Soft tissue myoepithelial carcinoma: is it a low-grade cancer? / Carcinoma mioepitelial de partes moles: um tumor de baixo grau de malignidade?

ABSTRACT Myoepithelial carcinoma is a rare neoplasm of very heterogeneous manifestation that represents a major challenge to the adoption of categorical prognostic criteria since, despite being classified as a low-grade cancer, it behaves very aggressively. While several studies have indicated complete surgical resection as the best treatment for myoepithelial carcinoma, adjuvant therapies have proven effective in preventing relapse. This study describes the case of a patient who developed myoepithelial carcinoma in the right thigh, affecting deep tissues, which were conducted as indicated in the current literature, however, presenting an unfavorable outcome. The available information comes from few studies; therefore, we emphasize the importance of gathering data on the subject, which are still scarce.

RESUMEN El carcinoma mioepitelial es una neoplasia rara, de manifestación muy heterogénea, que encierra un gran desafío para la adopción de criterios pronósticos categóricos, puesto que, a pesar de ser clasificado como tumor de bajo grado de malignidad, muestra comportamientos muy agresivos. Mientras varios estudios indican la resección quirúrgica completa como el mejor tratamiento para el carcinoma mioepitelial, terapias adyuvantes se han revelado efectivas para prevenir la recidiva. Este estudio describe el caso de una mujer que presentó carcinoma mioepitelial en muslo derecho, afectando partes profundas, lo cual fue conducido como indica la literatura actual, sin embargo, con un resultado desfavorable. Las informaciones disponibles son producto de pocos estudios, por ello, destacamos la importancia de reunir datos acerca del tema, que aún son escasos.

RESUMO O carcinoma mioepitelial é uma neoplasia rara, de manifestação muito heterogênea, que encerra um grande desafio na adoção de critérios prognósticos categóricos, uma vez que, apesar de ser classificado como tumor de baixo grau de malignidade, apresenta comportamentos muito agressivos. Enquanto vários estudos indicam a ressecção cirúrgica completa como o melhor tratamento para carcinoma mioepitelial, terapias adjuvantes têm-se revelado efetivas na prevenção da recidiva. Este estudo descreve o caso de uma paciente que desenvolveu carcinoma mioepitelial em coxa direita, acometendo partes profundas, o qual foi conduzido como indica a literatura atual, contudo, apresentando desfecho desfavorável. As informações disponíveis provêm de poucos estudos, logo, ressaltamos a importância de reunir dados a respeito do tema, que ainda são escassos.

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)

CT performances and literature review of myoepithelioma of the parotid gland / 实用放射学杂志

Objective To study the CT performances and literature review of myoepithelioma (ME)of the parotid gland,to improve the recognition and diagnostic accuracy of this disease.Methods The CT findings of 1 2 cases with ME of the parotid gland confirmed by surgery and pathology were analyzed retrospectively,the characteristics of the age of onset,gender,size,location,density,boundary and enhancement were analyzed.And then,the related literatures were reviewed.Results Among the 1 2 patients,5 were male and 7 were female,age ranged from 11 to 68 years old,with a median age of 45.2 years.2 patients had the symptom of tenderness and fever, and the other 10 patients were asymptomatic and painless preauricular mass,2 of which were gradually enlarged.All the tumors were single in this study,2 had visible capsule infiltration or unclear boundaries,and other 10 had intact or smooth edges.CT showed that the masses all located in the parotid gland(1 in the deep lobe and 11 in the superficial lobe).The diameter of the tumor was 10 mm to 50 mm,with an average of 29.1 mm.The density was uniform in 2 cases and irregular cystic degeneration and necrosis in the other 10 cases.Mild enhancement was found in the arteriovenous phase after enhanced scanning,in which 8 cases had marginal enhancement or nodular enhancement in the arterial phase,and gradual filling into the center in the venous phase.Conclusion The CT performances of ME of the parotid gland have define characteristics.The possibility of myoepithelioma of the parotid gland should be taken into account when it has continuous centripetal reinforcement after enhancement,combing with the single cystic solid mass with clear boundary in superficial lobe of the parotid gland.Malignant myoepithelioma (MM)should be considered when the tumor envelope is incomplete or the boundary with the surrounding structure is not clear.

