Diagnóstico diferencial e tratamento do mioepitelioma e adenoma pleomórfico / Differential diagnosis and treatment of mioepithelioma and pleomorphic adenoma

Introdução: As neoplasias de glândulas salivares constituem um grupo de lesões, clínica e morfologicamente diferente, capaz de determinar importantes desafios diagnósticos e terapêuticos. Apresentar dois casos de tumores benignos de glândulas salivares menores, sendo um adenoma e outro mioepitelioma, discutindo o diagnóstico diferencial e a forma de tratamento em comparação com informações da literatura. Relato de caso: Pacientes do sexo feminino, com idades semelhantes, ambas se queixavam que após o uso de uma prótese mal adaptada notou-se o aparecimento de uma lesão assintomática no palato. Diante das características clínicas das lesões, as hipóteses de diagnóstico foram de tumor de glândula salivar menor e adenoma pleomórfico, respectivamente. Diante da ausência de sinais de malignidade, o tratamento proposto foi biópsia excisional com enucleação e curetagem. O diagnóstico histopatológico foi de Tumor de Glândula Salivar Menor (Mioepitelioma Plasmocitóide), e Adenoma Pleomórfico, respectivamente. A enucleação e curetagem se mostraram eficazes e sem sinais de recidiva. Considerações finais: Tanto o adenoma como o mioepitelioma se apresentam clinicamente semelhantes sendo o diagnóstico diferencial realizado através do histopatológico, porém o tratamento conservador de enucleação e curetagem pode ser aplicado em ambas... (AU)

Introduction: The neoplasms of salivary gland constitute a group of lesions clinically and morphologically different, which are able to determine important challenges in diagnostic and therapeutic.To report two cases of benign tumors of the minor salivary glands, adenoma and myoepithelioma. Also, discussing the differential diagnosis and its treatment in comparison with literature information. Case report: Two female patients, with similar ages, both complained about the appearance of an asymptomatic lesion on the palate after using a poorly adapted prosthesis. On the clinical characteristics of the lesions, the hypothetical diagnosis was of minor salivary gland tumor and pleomorphic adenoma, respectively. In the absence of signs of malignancy, the proposed treatment was excisional biopsy with enucleation and curettage. The histopathology diagnosis was begin tumor of minor salivary glands (myoepithelioma plasmacytoid), and pleomorphic adenoma, respectively. The enucleation and curettage were effective and there were no signs of recurrence. Final considerations: Both the adenoma and myoepithelioma are clinically similar and the differential diagnosis is performed by the histopathology exam, but conservative treatment such as enucleation and curettage can be applied to both... (AU)

Mioepitelioma de vagina: neoplasia poco frecuente en esta localización, reporte de un caso / Myoepithelioma located in the vagina of a pregnant woman

Antecedentes: Los mioepiteliomas, son tumores poco frecuentes originados a partir de la proliferación de células mioepiteliales. La mayor parte localizados en las extremidades inferiores y en glándulas salivales. Existen ocasionales informes previos de MEP que involucren la vagina. Objetivo: Describir un caso de mioepitelioma localizado en vagina. Caso clínico: Embarazada de 29 años edad, quien presenta una masa vaginal de un año de evolución, localizada en el himen. El examen histopatológico muestra una lesión compuesta por células fusiformes con positividad inmunohistoquímica para vimentina, citoqueratinas (CK) AE1/ AE3, S100, CD10, receptores de estrógenos y progesterona, Bcl2 y calponina y negatividad para desmina, actina muscular especifica, actina de músculo liso y p63. Con los anteriores hallazgos se interpreta la lesión como un mioepitelioma primario vaginal. Conclusión: Los mioepiteliomas son tumores que requieren para su diagnostico, análisis con técnicas de inmunohistoquímica o ultraestructurales que permitan diferenciarlos de otros tumores.

Background: The myoepitheliomas are rare tumors arising from the proliferation of myoepithelial cells. Most tumors are located in the lower extremity and salivary glands. There have been only occasional myoepithelial neoplasms previously reported involving the vagina. Objective: Describe a case of myoepithelioma located in the vagina of a pregnant woman. Case report: A 29 years old pregnant female, who about 1 year prior has a vaginal mass, located in the hymen. At histopathological examination shows a mass composed of spindle cells with positivity immunohistochemical studies for vimentin, cytokeratin AE1/AE3, S100, CD10 and calponin and negative for desmin, actinmuscle specific (HHF35), smooth muscle actin and p63. With these findings it was established the diagnosis of myoepithelioma in the vagina. Conclusion: Myoepitheliomas are tumors requiring for diagnostic of immunohistochemistry or ultrastructural techniques that allow its differentiation from other tumors.

