Keywords
mucoepidermoid tumor - minor salivary glands - mouth
Palavras-chave
tumor mucoepidermoide - glândulas salivares menores - boca
Introduction
The Mucoepidermoid Carcinomas (MEC) represent about 5% of all tumors in the salivary
glands. They affect the intraoral major and minor salivary glands in more than 90%
of the cases[1]
[2]. In the minor salivary glands it affects specifically the roof and the floor of
the mouth, generally in the fifth decade of life and with a slight prevalence in the
female sex. The mucoepidermoid carcinomas have been histologically classified into
three degrees of malignity (low, intermediate and high degree), and such subdivision
has been proved helpful for the setting up of the therapy and in the prognosis of
such tumors[3]
[4]
[5]. The early diagnosis and the correct management of this disease are key factors
for the prognosis. It is an aggressive lesion and must be considered as a diagnosis
hypothesis in the oral mucosa proliferative lesions, even when its clinical appearance
does not suggest malignity.
Case Report
CT, 47 years old, white housewife from Italva/RJ, was forwarded to the ORL service
of the HSJA after a critical episode of bleeding in oral cavity. She reported the
appearing of a mass with fast and expansive growth in a topography of canine fossa
for +/- 06 months, associated to the loss of 10 kg. The patient was lucid, examined,
with regular general status, dehydrated (++/ + 4), pale (++/ + 4), with pediculated
tumor of +/- 06 cm ([Figure 1)], firm consistency, painless with palpation, bleeding; non-palpable cervical lymph
nodes. Chronic alcoholic and smoker, without family record of neoplasm. Faced with
the case we opted for a surgical resection of the tumor ([Figure 2]) and the performance of histopathological exam that confirmed mucoepidermoid carcinoma
of minor salivary glands of intermediate degree ([Figure 3]). The patient was sent to the radiotherapy service; but she abandoned the treatment
and evolved with death 4 months after.
Figure 1. Pediculated tumor in oral cavity.
Figure 2. Surgical piece.
Figure 3. Optical microscopy exam of the mucoepidermoid carcinoma of minor salivary glands.
Microscopy (HE 100 x).
Discussion
Mucoepidermoid carcinomas (MECs) are malignant tumors from glandular structures excrectory
ducts that affect the intraoral major and minor salivary glands in more than 90% of
the cases[1]
[2]. MEC can also occur in covering glands of the maxillary sinuses, lachrymal glands,
oropharynx, nasopharynx, larynx, vocal cords, trachea and lungs[2].
The etiopathogenesis of the MEC is unknown; however, as well as the other kinds of
cancer, the lesion results from genetic alteration, and when altered the proto-oncogenes
and the tumor suppressor genes play an important role in their pathogenesis. As procatartic
factors we include exposure to ionizing radiation, previous RT, nickel refinery, chemical
solvents, leather, sawing, formaldehyde, pollution[9]. The MEC's histopathological characteristics are: presence of squamous cells, mucus-producing
cells and intermediate cells. The predominant cellular type and its configuration
vary between the tumors and inside the same tumor mass.
Clinically, MEC may manifest as a lesion of color ranging from blue to red or purple.
The oral mucosa lesions, floor of the mouth, lips and retromolar region appear as
asymptomatic submucous masses while tongue lesions are frequently painful. The factors
relating to the MEC prognosis are: size of the primary lesion upon surgery, histological
grading of the tumor and presence of metastases.
Large local resection associated or not to cervical space and eventually postoperative
radiotherapy is the choice treatment for mucoepidermoid carcinomas[1]
[5]
[6]
[7]
[8]. The resection of adjacent structures is indicated for cases with complications
detected previously or during the surgery.
Final Comments
Such tumors have different biological behavior according to the degree of histological
differentiation, size of the lesion and presence of metastases; the early diagnosis
and the correct management are key factors for prognosis.
In this case, the fast and aggressive growth of the lesion, the size of the tumor
was critical for the patient's prognosis.