Spindle cell myoepithelioma of the parotid gland

Myoepithelioma was recognized as a histological distinct entity by the World Health Organization (WHO) in 1991. Myoepithelial cells are believed to be of ectodermal origin. In salivary glands, the myoepithelial cells that surround the intercalated ducts are spindled, which is in contrast to the large stellate ones that envelop the acini. Myoepithelioma is a benign salivary gland tumor that consists entirely of myoepithelial cells. A 53-year-old man presented with a 1-year history of a painless mass originating from the right parotid gland. The mass grew rapidly reaching a size of approximately 6 cm. The patient had no facial paralysis. The authors performed right parotidectomy. Immunohistochemistry study of this tumor showed that it was positive for vimentin, positive for S-100, focally positive for pancytokeratin, and focally positive for p63 and that it had a Ki-67 labeling index (below 10%). Additionally, the tumor was negative for epithelial membrane antigen, negative for actin, negative for desmin, negative for CD34 and negative for anaplastic lymphoma kinase. The authors present a case of benign spindle cell myoepithelioma of the parotid gland in a 53-year-old man diagnosed after immunohistochemistry study, describing its importance, along with a brief review of the literature.

Clinicopathologic and molecular features of myoepithelial tumors of salivary glands / 中华病理学杂志

Objective@#To investigate the clinicopathological, and molecular characteristics of myoepithelial tumors (MTs) of salivary glands.@*Methods@#A total of 37 MTs cases including 13 malignant epithelial tumors (MMTs) and 24 benign epithelial tumors (BMTs) of salivary glands were identified from the archives of the Department of Pathology, General Hospital of Eastern Theater Command, dating from 2006 to 2016. Clinical features, histological patterns, immunohistochemical characteristics and status of EWSR1 gene rearrangement by fluorescence in situ hybridization (FISH) analysis were reviewed in all cases.@*Results@#Clinically, 37 MTs cases mainly occurred in the parotid glands, when most of the patients presented with painless masses. Of the 13 MMTs cases, male to female ratio was 7∶6, and the median age was 62 years old. Of the 24 BMTs cases, male to female ratio was 5∶7, and the median age was 54 years old. Immunohistochemically, 37 MTs cases were positive for CKpan, and at least one myoepithelial marker. Twenty six of 37 MTs cases were analyzable for the EWSR1 gene break by FISH. Based on the previous evaluation criterion, the EWSR1 translocation was detected in 4 cases of 11 MMTs, and 4 cases of 15 BMTs. According to the main histological composition of tumor cells, 4 EWSR1-positive MMTs covered 2 clear-cell cases and 2 epithelioid-cell cases, when 4 EWSR1-positive BMTs covered 2 clear-cell cases, 1 plasmacytoid-cell case, and 1 spindle-cell case.@*Conclusions@#Males and females are affected equally. MTs express immunoreactivity for CKpan, and at least one myoepithelial marker. The EWSR1 rearrangement is present in a subset of MTs, with variable morphological characteristics, and has no statistical significance on clinical behavior.

Myoepithelioma in accessory parotid gland: report of a rare case / Mioepitelioma em glândula parótida acessória: relato de um caso raro

Mioepitelioma é um tumor benigno de glândula salivar que acomete, principalmente, a glândula parótida. Apresença de uma glândula parótida acessória é uma variação anatômica e neoplasias nessa estrutura são extremamente raras. Este artigo descreve um caso de mioepitelioma ocorrendo em uma glândula parótidaacessória de uma mulher de 29 anos de idade. No entendimento dos autores este é o sétimo caso relatado em Inglês. A queixa da paciente era umamassa na bochecha, com cinco anos de evolução, apresentando súbito surto de crescimento. A paciente foi submetida à cirurgia por meio de uma abordagemintra-bucal e a histopatologia e a imunohistoquímica revelaram um mioepitelioma.