Low-grade malignant myoepithelioma arising in a pleomorphic adenoma: a rare case

Malignant myoepithelioma is a very rare salivary gland tumor that can arise de novo or within a preexisting pleomorphic adenoma. We report a case of malignant myoepithelioma most probably arising in a pre-existing pleomorphic adenoma of the left parotid gland. The patient was a 60-year-old man who presented with a multinodular mass lesion over left side of the face and neck. He had undergone removal of a pleomorphic adenoma of the left parotid gland twice [8 and 22 years ago]. Histological examination showed locally concentrated highly invasive myoepithelial cells with bland-looking morphology and no evidence of mitosis or necrosis. Immunohistochemistry confirmed the myoepithelial differentiation [S-100+, SMA+] and a low Ki-67 labeling index [<5%]

Mioepitelioma intraóseo: presentación de un caso y revisión de la literatura / Intraosseous myoepithelioma: report of a case and review of the literature

Durante su formación, remanentes de glándulas salivales pueden quedarse atrapados en diversas partes del cuerpo, incluyendo el maxilar y la mandíbula. Lo siguiente da lugar a proliferaciones neoplásicas de carácter benigno y maligno. El mioepitelioma es una rara neoplasia de glándulas salivales, cuya frecuencia es poco frecuente. Representa aproximadamente el 1.5 por ciento de todos los tumores de glándulas salivales, mayores y menores. Es aún más infrecuente su localización intraósea, siendo reportados en la literatura menos de veinte casos en esta localización. En este artículo se presenta un caso de mioepitelioma, variante epitelioide, de localización intraósea. El mismo fue tratado mediante maxilectomía de infraestructura con márgenes libres de lesión, obteniendo finalmente buenos resultados estéticos y funcionales.

Adenomioepitelioma de la mama: reporte de un caso / Adenomyoepithelioma of the breast: a case report

El adenomioepitelioma es un infrecuente tumor de la mama, conformado por una proliferación bifásica de células epiteliales y mioepiteliales. Presentamos las características clínicas y morfológicas de un caso de adenomioepitelioma benigno diagnosticado en una paciente de 34 años en la Unidad de Anatomía Patológica del Hospital Hernán Henríquez Aravena de Temuco.

Breast adenomyoepithelioma is a rare tumor, characterized bythe biphasic proliferation of epithelial and myoepithelial cells. We present clinical and morphological features of a case of benign adenomyoepithelioma diagnosed in a 34 year old patient in the Hernán Henríquez Aravena Hospital in Temuco.

Carcinoma sebáceo/mioepitelial de parótida: análisis histopatológico e inmunohistoquímico / Sebaceous epithelial myoepithelial carcinoma of parotid: histopathological and immunohistochemical analysis

El carcinoma epitelial-mioepitelial (CEM) de glándulas salivales es un tumor maligno bifásico de bajo grado, que comprende aproximadamente el 1 por ciento de todos los tumores salivales. Se describe un raro caso de CEM sebáceo de glándula parótida en un hombre al que se le realizó parotidectomía izquierda por formación tumoral aparentemente encapsulada. Para su estudio histopatológico e inmunohistoquímico el material se coloreó con H/E, tricrómicos de Massony Dane/Azul alciano, PAS/H, Azul de toluidina, antígeno epitelial de membrana (EMA), citoqueratinas (CK) de bajo peso molecular, a actina de músculo liso (a-SMA) y S-100. Los cortes histológicos mostraron un patrón multinodular con nidos tumorales constituidos por estructuras tubulares delimitadas por: a-células acidófilas luminales cuboideas; b- células claras adluminales. Las células ductales luminales se marcaron positivamente con los anticuerpos para EMA y CK. Se observó inmunorreactividad positiva para a-SMA y S-100 en las células claras. Se observaron áreas de diferenciación sebácea dentro de la masa tumoral. Los estudios inmunohistoquímicos confirman la presencia de células tumorales ductales y mioepiteliales. Además, las células claras mioepiteliales constituyen un elemento importante para el diagnóstico diferencial entre CEM sebáceo y adenocarcinoma sebáceo.

Epithelial myoepithelial carcinoma (EMC) of the salivary glands is an uncommon, low grade, biphasic neoplasm. We reported a rare case of sebaceous EMC of the parotid gland in a man who had a left parotidectomy because of a tumoral formation apparently encapsulated. For the histopathological and immunohistochemical study the material was stained with H/E, Masson and Dane/Alcian blue trichrome, PAS/H, Toluidine blue, epithelial membrane antigen (EMA), cytokeratins (CK) of low molecular weight, a-smooth muscle actin (a-SMA) and S-100. Histologically, the tumor showed a multinodal pattern with tumoral nests constituted by ducts with a double cell lining: a- luminal cuboidal eosinophilic cells; badluminalclear cells. The inner cells were positively marked with antibodies for EMA and CK. It was observed positiveimmunoreactivity for a-SMA and S-100 in clear cells. It was observed areas of sebaceous differentiation inside the tumoral mass. Immunohistochemical studies confirmed ductal tumoral and myoepithelial cells presence. Besides, myoepithelial clear cells aided differential diagnosis between sebaceous EMC and sebaceous adenocarcinoma.

