Management Strategies - Healthcare Professionals

Management of Abdominal
Incidentalomas Found on Cross-sectional
Imaging: Management Strategies
• Michael Nipper, M.D.
Q1: What Percentage of the Time Does
My Radiology Group Give Specific
Follow-up Recommendations for
Incidental Findings?
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1. A. 5%
2. B. 20%
3. C. 50%
4. D. 75%
5. E. 100%
Definition
• Incidentaloma: “unsought information generated in the seeking of the
information one desires.”
• Or: “an incidentally discovered mass or lesion, detected by CT, MRI
or other imaging modality performed for an unrelated reason.”
• Detection of incidental lesions may or may not be beneficial to the
patient:
– AAA
– Renal hypodensities
– Davis DS. Medicine and Philosophy 2007
– Werth B. Damages 1998
What is Incidental?
• No known malignancy in the patient
• No signs or symptoms referable to the
finding
– A renal mass found in patient with hematuria is
not incidental
• Infection is not clinically suspected
Q 2: Which of the Following Factors
Should be Mentioned by the Radiologist
when He Recommends Follow-up?
• 1. A. Time frame to follow-up
• 2. B. Modality of follow-up
• 3. C. Likelihood of the lesion being
malignant
• 4. D. Both A and B
• 5. E. All three
Incidentalomas: The Radiologist’s
Recommendations Should Be:
• Broadly accepted
• Easy to access
• Straightforward to understand and apply
– Which modality
– Timing of follow-up
– Likelihood of lesion being significant
CT Scanning “Handicaps”
Nowadays : IV Contrast
• The classic definition of a cyst on CT scanning
– Homogeneous, circumscribed, no thick wall or septation
– NCCT: Density under 20 HU
– CECT: May enhance 10 HU with IV contrast enhancement
• Most protocols now are NCCT or CECT only
– Thank you CMS!
– The old definitions for a cyst do not apply
• Most radiologists are NOT recommending bringing back
patients for full assessment of hepatic, renal or splenic
hypodense lesions 1 cm or less
Chuck of All Trades
Incidental Renal Masses
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No history of malignancy
No added risk factor for renal malignancy
No clinical suspicion of infection
No GU signs or symptoms
Renal Oncocytoma
Incidental Renal Masses
• Lesion under 1 cm and low density: presumed cyst
– “Subcentimeter renal hypodensity which is too small to fully
characterize but which statistically represents a tiny renal cyst”*
– If you must image further: MRI, not US for tiny ( 8 mm and under)
hypodensities in the kidney or liver
• Any amount of fat in the lesion on imaging:
angiomyolipoma (AML)
– Review the CT with the radiologist
– MRI is useful to detect small amounts of fat
• Hyperdense masses: biopsy, AML with minimal fat
• Exclude infection as a cause
– * Silverman, et al. RCNA Imaging of Incidentalomas. March 2011
p. 375.
Incidental Cystic Renal Masses:
Bosniak Criteria
• Lesions over 1 cm: use Bosniak criteria
– Bosniak 1: simple cyst
– Bosniak 2: hyperdense, one or two thin septations, thin septal or wall
calcification
– Bosniak 2f: many septations, thick wall or septation, thick calcification,
but no suspicious enhancement
– Bosniak 3: complex cystic mass, about half are malignant
• Needle biopsy (AML with minimal fat) or Urology consultation
– Bosniak 4: solid component, presumed RCC, Urology consultation
• If under 1 cm: follow (6 months X2, then yearly to 5 years)
• 1-3 cm: follow (elderly), surgery or percutaneous ablation
• Lesions over 3 cm: surgery (ablation?)
– Following: a change in characteristics is as important as a change in size
– Silverman, et al. Radiology 2008
Berland, et al: Incidental Cystic
Renal Mass Management
Berland, et al: Incidental
Solid Renal Mass
Incidental Solid Renal Mass:
Hyperdense Renal Mass on NCCT
• Hyperattenuating renal mass on NCCT
– Abdominal US if large enough (> 1 cm): often
due to cysts with proteinaceous fluid
– Otherwise, bring back for CECT or MRI
– Consider percutaneous biopsy of hyperdense
solid renal lesions (1-3 cm) that may go to
surgery
• May be an AML with minimal fat
Renal AML with Minimal Fat
Percutaneous Ablation
of Renal Masses
• For small peripheral renal masses
• Often percutaneous biopsy done first
• Either RFA (heating) or cryoablation
(freezing)
Chuck Norris’ Cat
Adrenal Incidentalomas
• Seen in 3-5% of abdominal CT scans
– Under 1 cm: do nothing?