Myoepithelioma is a benign tumor of the salivary gland that mainly affects the parotid gland. The presence of an accessory parotid gland is an anatomical variation and neoplasms in this structure are extremely rare. This paper describes a case of a myoepithelioma arising in the accessory parotid gland of a 29-year-old woman. To the author´s knowledge this is the seventh case reported in English. The patient´s complaint was about a five year growing mass in the left cheek with a sudden growth outbreak. The patient underwent surgery via an intra-oral approach and the histopathology and the immunohistochemistry disclosed a myoepithelioma.

CT imaging and pathological features of maxillofacial malignant myoepithelioma / 实用放射学杂志

Objective To evaluate CT imaging and pathological features of maxillofacial malignant myoepithelioma (MME). Methods A total of eight patients with pathologically confirmed MME of the maxillofacial region were underwent non-enhanced and contrast-enhanced CT scans.CT features of the lesions were assessed as follows:location,number,shape,size,enhancement pattern and CT number on non-enhanced and contrast-enhanced scan.CT features were compared with the pathological results.Results All the lesions were unilateral,in which mixed type with clear cells and spindle cells in 5 cases,mixed type with epithelioid cells and plas-ma cells in 2 cases,and clear cell type in one case.8 cases were manifested as lobulated mass.On non-enhanced scan,the density of all the lesions were hetergeneous with cystic area,1 case with calcification and 2 cases with bone destruction.On the contrast-en-hanced CT,all the lesions were showed hetergeneously moderate or obvious enhancement,and cystic,line and crack areas without the enhancement were observed.Minor vessel and spiculate protuberance of marginal zone on the arterial phase were observed in most le-sions.Conclusion MME has different pathological subtypes and characteristic CT features.CT is an effective method to diagnose MME.

Intraosseous myoepithelioma: A rare, distinct tumor entity

Primary musculoskeletal myoepithelial tumors (METs) are distinctly rare tumors and are being increasingly recognized as a result of improved diagnostic criteria and objective confirmation with immunohistochemical markers, including epithelial markers. Recent studies have unraveled distinct molecular mechanisms underlying these tumors. Herein, we present our second diagnosed case of an intraosseous MET that occurred in the tibia of a 37-year-old lady. The case is discussed with regards to current clinicopathological perspectives on these rather uncommon tumors, including our personal experience.

Soft Tissue Malignant Myoepithelioma in the Extremities / 대한골관절종양학회지

PURPOSE: We report the diagnosis, treatment outcomes and prognosis of the patients with soft tissue malignant myoepithelioma in the extremities. MATERIALS AND METHODS: We retrospectively reviewed 6 patients with soft tissue malignant myoepithelioma in the extremities who were treated at our institution between 2008 and 2014. Two patients received unplanned excision at another hospital and remaining 4 patients underwent the biopsy procedures and received wide excision at our hospital. RESULTS: There were 3 men and 3 women with mean age of 41 (33-54) years. The average follow up was 28 (9-45) months. Among the 6 patients, only 4 patients underwent biopsy procedures under the impression of malignant soft tissue sarcoma. Surgical margins for these 4 patients were negative. Two patients who had unplanned excision received another re-excision and one of them showed no residual tumor in the resected specimen. Local recurrences were developed in all patients and distant metastasis in 4 patients. All 4 patients who developed distant metastasis died due to disease progression. Among the 2 patients who developed local recurrence only, one patient has another local recurrence after re-operation and remaining one patient is no evidence of disease for 2 years after resection of locally recurred mass. CONCLUSION: Soft tissue malignant myoepithelioma in the extremities is a rare disease and shows an aggressive behavior. Appropriate biopsy under the impression of soft tissue malignancy is necessary and complete surgical resection with wide margins is the recommended treatment of choice.

Recurrent Benign Myoepithelioma of the Auricle

Myoepithelioma, a generally benign tumor comprised of myoepithlial cells, is an uncommon salivary gland tumor. Myoepithelioma originates primarily in the parotid gland, but several isolated cases have been described. Although myoepithelioma has a benign nature, but there is a potential risk of malignant change and recurrence in case of incomplete resection. We acknowledge that benign myoepithelioma originating from the auricle has not been reported in the English literature. We present a rare case of 27-year-old female who had recurrent benign myoepithelioma originating from the auricle and already had been given twice operations at the other clinic.

