CARCINOMA EX PLEOMORPHIC ADENOMA IN PAROTID GLAND

Journal of Experimental Medical & Surgical Research
Cercetãri Experimentale & Medico-Chirurgicale
Year XVII · Nr.3/2010 · Pag. 205 - 209
JOURNAL of
Experimental
Medical
Surgical
R E S E A R C H
CARCINOMA EX PLEOMORPHIC ADENOMA IN
PAROTID GLAND – CASE REPORT
A. Mag1
S. Cotulbea1
A. H. Marin1
C. Doros1
D. Neamtu1
N. Balica1
A. Ruja2
M. Preda3
SUMMARY:
Carcinoma ex pleomorphic adenoma is defined as a pleomorphic adenoma from which
derived an epithelial malignancy. This tumor develops in primary or recurrent pleomorphic
adenoma. Carcinoma ex pleomorphic adenoma is rare and comprises approximately 3.6%
of all salivary tumors. The authors present a case of carcinoma ex pleomorphic adenoma,
which is one of the 6 cases of carcinomas ex pleomorphic adenoma that have been
operated in ENT Department Timiºoara over the last 10 years, emphasizing diagnostic steps
taken and therapeutic methods. We present the case of a 63 year old female from urban
area who was admitted to hospital for a mass in the parotid region, witch appeared so, after
seven months, gradually increasing in size. At MRI examination appeared an expansive
polilobulated tumor mass with axial diameters of 4/5 cm, in the left parotid gland projection.
We performed total left parotidectomy with facial nerve preservation and lateral neck
dissection Level II – IV. Histopathological exam revealed mucoepidermoid carcinoma ex
pleomorphic adenoma. The evolution of this tumor presents a high aggressiveness, the
patient undergone postoperative radiotherapy, respectively.
Key Words: carcinoma ex pleomorphic adenoma, malignant parotid tumor, parotidectomy
CARCINOM EX ADENOM PLEOMORF PAROTIDIAN – PREZENTARE DE CAZ
Received for publication: 01.05.2010
Revised: 21.07.2010
Rezumat:
Carcinomul ex adenom pleomorf este definit ca adenom pleomorf în care apar elemente
maligne strict epiteliale. Acesta se dezvoltã în adenom pleomorf primar sau recurent.
Carcinomul ex adenom pleomorf este rar ºi reprezintã aproximativ 3,6% din toate tumorile
glandelor salivare. Autorii prezintã un caz de carcinom ex adenom pleomorf, dintre cele 6
cazuri diagnosticate ºi operate în Clinica ORL Timiºoara în ultimii 10 ani, subliniind etapele
diagnostice parcurse, precum ºi modalitatea terapeuticã utilizatã. Prezentãm cazul unei
paciente în vârstã de 63 de ani din mediu urban, ce a fost internatã în Clinica ORL Timiºoara
pentru o formaþiune tumoralã în regiunea parotidianã stângã, apãrutã, afirmativ, în urmã cu
aproximativ ºapte luni înaintea internãrii, crescând treptat în dimensiuni. Examinarea RMN
a evidenþiat o masã tumoralã expansivã cu contur polilobulat cu diametrele axiale maxime
de 4/5 cm., în proiecþia glandei parotide stângi. S-a efectuat parotidectomie totalã stângã cu
conservarea nervului facial ºi evidare ganglionarã funcþionalã selectivã parþialã stângã
(ariile II-IV). Examenul histopatologic a relevat: carcinom mucoepidermoid ex adenom
pleomorf. Evoluþia acestei tumori prezintã o agresivitate crescutã, motiv pentru care s-a
indicat efectuarea de radioterapie postoperator.
Cuvinte-cheie: carcinom ex adenom pleomorf, neoplasm parotidian, parotidectomie totalã.