• Most are benign cortical adenomas
• Most adrenal adenomas do not “function”
• Suspicious imaging findings
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Central necrosis
Heterogeneous
Irregular margins
Larger than 4 cm
Enlarging adrenal mass (except infection or hematoma)
Adrenal Incidentalomas
• Lipid rich adenomas
– Homogenous with smooth margins
– Under 10 HU on NCCT
– Signal dropout on chemical shift MRI imaging
• Lipid poor adenomas
– Homogenous with smooth margins
– Over 10 HU on NCCT
– High adrenal percentage IV contrast washout (60% absolute, 40% relative
at 15 minutes)
• Myelolipomas
– Macroscopic fat by CT or MRI
– Rare case of AML with minimal fat: hyperdense on NCCT
• PET/CT
Berland, et al:
Incidental Adrenal Mass
Adrenal Adenoma
Adrenal Washout “Calculator”
• http://www.chestx-ray.com/StagingLungCa/Adrenal.html
MRI with Chemical Shift Imaging
Chuck Norris’ Toilet Paper
Incidental Hepatic Lesions
• No known cancer
• No known added risk factors for liver
cancer
• No known liver dysfunction
• No clinical suspicion of infection
Hepatic Incidentalomas:
Flash-filling Arterial Lesions
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In a patient with no liver risk factors: benign
– Do not assess further
– Do not follow-up
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Benign causes
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THAD, THID: hepatic arterial compensation for low PV flow
Type 1 hemangioma
FNH, adenoma
Nodular regenerative hyperplasia: multiple, subcapsular
AV malformation
Shunts: AV, PV, AP
Malignant causes
– Usually Not Incidental
– Dysplastic nodule or well-differentiated hepatoma
– Hypervascular metastases
Liver Segment IV THAD
SVC Obstruction by Lung Cancer
Hepatic Incidentalomas:
The Left Lobe is a “Trouble-maker”
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Focal fatty infiltration
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Focal fatty sparing
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Seen in arterial phase only, invisible in portal venous phase
Perfusion and drainage of this portion of the liver partially by systemic blood flow
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Same distribution, see in portal venous phase only
THADS
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Same type of distribution
Perfusion defect
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Geometric, no bulging of liver capsule
Normal vessels course through area
Along falciform ligament (especially segment 4) and near GB
Internal mammary vein and paraumbilical veins
Vein of Sappey (medial diaphragm and liver segment 4)
Different trophism?
If you must image further: MRI
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Fat sequences
Hepatocyte specific contrast agents
Focal Fatty Infiltration/
Perfusion Defect Liver
Hepatic Incidentalomas
• Simple cysts: 15-20% of patients
• Bile duct hamartomas
– Under 1.5 cm
– Multiple, uniform, no enhancement
• Hemangioma
– Characteristic findings on CT or MRI
• FNH
– Characteristic findings on MRI
Simple Liver Cyst
Bile Duct Harmatomas
Liver Hemangioma
FNH Liver
MRI of FNH
MRI FNH: Hepatocyte
Specific Agents
• Multihance
– Gadobenate
Dimeglumine
– 4%
• Eovist
– Gadodexic acid
– 50%
• Taken up by
hepatocytes and
excreted into biliary
tree
Berland, et al:
Incidental Hepatic Mass
Incidental Liver Lesions on CT
• Lesion under 1 cm: no further evaluation
• Lesion over 1 cm
– Low risk:
• No further evaluation (elderly)
• Follow-up (middle-aged)
– High risk:
• Further immediate imaging with MRI or US
• Biopsy
Incidental Pancreatic Cysts
• 1-3% of abdominal CT scans demonstrate
incidental pancreatic cystic lesion
• Pancreatic cysts are seen on fluid sensitive
sequences in 13-20% of patients having
abdominal MRI
