patient
was noted to have a transverse vaginal septum. The smaller uterus has a fluid-debris level of
differing blood products.
This is a recent companion case of hematometrocolpos. This 15 year old
girl has never had a menstrual period and now presents to the emergency
department for worsening pelvic pain. The ultrasound findings and
clinical history are classic.
Clinical history:
This is a 13 year old female who
presented with acute urinary
retention. Prior history includes
normal menses. A renal
ultrasound was initially performed
(not shown), which noted a solitary
large left kidney and this large
cystic mass for which MRI was
performed for further evaluation.
The bladder was seen separately.
Thank you to Dr. Luisa Cervantes, from Miami Children’s
Hospital, for this case.
bladder
sag
coronal
The sagittal T2 demonstrates a large cystic mass which extends deep into the pelvis with a
blunted inferior end. The coronal view shows that the cystic mass communicates with the right
horn of a didelphic uterus (arrow).
•Axial images demonstrate the didelphic
uterus and the connection of the mass with the
right sided horn (arrow). Also note on the
image to the lower left, there is a compressed
structure directly to the left of the cystic mass
(arrow head). This has a very dark signal
intensity outer lining with bright internal
signal. This represents the vagina connected
to the left sided horn.
•Therefore this is a didelphic uterus with a
unilateral hydrocolpos.
Uterus didelphys with unilateral
hydrocolpos
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This is a total failure of müllerian
duct fusion. Complete duplication
involves 2 vaginas, 2 cervices and 2
uterine horns.
May be associated with renal
agenesis. Our patient did have an
absent right kidney.
Hydrocolpos was due to a transverse
vaginal septum.
Right lower
quadrant
Clinical history:
•4 month old male with a palpable right inguinal mass.
•Diagnostic considerations include patent processus vaginalis,
inguinal hernia and spermatic cord hydrocele.
Diagnosis: Spermatic cord hydrocele
•This is a cystic mass in the inguinal canal with blunted proximal and distal ends.
The distal end is near the superior scrotum and does not communicate with the
scrotal cavity. The proximal end is also blunted and does not communicate with
the peritoneal cavity. Valsalva manuever does not change the appearance of the
mass. A single septation inferiorly is seen.
Spermatic cord hydrocele
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Uncommon congenital anomaly.
Results from abnormal closure of the processus vaginalis.
Presentation is usually as firm groin swelling.
Ultrasound appearance classically shows an anechoic
lesion in the inguinal canal which does not communicate
with either the peritoneal or scrotal cavities. Septations
can be seen.
• Must distinguish from inguinal hernia. There should be
no bowel within the canal and no opening of the internal
inguinal ring suggesting communication with the
peritoneum.
Different patient:
•4 year old with persistent
right inguinal mass, that did
not change with valsalva or
communicate with the
scrotal or peritoneal
cavities.
•Again note the blunted
proximal and distal ends,
as seen in our last case.
This spermatic cord cyst
is more simple in
appearance.
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Pancreas and Hepatobiliary,
press the spacebar or enter
•7 year old boy who was in a scooter accident in which
the handlebars hit the child in the abdomen.
•What is the diagnosis and complications?
Pancreatic laceration
•Did you see the linear area of low density near the
pancreatic neck and small peripancreatic fluid?
•This represents a pancreatic laceration.
•A common presentation of this injury, just like our
child, involves the child falling onto handlebars of a
bicycle.
•If there is a ductal injury, then
complications are worse and include:
recurrent pancreatitis, pseudocyst,
pseudoaneurysm, fistula and abscess
Same case.
Our child had increasing
abdominal pain, so a repeat
CT scan was performed.
Do you see the abnormality
on the scout film?
There is mass-effect on
the stomach and
nasogastric tube,
resulting in deviation of
these structures to the
right.
Diagnosis?
•Axial images reveal a fluid collection in
the left upper quadrant. On the 1st image,
you could be fooled into thinking this was
the stomach, however note the position of
the NG tube, which does not go through the
fluid collection.
•The stomach and NG tube are compressed
by the cystic lesion.
•Where does it arise from? Note the close
apposition of the lesion with the pancreas.
Pancreatic pseudocyst
• Collection of pancreatic fluid encapsulated by fibrous
tissue.
• Requires >4 weeks to form and matures in 6-8 weeks.