Imprint Cytology of Soft Tissue Myoepithelioma: A Case Study

Soft tissue myoepithelioma is a rare neoplasm composed of myoepithelial cells. Here, we describe the cytologic features of soft tissue myoepithelioma arising on the right forearm in an 18-year-old man. The excised tumor (3.0x1.8x1.5 cm) was well-demarcated, yellow-gray, soft, and myxoid. The cytologic smears showed round to spindle, epithelioid, and plasmacytoid cells in the myxoid background. The nuclei were uniform, round to ovoid, with finely distributed chromatin and eosinophilic or pale cytoplasm. The tumor cells demonstrated immunoreactivity for cytokeratin (AE1/AE3), epithelial membrane antigen, S100 protein, and glial fibrillary acidic protein. Electron microscopy showed intermediate filaments, desmosomes, and basal lamina.

Ectomesenchymal chondromyxoid tumor of tongue.

Ectomesenchymal chondromyxoid tumor (ECMT) is a rare entity of the dorsal tongue first described in 1995. Herein, we report a rare case of lingual ECMT in a 41-year-old man. Patient presented with an asymptomatic, small nodule (0.5 cm in diameter) in the anterior tongue. The pathological findings showed uni-lobular proliferation of fusiform cells, arranged in net-like sheets or swirls, in a chondromyxoid background. The tumor cells were immunoreactive for S-100 and glial fibrillary acidic protein (GFAP), but negative for epithelial markers. Familiarity with this entity helps pathologists make a correct diagnosis.

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.

Malignant myoepithelioma of the breast: case report with review of literature

Myoepithelial lesions of the breast are extremely rare and can present with a diverse morphology. We report a case of malignant myoepithelioma characterized by proliferation of atypical oval to polygonal cells expressing typical myoepithelial markers. A 45-year-old lady presented with a mass in the left breast. Fine needle aspiration yielded a cellular smear with large papillae-like clusters of monomorphic cells with naked nuclei in the background. A diagnosis of sub-areolar sclerosing duct hyperplasia was made on cytology and the patient underwent excision. The surgical specimen showed a grey-white 5x3 cm mass on cut surface. Histopathology revealed mitotically active (5-6 per 10hpf) oval to polygonal cells tumor cells with clear to eosinophilic cytoplasm arranged in the form of nodules separated by dense sclerotic stroma mimicking clear cell or adenoid-cystic carcinoma. A diagnosis of malignant myoepithelioma was made as the cells were CK14 and SMA positive, and negative for ER and PR on immunohistochemistry. We discuss the unusual morphological features of malignant myoepithelioma, cytological fi ndings and the important differential diagnoses of malignant myoepthelial lesions. A high degree of suspicion with a keen eye for morphological details coupled with relevant immunohistochemistry will aid in arriving at the diagnosis.

Primary Myoepithelioma of the Testis: A Case Report

Myoepitheliomas are well-established to occur in the salivary glands, but they have also been described in the breast, upper aerodigestive tract, skin, and soft tissues. We report here on a unique case of primary myoepithelioma that occurred in the right testis of a 28-year-old man. The tumor was entirely confined to the testis and it was clearly separated from the epididymis. Histopathology revealed mixed architectural patterns in which the reticular areas merged into the chondromyxoid stroma. The tumor cells, which were focally immunoreactive to pancytokeratin and S-100 protein, were round to ovoid and spindly arranged in cords, strands, and fascicles. They showed mild nuclear pleomorphism, sparse mitotic figures and a low Ki-67 proliferative index. There was no ductal differentiation in the tumor. To the best of our knowledge, there has been only one case report of a primary testicular myoepithelioma in the English medical literature.