Myoepithelioma of soft tissue.

Myoepitheliomas and mixed tumors involving deep subcutaneous and subfascial soft tissues of limb or limb girdle are rare lesions as against salivary lesions that are well established conditions. Here, we report a 22-year-old female who presented with painful hard swelling in the left gluteal region of 1(1/2) year duration. MRI showed a large ill-defined heterogeneous mass lesion measuring about 7-8 cm. in the left sacral region eroding the left sacroiliac region and left sacroiliac joint. With a clinical diagnosis of chondrosarcoma, the tumor with the surrounding tissue was resected in segments at surgery. Histomorphology revealed nests, sheets and cords of round to spindled cells with extensive squamous metaplasia in a myxoid to fibrous stroma. These cells extensively infiltrated muscle and bone. The tumor cells expressed immunoreactivity for cytokeratin (AE1/AE3) and S-100.

Malignant Myoepithelioma of the Palate: A Case Report with Review of the Clinicopathological Characteristics

A malignant myoepithelioma is one of the rarest salivary gland neoplasms which may either arise de novo or develop within a preexisting pleomorphic adenoma or benign myoepithelioma. The parotid gland is the most common primary site and the palate the most common intra-oral site of occurrence. Herein is present a case of a malignant myoepithelioma arising in the hard palate of a 79-year-old woman. The lesion had been examined by biopsy at another hospital, and diagnosed as a poorly differentiated squamous cell carcinoma. The patient underwent a wide local tumor resection. Examination of the resection specimen showed the characteristic histopathological and immunohistochemical features of a malignant myoepithelioma. Five months after the operation, the patient was well without evidence of recurrence or metastasis.

Myoepithelial carcinoma of soft tissue: a case report.

Myoepithelioma of soft tissue is a recently categorized entity and myoepithelial carcinoma is extremely rare. We describe a case of myoepithelial carcinoma of soft tissue in a 30-year-old male patient, who presented with a painless mass located at the back of left leg involving popliteal fossa that was present since childhood. A wide local excision was performed. The distinct histopathological features included infiltrative margins, cytologically moderate to severely atypical epithelioid/spindled cells with prominent nucleoli, 3-4 mitoses/10HPF, tumor necrosis and lymphovascular invasion. No heterologous elements were identified. The myoepithelial origin was confirmed by positive immunohistochemical staining for S100 protein, epithelial membrane antigen and smooth muscle actin. Mib-1 (Ki-67) proliferation index was 20-25%. These carcinomas have variable clinical presentation and can have an indolent course for several years. Recognition of myoepithelial carcinoma is clinically significant because compared to its benign counterpart, this has increased frequency of local recurrences and metastases that warrants a close clinical follow-up.

Myoepitheliomas of the Soft Palate: Helical CT Findings in Two Patients

We describe the enhancement patterns of myoepithelioma in two patients with a soft palate mass. In the first case, helical CT revealed a faintly enhancing mass. Histologically, the tumor was composed of plasmacytoid cells in a background of rich myxoid stroma. Immunostaining for CD34 showed scanty blood vessels. In the second case, helical CT revealed an intensely enhancing mass. Histologically, the mass was a cellular tumor with fibrous stroma. Immunostaining for CD34 also showed frequent blood vessels.

Epithelial myoepitheial carcinoma of minor salivary gland--low grade malignant tumor presenting with nodal metastasis.

Epithelial myoepithelial carcinoma (EMC) is a rare low grade malignant salivary gland neoplasm that most commonly occurs in the parotid gland but can also arise in minor salivary glands. We report a case of primary epithelial myoepithelial carcinoma of minor salivary gland in a 25 year old women who presented with swelling left cheek of one year duration and bilateral submandibular lymphadenopathy. A mass causing erosion of mandible, thyroid cartilage and masseter muscle was identified on CT scan. This was excised and histological examination revealed a mixture of ductal structures consisting of inner dark cells and outer clear cells seen in solid sheets. Immunohistochemical analysis showed the clear cells to be weakly positive for S100 and smooth muscle actin (SMA) and ductal cells to be positive for cytokeratin (CK) and epithelial membrane antigen (EMA). The characteristic morphological and immunohistochemical features aided in the diagnosis of epithelial myoepithelial carcinoma.

Pure malignant myoepitheliomas of the breast: an immunohistochemical study.