• Usually is in the region of the pancreas, however can be in
the mediastinum or anywhere in the abdomen.
• Most resolve spontaneously.
• Well evaluated with US or CT.
• Indications for drainage: pain, suspected infection,
persistence of >5cm in size, increasing size, biliary/GI
obstruction.
Clinical history:
•12 year old female with blunt
abdominal trauma.
•Diagnosis?
A post-traumatic hematoma, right?
Not necessarily! Let’s look at the
images carefully.
•On this first image, there is a heterogeneous mass
with areas of low density (possibly fluid) and areas
of higher density (blood or solid material). You can
see the splenic vein (arrow). Note that the mass is
adjacent to the splenic vein, in the expected location
of where a normal pancreas should be.
•On this image, you can see a head and uncinate
process of the pancreas. Where is the body?
Also, note that the head of the pancreas makes a
“claw” sign (arrow) with the mass (the pancreas
wraps around a portion of the mass).
• With the history of blunt abdominal trauma, duodenal
hematoma should always be considered. This image
shows that the horizontal portion of the duodenum is
adjacent to the mass. Therefore, could this be a duodenal
hematoma?
•Since there was a history of trauma, we could not exclude
that this was a duodenal or mesenteric hemorrhage,
however with it’s mass-like appearance, we recommended
a follow up to insure resolution.
•The lesion did not resolve or change on a follow-up US,
therefore the patient was taken to the OR for exploration.
Papillary cystic tumor of the
Pancreas
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Not all trauma is bad. Because of the blunt trauma, we were able to
identify the tumor in this patient who was previously asymptomatic.
Pancreatic tumors are very rare in childhood.
Tumors may arise from the islet cells (insulinoma, gastrinoma),
exocrine tissue (cystadenoma, adenocarcinoma) or acinar cells
(pancreaticoblastoma).
Our patient’s tumor is a rare, low grade malignant tumor.
Commonly described as a well-encapsulated mass with considerable
hemorrhage and cystic degeneration.
Most frequently in the tail of the pancreas.
Prognosis is excellent after excision. Only 4 % present with
metastases.
•Clinical History: Full-term 6
month old female presenting with
jaundice and increasing abdominal
distention for 1 month
•Labs:elevated direct and indirect
bilirubin, ALT/AST, alkaline
phosphatase, WBC count
Differential Diagnosis?
• As this appears to involve the biliary tree,
there really is no differential, likely a
choledochal cyst.
• What test would you do next and why?
The next test was a nuclear medicine biliary scintigraphy. This test will prove if the cystic
structure connects with the biliary tree as it fills with radiotracer. Our study showed no excretion
by the liver due to severe dysfunction. Now what study would you do?
•Our patient was taken to
the OR for an
intraoperative
cholangiogram.
•The choledochal cyst was
percutaneously studied
and showed no excretion
from the cyst into the
duodenum, therefore it
was obstructed.
•The patient underwent
cyst removal and Roux-nY hepaticojejunostomy
Choledochal cyst
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Definition: refers to dilatation of the common bile duct which can be
either fusiform or saccular.
Classification scheme - most commonly used is the Todani et al. –
with 5 types.
80-90% are the Type I – dilatation of the common bile duct (CBD)
over a variable length (our patient had this type).
Pathogenesis - current theory is anomalous insertion of the pancreatic
duct into the CBD with reflux of pancreatic enzymes resulting in
inflammation and obstruction.
Radiology – US and radionuclide studies usually suggest the correct
diagnosis.
Complications – ascending cholangitis, cirrhosis, 20-fold increased
risk of carcinoma of the biliary tree, spontaneous cyst rupture.
Is this another choledochal cyst?
Clinical History:
• 4 year old presenting with 1 week of crampy, intermittent abdominal pain and
vomiting.
• Patient was found to have an intussusception which was reduced. Patient was admitted
for observation, and admission labs revealed elevated liver function tests and bilirubin
levels. Ultrasound was initially performed which then prompted this MRCP.
•The cause of the biliary
dilatation is the large
filling defect in the distal
common bile duct. This
represented a large stone.
•The stone is well seen on
these axial T2 images.
Obstructing CBD stone
• Cholelithiasis in children is
uncommon. Causes include: total
parenteral nutrition, diuretics, dehydration,
infections, hemolytic anemia, kids with
short gut syndrome, inflammatory bowel
or cystic fibrosis, patients with congenital
abnormalities of the biliary tree,
antibiotics and idiopathic.