Adenomioepitelioma maligno: relato de caso / Malignant adenomyoepithelioma: case report

O adenomioepitelioma é uma neoplasia caracterizada por uma proliferação de células epiteliais e mioepiteliais. Essa lesão pode ser encontrada em glândulas salivares, anexos de pele e, muito raramente, na glândula mamária. O adenomioepitelioma foi descrito pela primeira vez em 1970 e muito poucos casos foram publicados desde então. Nós apresentamos o caso de uma mulher de 32 anos com um tumor de 5 cm localizado no quadrante inferior externo que se estendia para o quadrante central e inferior interno da mama esquerda. A paciente apresentava ainda uma lesão satélite de 2 cm no quadrante superior interno da referida mama. Um linfonodo suspeito foi palpado na axila ipsilateral. A paciente foi classificada como no estádio IIIb do sistema TNM. A mamografia mostrou uma lesão infiltrativa categorizada como BI-RADS 4C. Foi realizada uma core-biopsy e uma biópsia incisional. Os exames histopatológico e imunoistoquímico mostraram tratar-se de um carcinoma adenomioepitelial. A paciente foi, então, submetida à mastectomia radical modificada, e o exame histopatológico confirmou o diagnóstico de carcinoma adenomioepitelial; 38 linfonodos axilares dissecados se apresentavam livres de metástases. Foram realizadas radioterapia e quimioterapia como tratamentos complementares. Como a paciente apresentava receptores hormonais negativos, nenhuma forma de tratamento hormonal complementar foi realizada. A paciente se encontrava viva e sem evidência de doença após 27 meses do diagnóstico.

The adenomioepitelioma is a neoplasm characterized by a proliferation of epithelial and myoepithelial cells. This injury can be found in the salivary glands, skin attachments and very rarely in the mammary gland. The adenomioepitelioma was first described in 1970 and very few cases have been published since then. We present the case of a woman of 32 years with a 5 cm tumor located in the lower outer quadrant extending into the central and lower inner quadrant of left breast. The patient still had a satellite lesion 2 cm in the upper inner quadrant of that breast. One suspect was palpable lymph nodes in the ipsilateral axilla. The patient was classified as stage IIIb in the TNM system. Mammography showed an infiltrative lesion classified as BI-RADS 4C. We performed a biopsy and a core-biopsy. Histopathologic and immunohistochemistry showed that it was a adenomioepitelial carcinoma. The patient then underwent modified radical mastectomy, and histopathology confirmed the diagnosis of carcinoma adenomioepitelial, 38 axillary lymph nodes dissected was presented free of metastases. Radiotherapy and chemotherapy were performed as complementary treatments. As the patient had hormone receptor-negative, no further form of hormonal treatment was performed. The patient was alive and without evidence of disease after 27 months of diagnosis.

A Case of Myoepithelial Carcinoma Originated from Inferior Turbinate / 대한이비인후과학회지

Myoepithelial carcinoma is a rare malignant tumor of the salivary glands with an incidence of less than 1%. Most cases arise in the parotid gland but have also been described in the submandibular gland and in the minor salivary glands. Myoepithelial carcinoma shows almost exclusively tumor cells with myoepithelial differentiation, although epithelial-myoepithelial carcinoma is characterized by a biphasic cell population represented by myoepithelial and ductal epithelial cells. Although myoepithelial carcinoma arising in the maxillary sinus has been reported, there is no report of myoepithelial carcinoma that has originated from inferior turbinate. We report, with a review of literature, a 72-year-old female patient diagnosed as myoepithelial carcinoma that has originated from the inferior turbinate of left nasal cavity.

Benign and malignant myoepitheliomas in salivary gland: cases report and immunohistochemical study

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.

Cytology of Plasmacytoid Type Myoepithelioma: Report of Two Cases

Myoepithelioma is a rare benign tumor of salivary gland myoepithelial cells, most commonly as a spindle subtype. Here, we present two cases of fine needle aspiration cytology of plasmacytoid myoepithelioma arising from a parotid gland and a hard palate. Aspirates showed plasmacytoid cells with pink-staining, homogeneous, abundant eosinophilic cytoplasm eccentrically displacing the nucleus in cohesive and dissociated forms. Rarely, nuclear grooves and intranuclear cytoplasmic inclusions were evident. These unfamiliar cytologic findings of uncommon myoepithelioma often cause diagnostic difficulties in preoperative aspiration cytology. Recognition of those rare findings provides a reliable diagnostic clue.