1. - ENT Department, University of Medicine and Pharmacy Timiºoara
2. - Clinic of Odontotherapiy, Faculty of Dentistry, University of Medicine and Pharmacy Timiºoara
3. - Clinic of General and Oncologic Surgery, University of Medicine and Pharmacy Timiºoara
INTRODUCTION
the major salivary glands. (1,2). These tumors occurs
most frequently in the parotid gland. Most pleomorphic
Pleomorphic adenoma, also know as benign mixed
adenomas of parotid gland develop in the superficial
tumor because of the presence of both epithelial and
parotid lobe. Generally they presents as a well-deliniated,
mesenchymal tissue, are the most common tumors of
solitary, painless mass with slow growth. (3). Although
Correspondence to: Dr. Anamaria Mag, Clinica ORL Timiºoara, Bd. Revoluþiei No. 6, Telefon: 0740 43 47 40,
Email: anamariamag@yahoo.com
205
benign, as many as 25% undergo carcinomatous
transformation, if left untreated. (2). Pleomorphic
adenoma can sometimes to recur, metastasizes or suffer
malignant degeneration. (3). Carcinoma ex pleomorphic
adenoma is usually a more poorly circumscribed mass
than the benign pleomorphic adenoma. Carcinomas ex
pleomorphic adenoma are prone to frequent recurrence
and commonly metastasize. (3).
We made a study of all malignant tumors of parotid
gland tumors treated in ENT Department Timiºoara
between 2002 to 2009. From 26 cases of malignant
parotid tumors, only six represented carcinomas ex
pleomorphic adenoma. We decided to make this case
report because of the rarity of carcinoma ex pleomorphic
adenoma in malignant tumoral pathology of parotid
gland.
CASE PRESENTATION
S.M. patient, aged 63 years, from urban area, was
admitted in the ENT Department Timiºoara in August
2008 for a mass in the parotid region, which appeared,
after seven months, gradually increasing in size. We have
to mention that the patient did not present at admission
facial palsy or ear sensory disturbances.
E.N.T. Clinical Exam:
Inspection: deformation of the left parotid gland region
by a tumor with size of 4/5 cm.
Palpation: reveals a tumor size of 4/5 cm, well
circumscribed with hard consistency, fixed to deep
planes, sensitive to palpation. The superjacent skin
aspect was normal. (Fig. 1)
Bucopharyngoscopy,
anterior
and
posterior
rhynoscopy, indirect laryngoscopy, nasal endoscopy,
hypopharingo-laryngo-endoscopy with 70 degree
endoscope revealed no pathological evidence.
General examination reveals no pathology.
Fig. 2(b) MRI
206
Fig. 1 Left parotid tumor
Fig. 2(a) MRI
Fig. 3 Area of mucoepidermoid carcinoma ex pleomorphic
adenoma immunopozitive for Ki67
Laboratory examination reveals a minor anemia but no
other change in biological constants. Chest X-ray shows
no active or disabling pleuropulmonary lesions.
MRI examination (Fig. 2a end 2b) is performed and
reveals an expansive, polilobulated tumor mass with
axial diameters of 4/5 cm, in the left parotid gland
projection; the formation shows heterogeneous
hypo-signal in T1, with fluid signal infracentrimetric areas
(necrosis) co-existing with hemorrhage lesions on T1
hyper-signal; in T2 nonhomogeneous hyper-signal,
heterogeneous
gadolinophilly
of
areas
with
parenchymatous signal and the absence of signal in
areas of necrosis contrast intake.
With these clinical and laboratory data we establish
presumptive diagnosis of left parotidian tumor, possibly
malignant.
Regarding differential diagnosis, other diseases that
could enter into discussion are: secondary lymph node
from septic processes of the mouth, chronic parotitis,
syphilis, tuberculosis and actinomicosis, Hodgkin’s
disease, lymphosarcoma, metastatic tumors, primary or
Fig. 4a Intraoperative aspect
metastatic
melanoma,
angiomatosis
tumor,
neurofibroma.
Based on these data, with patient consent, surgical
intervention is decided. Total parotidectomy was
performed with preservation of facial nerve and left
lateral neck dissection II-IV. (Fig. 4a and 4b)
Postoperative evolution, under antibiotic therapy and
daily wound toilet, was good with healing per primam.
The tumor removed was sent to hystopathological
examination which revealed a microscopic structure of
mucoepidermoid carcinoma ex pleomorphic adenoma
associated with small fragments of salivary gland with
lesion of pleomorphic adenoma; tumor is invasive in
adjacent tissues of glandular lodge, for which
postoperative
radiotherapy
was
indicated.
Immunohistochemical study revealed for Ki 67 a positive
immune reaction. (Fig. 3).
The particularity of the case is represented by the
rapid evolution of the tumor mass (seven months), since
the most studies, highlights most often, a significantly
longer evolution.
DISCUSSIONS
Pleomorphic adenoma is the most common benign
tumor that affects salivary glands (1,2), occuring on
60%-70% of cases. Pleomorphic adenoma is
characterized by proliferation of epithelial-mesenchymal
tissue of the salivary gland.