•
Ultrasound is a first line diagnostic tool,
however MRCP is more sensitive for
evaluating the entire biliary tree and to
localize the obstructing stone.
Clinical history:
The patient presented with a fever of unknown
origin. The chest x-ray was notable for a
subpulmonic effusion which prompted
evaluation for a possible liver abnormality.
•CT scan demonstrates a
slightly irregular, intrahepatic
cystic lesion with a thick,
enhancing wall.
•Infection or tumor?
•As far as tumors go…
•Hemangioma? – this doesn’t have the typical peripheral nodular enhancement.
•Hemangioendothelioma – could have this appearance, but seen in kids < 6 months.
•Mesenchymal hamartoma – this benign liver lesion is commonly multilocular.
•Hepatoblastoma – patient should be less than 3 years old and these usually have a
more solid appearance (as does hepatocellular carcinoma).
•Solitary metastasis – not likely.
•Infection or tumor?
•As far as infection goes…
•Pyogenic abscess – would look like this, however more commonly is seen in the
immunocompromised which our patient was not.
•Fungus and cat-scratch infection – more commonly multiple small, ill-defined,
hypodense nodules.
•Parasitic infection:
•Echinococchal – can be simple appearing, however also known to have
multiple daughter cysts and commonly wall calcifications.
•Amebic – unilocular, solitary, usually in the right lobe of the liver and
commonly have a peripheral hypoechoic “halo” around the lesion (edema).
Hepatic amebic abscess
• The radiographic findings fit the pathologic diagnosis, as
the lesion is a solitary, unilocular, hypodense lesion with a
peripheral “halo” of edema.
• Caused by the parasite Entamoeba histolytica.
• Infection is via the intestines with the liver secondarily
infected via spread through the portal vein.
• More common in kids under 3 years of age.
• Ultrasound is usually diagnostic.
Clinical history:
Adolescent male from India who presented with
abdominal pain. Diagnosis?
Echinococcal cyst
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Also known as hydatid disease.
Infestation by the larval state of the Echinococcus tapeworm.
The pathologic findings explain the imaging findings.
– There are 3 layers surrounding clear fluid. There is a rigid outer layer, a
middle acellular layer and a thin inner layer in which the daughter cysts
arise.
• Therefore, the split wall appearance is
the inner wall detaching from the middle
layer.
• CT may also show daughter cysts and
wall calcifications.
• Treatment can now be done with
medical therapy, surgical removal or
percutaneous drainage.
Clinical history:
3 year old boy presented
with palpable abdominal
mass.
Differential
diagnosis?
Findings:
•There is a well defined cystic mass with thin septations and no significant
enhancement or calcifications are seen. This is within the liver as you can
see a thin rim of normal liver tissue that surrounds the lateral border of the
lesion.
•This has a nonaggressive appearance and may represent a multilocular cystic
mass of mesenchymal hamartoma or possibly hydatid disease with multiple
daughter cysts.
Mesenchymal hamartoma
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Account for nearly ¼ of benign liver tumors in childhood.
Presents in kids less than 2 years of age, with an asymptomatic
abdominal mass.
US or CT demonstrates a multi-septated cystic mass, more commonly
in the right lobe. The noncystic portions will enhance with intravenous
contrast material.
There is documented transformation of this
benign tumor into its malignant counterpart,
undifferentiated embryonal sarcoma,
however some still advocate conservative
treatment. Surgical removal is the norm.
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Non-organ based peritoneal
cysts, press the spacebar or enter
Clinical history:
•Teenager
presenting with
right lower
quadrant pain
and fever.
•Diagnosis?
Plain film demonstrated classic findings of air-fluid levels with a mottled
appearance, and a calcification in the right lower quadrant representing
appendicitis with abscess formation – well seen on the above CT scan.
Different patient: CT shows inflamed appendix
with appendicolith and adjacent free fluid.
CT 8 days later –
development of
intra-abdominal
abscess.
Appendicitis with abscess
formation
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At our institution, the first exam is ultrasound, and should be in the
pediatric patient.
US criteria – non-compressible, blind-ending structure, >6mm in
diameter, +/- hyperemia.
US findings suggesting perforation/abscess – periappendiceal or
intraperitoneal fluid, mass of mixed echogenicity.