• Most are intraductal papillary mucinous
neoplasms (IPMNs, IPMTs)
– Low grade, indolent neoplasms
Imaging Classification of
Pancreatic Cysts
• Unilocular
– Pseudocyst, true cysts, small IPMNs
– Cysts under 2 cm will seem unilocular on CT
• Microcystic
– Six or more cysts under 2 cm
– Serous cystadenoma
– 30% have calcifications
• Macrocystic
– Less than six cysts over 2 cm
– Mucinous cystadenoma, adenocarcinoma
• Cystic and Solid
– Mucinous cystic tumor
– Solid pseudopapillary tumor
Small Pancreatic Cyst
Small Pancreatic Cyst
Worrisome Features of
Pancreatic Cysts
• Larger than 3 cm
– 97% of pancreatic cysts under 3 cm in asymptomatic
patients are benign
• Mural nodule
• Dilation of pancreatic duct (6 mm) or CBD
– 3 mm pancreatic duct up to 50 y/o
– 5 mm pancreatic duct after age 50
• Duct wall enhancement
• Lymphadenopathy
Berland, et al:
Incidental Cystic Pancreatic Mass
Incidental Pancreatic Cysts
• Under 2 cm
– No follow-up (elderly)
– Follow with CT in 6-12 months (middle aged)
• 2-3 cm
– CT follow-up (elderly)
– GI consultation for EUS (middle aged)
• Over 3 cm
– GI Consultation: EUS or CT follow-up
Don’t Make Chuck Mad
Incidental Splenic Lesions
• Splenic clefts, splenules, calcified
granulomas
• Cysts
– Pseudocysts: trauma, pancreatitis, old infarct
• Often thick rim of calcification
– True cysts: epidermoid, hydatid
– Under 5 cm and asymptomatic: leave alone
Splenic Hemangioma
Incidental Splenic Lesions
• Incidental splenic “masses” uncommon: under 1%
– Most lesion are not pathognomonic by imaging
• Splenic hemangioma
– 1-2 cm in size
– Most are not classic (like in the liver)
• Hamartoma
– Bulges splenic margin
– Persistent enhancement
• Lymphangioma
– Subcapsular
– Cystic and without contrast enhancement
Incidental Splenic Masses
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Lymphoma
Angiosarcoma
Littoral cell angioma
PET/CT
– Sensitivity 100%, specificity 80%
– PPV 80%, NPV 100%
• Biopsy
– Safe
Isolated Splenic Lesion in a
Patient with Known Malignancy
• Spleen is an uncommon site for metastases
(#10).
• Rare to have metastases to the spleen
without other sites (liver) of metastatic
disease
• Same is true of splenic sarcoidosis
Solitary Isolated Asymptomatic
Splenic Lesion
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Splenic cystic lesions
– Under 5 cm
• No follow-up, especially if there is a good history
– Over 5 cm
• Follow if there is no good history
• Refer to GI or General Surgery if symptomatic
Splenic solid lesions
– Under 1-2 cm
• Do nothing: elderly
• Follow with imaging: middle age
– Over 2 cm
• Characterize with splenic mass CT or MRI
• And/or follow with imaging (US?)
– PET/CT
– Biopsy
• Nipper, 2011.
Incidental Adnexal Cysts in
Asymptomatic Women:
Postmenopausal
• Postmenopausal
– One year or more of amenorrhea after final menstrual
period
– Simple cysts 1 cm or less need no follow-up
– Adnexal cysts 1-7 cm: one year follow-up
– Cysts over 7 cm: Gynecology consult or pelvic MRI
– Management of Asymptomatic Ovarian and other Adnexal Cysts
Imaged at Ultrasound. Levine D., et. al. Radiology; September
2010, 256: 943-954.
Incidental Adnexal Cysts in
Asymptomatic Women:
Premenopausal
• Simple cysts or classic hemorrhagic cysts 5 cm or
less need no follow-up
• Simple cysts or classic hemorrhagic cysts 5-7 cm:
one year follow-up
• Any cyst over 7 cm: gynecology consultation
and/or pelvic MRI
• Often, cysts over 3 cm are reported, but no followup is required
Simple and Hemorrhagic Cysts
Corpus Luteum
Chuck and I Thank You
Major References
• Imaging of Incidentalomas. RCNA. March 2011.
• Managing Incidental Findings on Abdominal CT.
ACR White Paper. JACR 2010;7:754-773.
• Management of Asymptomatic Ovarian and other
Adnexal Cysts Imaged at Ultrasound. Levine D.,
et. al. Radiology; September 2010, 256: 943-954.