Myoepithelioma of breast are extremely rare. We report two cases of pure malignant myoepithelioma of the breast, utilising light microscopic and immunohistochemical methods for diagnosis. Both the cases presented as breast lump. Hematoxylin and Eosin (H&E) stained microscopic sections revealed a predominantly spindle cell tumor. Immunohistochemical work up was done. Case number one expressed positivity for vimentin, Smooth Muscle Actin (SMA), S-100 and CD10. Case number two expressed positivity for Vimentin, CD10 and p63. This led to the diagnoses of malignant myoepithelioma in both of them. Documentation of such cases prospectively and from archival material, using immunohistochemistry, is of extreme importance to assess the prevalence, various phenotypic patterns, long-term biological behaviour and to establish management protocols for malignant myoepithelioma.

Adenomyoepithelioma of the breast: a potential diagnostic pitfall on fine needle aspiration cytology.

Adenomyoepithelioma is a rare myoepithelial cell-rich tumour of the breast. We report a case of adenomyoepithelioma in a 60-year-old female, where it evoked the suspicion of a carcinoma on fine needle aspiration cytology (FNAC) smears and also review the literature on FNAC diagnosis of this rare tumour.

Plasmacytoid variant of myoepithelioma of palate: a case report.

Myoepitheliomas of intraoral minor salivary glands are rare and are usually of plasmacytoid type. Myoepitheliomas are considered difficult to diagnose without the aid of ultrastructural and histochemical studies. Here we present a case report of plasmacytoid type of myoepithelioma of palate that was diagnosed by light microscopic examination alone. Considering the non-specificity of ultrastructural and histochemical findings, it is important to pay attention to typical features of plasmacytoid myoepitheliomas to arrive at a diagnosis.

Radiologic-Pathologic Correlation of Unusual Lingual Masses:Part II: Benign and Malignant Tumors

Because the tongue is superficially located and the initial manifestation of most diseases occurring there is mucosal change, lingual lesionscan be easily accessed and diagnosed without imaging analysis. Some lingual neoplasms, however, may manifest as a submucosal bulge and be located in a deep portion of the tongue, such as its base; their true characteristics and extent may be rec-ognized only on cross-sectional images such as those obtained by CT or MRI. Some uncommon tongue neoplasms may have characteristic radiologic fea-tures, thus permitting quite specific radiologic diagnosis. Lipomas typically manifest at both CT and MR imaging as homogeneous nonenhancing lesions. Relative to subcutaneous fat they are isoattenuating on CT images, and all MR sequences show them as isointense. Due to the paramagnetic properties of melanin, metastases from melanotic melanoma usually demonstrate high signal intensity on T1-weighted MR images and low signal intensity on T2-weighted images. Although the radiologic findings for other submucosal neoplasms are nonspecific, CT and MR imaging can play an important role in the diagnostic work-up of these unusual tumors. Delineation of the extent of the tumor, and recognition and understanding of the spectrum of imaging and the pathologic features of these lesions, often help narrow the differential diagnosis.

Análise da citodiferenciaçäo de linhagens celulares derivadas de adenoma pleomórfico e de mioepitelioma humanos de glândulas salivares: estudo comparativo dos elementos citoesqueléticos e da resposta dessas células à membrana basal reconstituída (Matrigel) / Cytodifferentiation analysis of cell lines derived from human pleomorphic adenoma and human myoepithelioma: a comparative study based on the expression of cytoskeletal components and on the response of these two cell lines to a reconstituted basement

Adenoma pleomórfico e mioepitelioma säo neoplasias de glândulas salivares que exibem aspectos clínicos e histológicos semelhantes. Para avaliar o estágio de diferenciaçäo das células de maior capacidade proliferativa dessas neoplasias, utilizamos linhagens celulares derivadas de adenoma pleomórfico (AP2) e de mioepitelioma (M1). Estudamos a expressäo de proteínas citoesqueléticas, os aspectos subcelulares e a resposta das linhagens à membrana basal reconstituída (Matrigel). Células AP2 mostraram imunomarcaçäo a vimentina e citoqueratina 14, enquanto que células M1 a vimentina, pan-queratina e actina de músculo liso. Estudo subcelular da linhagem AP2 revelou características de células pouco diferenciadas. Célula M1 mostraram aspectos subcelulares de fenótipo mioepitelial bem diferenciado, exibindo feixes de microfilamentos com adensamentos focais. Após uma semana envolvidas por Matrigel, células AP2 exibiram formaçäo de estruturas ductiformes e células M1 organizaram-se em cordöes celulares. Nossos resultados indicam que células AP2 exibem fenótipo epitelial glandular neoplásico pouco diferenciado, enquanto que células M1, fenótipo mioepitelial neoplásico bem diferenciado. Admitindo-se que o adenoma pleomórfico e o mioepitelioma resultem de proliferaçäo neoplástica de células do ducto intercalado de glândulas salivares, o adenoma pleomórfico originar-se-ia de células mais indiferenciadas e permissivas, enquanto que células já comprometidas com a diferenciaçäo no sentido mioepitelial dariam origem ao mioepitelioma