If US non-diagnostic or patient is very large, then a CT scan with
intravenous contrast only is performed at our institution.
CT criteria – enhancing appendiceal wall, diameter >8mm.
Plain film findings – splinting resulting in scoliosis with the concavity
toward the side of pain, focal ileus/dilated right lower quadrant (RLQ)
loop, air-fluid level or mottled appearance in the RLQ if an abscess has
formed, distal small bowel obstruction, appendicolith.
•Clinical information: 3 month old female with cystic abdominal mass seen
on prenatal ultrasound, patient is asymptomatic.
• What is your differential diagnosis?
•Description: anechoic mass with enhanced through
transmission and well defined hyperechoic wall, doppler
imaging (not shown) demonstrated no vascularity.
•The lesion was adjacent to bowel and did not seem to arise
from a solid organ.
Differential diagnosis of a cystic mass in the
right upper quadrant in an infant
• types of developmental/mesenteric cysts:
• lymphangioma, enteric, mesothelial,
duplication or nonpancreatic
pseudocysts
•meconium pseudocyst
•choledochal cyst
•adrenal hemorrhage
Duplication cyst
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Developmental cysts that, by definition, contain mucosal and muscular layers.
The majority do NOT communicate with the bowel lumen.
Most frequent location is the terminal ileum or ileocecal valve.
Patient can present with bowel obstruction, peptic disease or GI bleed (if cyst
contains gastric mucosa), intussusception and volvulus.
US – anechoic cyst, +/- echogenic debris - if there is an echogenic layer
(mucosa) surrounded by a thin hypoechoic halo (representing the muscular
layer) = “gut signature,” this can suggest the diagnosis.
Cysts containing gastric mucosa can be identified on technetium-99m
pertechnatate scintingraphy, and can be a cause of a false-positive study for a
Meckel’s diverticulum.
This is another case of a duplication cyst with
the typical “gut signature” on ultrasound. The
Meckel’s scan was also positive (focus of
activity in the right lower quadrant). A
duplication cyst which contains gastric mucosa,
is a not uncommon false positive on a nuclear
medicine study for Meckel’s diverticulum.
•CT scans from two different patients - both demonstrate
cystic lesions with enhancing walls, characteristic of
duplication cysts.
•CT is not commonly indicated in the diagnostic work-up.
Can you put these findings
together to tell the clinical story
and explain what these cystic
lesions are?
What is that catheter?
Did you notice the completely
calcified native right kidney and
an atrophic left native kidney?
Clinical history:
•15 year old with end stage
renal disease secondary to
congenital nephrotic
syndrome. Patient is status
post failed renal transplant,
and is now on hemodialysis
due to transplant failure.
The catheter was a
transhepatic dialysis
catheter. These large cystic
masses represent loculated
ascites.
Clinical history:
Teenager with right lower quadrant pain. No fever or elevated
white blood cells.
There is a nonenhancing cystic lesion in the right lower
quadrant that does not have a well-defined wall or
adjacent inflammation. The differential is long and
includes duplication cyst, mesenteric cyst,
lymphangioma, or possibly a cyst related to the ovaries.
Mucocele of the Appendix
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This was only diagnosed with pathology.
Mucocele = distension of the appendix with sterile mucus.
Multiple theories on the etiology: cystic dilatation of the lumen by
obstruction, mucosal hyperplasia, mucinous cystadenoma
/adenocarcinoma, accumulation of thick mucus in cystic fibrosis.
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Incidence – 0.07-0.3% of appendectomy
specimens.
Common to see rim calcifications.
Not common in the pediatric age group.
CT – round, sharply defined paracecal mass with
homogeneous decreased attenuation.
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Clinical history:
•5 year old boy with
progressive abdominal
distension over many years.
He presented to the
emergency department with
colicky abdominal pain.
The patient has no
significant past medical
history.
•Do you see an abnormality
on this supine abdominal
radiograph?
Findings:
There is abnormal mass
effect with displacement of
loops of bowel into the right
upper quadrant.
Sagittal panoramic view
•An ultrasound was initially performed that demonstrated a
large cystic lesion that fills the entire abdomen, extending
down into the pelvis, to just above the bladder. The lesion
was avascular and contained some echogenic debris.
•A CT scan was also performed which noted a
large, non-enhancing simple cystic lesion which
fills the entire abdomen. The bottom left image
demonstrates that the lesion does not arise from
any of the major abdominal organs.