Occasionally pleomorphic adenoma may undergo
malignant transformation resulting carcinoma ex
pleomorphic adenoma or respectively carcinosarcoma.
Very occasionally however, metastatic lesions are
identified in patients with a history of pleomorphic
adenoma which, on detailed pathological evaluation, are
found to exhibit all the histological hallmarks of the
Fig. 4b. Intraoperative aspect
207
preceding benign lesion. This “enigmatic” entity has been
termed the metastasizing pleomorphic adenoma. (4).
In recent years appeared datas about non-invasive (in
situ or intracapsular) carcinoma ex pleomorphic
adenoma. (5). They are carcinomas occurring in the
pleomorphic adenoma without penetrating the capsule.
Although encapsulation of tumor proved to be a indicator
of benign character, Felix et al. (5) recently reported a
case in which a fully encapsulated carcinoma ex
pleomorphic adenoma presented regional lymph nodes.
Carcinoma ex pleomorphic adenoma usually occurs in
men in six decade of life. (6).
Approximately 80% are located in major salivary
glands and 20% in small salivary glands. (7). Most cases
(81,7%) occur in the parotid gland, while a 18%,
respectively 0,3% appear in submandibular and
sublingual gland. (8). Most series show a female to male
ratio of 1.2 to 3.1. (9). Carcinoma ex pleomorphic
adenoma rarely occurs before age of 20 years. (10).
Usually presents as a mass with a long evolution that
shows a sudden increase in size. In 12-55% of cases this
rapid increase in size may be accompanied by pain, facial
nerve palsy and fixation to the surrounding soft tissue. A
small percentage of patients may have tumors with rapid
growth, without any symptoms. (10). Zbaren et al. in a
group of 24 patients with carcinoma ex pleomorphic
adenoma noted a percentage of 33% (8 cases), when
tumor was in parotid deep lobe. (11).
Eneroth and Zetterberg’s studies support the
hypothesis that the risk of carcinomatous transformation
in a adenoma increases with the age of the tumor. (12).
Histological features of carcinoma ex pleomorphic
adenoma are: the capsule invasion, hemorrhage,
necrosis alternating with areas presenting classical
features of pleomorphic adenoma. (13). Recent studies
have shown that the most frequently encountered
histological types in a carcinoma ex pleomorphic
adenoma are: highly malignant adenocarcinoma or
undifferentied carcinoma, although many other types
were found such as squamous cell carcinoma,
mucoepidermoid carcinoma, adenoid cystic carcinoma,
papillary carcinoma and terminal duct carcinoma. (14).
Carcinoma ex pleomorphic adenoma treatment is
surgical – parotidectomy with neck dissection.
Some authors (15,16) recommended surgery and
postoperative radiotherapy, which is also our opinion in
treatment of this tumors. Chen and colab. (15) have
obtained a better local tumor control from 49% to 75% by
combining surgery with postoperative radiotherapy in 63
patients diagnosed with carcinoma ex pleomorphic
adenoma.
Features associated with an unfavorable prognosis
include: high tumor grade, large size, soft tissue invasion,
perineural invasion and lymph node metastases.
According to LiVolsi and Perzin (17) the extent of tumor
infiltration beyond the capsule is the most reliable
prognostic marker. Carcinoma ex pleomorphic adenoma
metastasizes exclusively as a carcinoma. Distant
metastases occur more frequently than regional
metastases. Distant metastases seem to show a
particular affinity for lung and bone, especially the
vertebral column. (18).
Zbaren et al. (11) observed in 24 cases of carcinoma
ex pleomorphic adenoma studied, a survival rate of 76%
at 5 years and a recurrence rate of 25% (six of 24
patients). Luers et al. (19) retrospectively analyzed 22
cases of carcinoma ex pleomorphic adenoma, found that
about half of patients had evidence of a parotid mass of
up to 1 year only while maximum of the others was 48
years. Both 5-year disease-specific and overall survival
were 60%. Recurrence-free survival after 5 years was
85%.
CONCLUSIONS
The fact that pleomorphic adenomas are classified as
benign tumors should not overshadow the wide range of
biologic behaviors associated with these tumors.
Because of the potential for malignant transformation,
surgical treatment must be properly performed.
Surgery followed by postoperative radiation should be
considered the standard of care for patients with
carcinoma ex pleomorphic adenoma.
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