Mesenteric Lymphangioma
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The patient went to surgery and a massive cystic mass was removed
which arose from the mesentery. Chylous fluid was aspirated.
Pathologic diagnosis: lymphangioma.
These are congenital malformations of lymphatic vessels.
They are lined by endothelium only, are
commonly multi-septated and may contain chyle.
The septations are best seen with ultrasound (see
image on the right).
Commonly presents as painless abdominal
distension with a palpable mass.
Clinical history:
1 month old baby girl who was seen by her
pediatrician for vomiting, decreased appetite
and crying. On physical examination, the
infant would cry when the abdomen was
palpated. Patient was sent to the emergency
department for evaluation.
•Ultrasound noted a nonvascular,
complex cystic mass in the right lower
quadrant, with septations and
echogenic debris layering posteriorly.
•Differential diagnosis?
•A complex mass in the pelvis of a
female infant who is symptomatic
with presumed abdominal pain due
to crying on palpation of the
abdomen, should raise a red flag to
the radiologist, that there is either
torsion of the cystic mass or the
lesion has bleed or become
infected.
• Since the mass is in the right lower
quadrant, our primary consideration
was a right ovarian cyst with torsion.
Other developmental cysts that have
torsed or become complicated were
also a consideration.
Omental cyst with torsion
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Omental cyst and mesenteric cyst are used interchangeably.
Different types of mesenteric cysts include lymphangioma,
nonpancreatic pseudocyst, duplication cyst, enteric cyst and
mesothelial cyst.
Histologic evaluation will usually distinguish the subtypes.
These are developmental cysts resulting from failure of mesothelial
peritoneal surfaces to coalesce.
Unilocular, thin-walled, and can contain, serous, chylous or
hemorrhagic fluid.
Torsion, hemorrhage and bowel obstruction are complications.
Best evaluated with ultrasound, however determining the subtype of
mesenteric cyst is best done with histology.
Clinical history:
•17 year old boy with a
ventriculoperitoneal (VP)
shunt for hydrocephalus, now
presents with increasing
abdominal fullness and pain.
•Do you see the abnormality
on this scout film from the CT
scan?
The VP shunt has already been
externalized (arrow). There is
abnormal mass effect on the
bowel which is displaced
laterally (arrowheads).
Ultrasound was performed. In kids with VP shunts, always look at the
distal end of the shunt to look for loculated fluid collections around the
tip (CSF pseudocyst/ “CSFoma”). As you can see, there is a large
fluid collection around the distal tip of the catheter (arrow), which
appears loculated.
The CT scan also demonstrates the loculated
fluid collection in the mid-abdomen. Some
abdominal fluid in kids with VP shunts is
normal, however the fluid should be freely
flowing and disperse in gravity dependent areas,
and not appear as a well-defined loculated fluid
collection. Note the VP shunt (arrows) has
already been externalized because there was a
concern for infection of the fluid.
See the nice correlation between the scout film and the coronal reformation from the CT scan.
CSF pseudocyst / CSFoma
• There are many common complications related to
ventriculoperitoneal shunts: malfunction (mechanical or
occlusion), infection, CSF loculation, visceral perforation
and shunt migration.
• CSF pseudocysts form when adhesions develop around the
tip of the shunt tubing with eventual encapsulation of fluid
and obstruction of the shunt.
• Ultrasound is the most common study for diagnosis. The
shunt tubing has a characteristic appearance of several
parallel echogenic lines.
This is a different patient with a
complex CSFoma – note the
thickened wall and septations.
The echogenic lines are the tip
of the VP shunt (arrow).
Clinical history:
• Adolescent male with trauma
to the abdomen after falling off
a bicycle and onto the
handlebars.
• Diagnosis?
Duodenal hematoma
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This is a classic appearance of a large duodenal hematoma which
appears as a dumb-bell shaped cystic lesion along the expected course
of the horizontal duodenum.
This is the region of duodenum that is most commonly injured. A
blunt abdominal injury results in compression of the horizontal
portion against the spine.
The hemorrhage is intramural in location, typically through a
partial-thickness tear.
Usually managed non-operatively.
CT appearances include focal bowel wall
thickening or this dumb-bell shaped
lesion in large hematomas.
Can be evaluated with fluoroscopic
barium exam, ultrasound or CT.
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Urinary tract, press the spacebar
or enter
Clinical history:
bladder
•13 month old female
with fever, abdominal
pain and focal redness
along the anterior
abdominal wall.
Sag bladder
•Ultrasound
noted a
complex cystic mass
directly superior to the
bladder, along the
midline anterior
peritoneum. The cyst
contained echogenic
material/debris.
•Diagnosis?
Sagittal contrast filled
bladder
•A contrasted CT scan was also performed as
the etiology of the mass was uncertain.
•CT noted a cystic mass with a thick
enhancing wall just superior to the bladder,
extending along the anterior abdominal wall.
The key finding is that this entends from the
dome of the bladder into the region of the
umbilicus.
Infected Urachal cyst
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Urachal remnants result from failure of the urachus (median umbilical
ligament) to regress. The urachus is the channel between the bladder and the
embryonic allantois.
This can be open anywhere along the tract from the bladder to the umbilicus.
A patent urachus if the entire tract is open, urachal sinus if the proximal
portion is open and communicates with the umbilicus, urachal diverticulum
if the distal portion near the bladder is open (and communicates with the
bladder). The urachal cyst (the most common type) is a patency along the
midportion.
These are frequently isolated lesions, however are not uncommonly seen in
prune-belly syndrome.
Complications include infection and development of malignant
lesions (most commonly adenocarcinoma).
Evaluation is best done with ultrasound, voiding cystogram or
direct fistula study with fluoroscopy.
Clinical history: 2 month old female with
decreased urine output and left flank swelling.
Previously treated for UTI.
The CT demonstrates a duplicated left kidney
with obstructed upper pole moiety and pararenal
fluid collection. This was thought to represent a
urinoma, which was verified by nuclear
scintigraphy (see next slide).
The nuclear medicine renogram, in the posterior projection, demonstrates uptake and excretion of
radiotracer by both kidneys. Note that there is a focus of activity along the lateral upper border of
the left kidney that slowly forms and is best seen around slide #6. This area is persistent even after
radiotracer has washed out of the kidneys on the later portion of the exam.
Duplicated kidney with urinoma
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Duplication of the kidney is one of the most common
anomalies of the urinary tract. There is a wide spectrum of
partial and complete duplication anomalies, that should be
very familiar to the pediatric radiologist.
The Weigert-Meyer rule refers to the insertion of the ureters
of a duplicated system. The ureter to the upper pole moiety
inserts inferior and medial to the ureter of the lower pole
moiety, which inserts normally. The ureter of the upper pole
tends to obstruct (usually by an ectopic ureterocele), and
there is reflux into the lower pole moiety.
A urinoma is a result of acute or chronic obstruction or
trauma to the intrarenal collecting system, resulting in
forniceal rupture.
This is another case of a
duplicated kidney, with marked
obstruction and dilatation of the
upper pole moiety and its ureter,
by a large ureterocele.
Selected images from this patient’s nuclear medicine
renogram demonstrate a photopenic defect (arrow) in the
upper pole of the right kidney, representing a completely
non-functioning obstructed upper pole moiety.
This is the second most common cause of an abdominal mass in the
neonate, after hydronephrosis (usually from a ureteropelvic junction
obstruction). Diagnosis?
The ultrasound shows multiple cysts, of varying sizes, in the left renal
fossa. The key is that these cysts do NOT communicate (to help
differentiate from severe hydronephrosis). There is no normal intervening
renal parenchyma. This is a classic appearance for multicystic dysplastic
kidney (MCDK).
•This nuclear medicine renogram from a
different patient, shows the classic
appearance of an MCDK on scintigraphy.
By definition, there is NO function, so
there will be no uptake of radiotracer by
the involved kidney. Time-activity curves
will obviously be abnormal.
•Most commonly MCDK is unilateral,
however in 20-30% of cases, there is an
associated anomaly of the contralateral
kidney!
This is another appearance of a right multicystic
dyplastic kidney. This is one of the 20-30% of
patients with contralateral abnormalities: in this case,
moderate hydronephrosis due to vesicoureteral
reflux.
Clinical history:
Child presented with
trauma, status post motor
vehicle collision. No past
medical history.
•In contradistinction to the last case, the large cysts involving this kidney do
connect.
•CT is notable for a markedly dilated renal pelvis, to a greater degree than the
calyces. There is a rounded appearance to the pelvis as well. This is a typical
appearance for a ureteropelvic junction obstruction (UPJ). As there was an
initial obstruction, the subsequent trauma to the abdomen resulted in an
acquired urinoma, presumably from forniceal rupture.
UPJ obstruction
• The most common cause of an abdominal mass in a
neonate.
• More commonly seen in boys and on the left side.
• Bilateral in 10-20% of cases and up to 30% are associated
with other renal anomalies.
• Ultrasound is the diagnostic study of
choice. Nuclear medicine renogram is
useful to evaluate for function.
Here is another interesting cause of
an acquired cystic lesion (urinoma)
in the abdomen.
Clinical history: Teenager who
presented with trauma (thrown from
a snowmobile).
The contrasted CT scan demonstrates a horseshoe kidney,
which due to the blunt abdominal trauma, resulted in a
complete laceration through the mid-portion with a large
urinoma.
bladder
Clinical history: 11 month old boy with urinary tract infection.
•Sonographic images of the bladder in the sagittal plane, demonstrate a cystic
lesion at the right posterolateral base of the bladder that changes shape with
voiding.
•Diagnosis? What test would you perform next?
The two upper images
demonstrate focal
outpouching of contrast
along the posterior inferior
right side of the bladder
during early bladder filling.
This represents a large
bladder diverticulum near the
right ureterovesicular
junction (UVJ).
Early bladder filling
Post-void
The voiding and post-void
images to the left,
demonstrate a smaller
diverticulum in the region of
the left UVJ. The larger
diverticulum decompresses
nicely after voiding.
Bilateral Hutch diverticula
• These are “pseudodiverticula” – localized outpouchings
of the mucosa between detrussor muscle fibers. These can
be congenital or acquired.
• The Hutch type is a common primary paraureteral
diverticulum, located laterally and cephalad to the ureteral
orifice.
• Vesicoureteral reflux is present in about half of the cases.
• Diverticula are best seen during voiding when bladder
contractions force urine into the diverticulum.
Clinical history:
2 year old who presented
with palpable abdominal
mass.
The axial image to the left is
non-contrast, and demonstrates
a large low density/cystic mass
in the region of the right renal
fossa. Faint calcifications are
seen.
The axial image to the right is
post-contrast. The mass has
minimal peripheral
enhancement. Note the “claw”
sign of the kidney, which
appears to wrap around the
mass (arrows), suggesting the
lesion arises from the kidney.
Wilms tumor
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The most common abdominal malignancy of childhood.
Usually presents as a palpable mass in a toddler.
Children at increased risk include those with nephroblastomatosis,
syndromic kids including Beckwith-Wiedemann, Drash and WAGR
syndrome, and kids with sporadic aniridia or hemihypertrophy.
• Radiologic evaluation, commonly with CT, is focused on identifying
the sites of involvement, extension and
metastases in order to assist in surgical planning.
• CT characteristics: well-circumscribed,
heterogeneous partially cystic mass, may contain
fat or calcifications, enhances to a lesser degree
than the renal parenchyma. Look for nodal or
hepatic metastases, tumor extension into the IVC
or renal vein and contralateral tumors.
Clincial information:
•14 year old boy with 2 weeks of
worsening left upper quadrant sharp,
intermittent pain.
•Diagnosis?
Diagnosis: Renal abscess
•There is a complex, multi-septated
cystic intrarenal lesion with enhancing
walls and inflammatory change in the
perirenal fat, with an adjacent abscess
anterior to the kidney.
Renal abscess
• The patient failed medical treatment so both abscesses
were drained separately. Culture was positive for Proteus
mirabilis.
• Abscess is a rare complication of pyelonephritis.
• More often seen in immunocompromised, or kids with
diabetes or sickle cell disease.
• US – hypoechoic mass with good through transmission,
wall will thicken as the process progresses.
• CT – low density lesion, +/- enhancing wall, different
from focal pyelonephritis in that they are not wedge
shaped.
• Differential diagnosis would be a cystic Wilm’s tumor.
End of this section
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References
Caffey’s Pediatric Diagnostic Imaging,
10th edition, Kuhn et al., 2004.
Pediatric Sonography, 3rd edition, Siegel,
M., 2002.
Radiology Review Manual, 5th edition,
Dähnert, W., 2003.