Soft tissue myoepithelial carcinoma of neck: A rare case report with review of literature

Primary soft tissue myoepithelial tumor, an uncommon variant of myoepithelial neoplasms, has been recently described in reviewed literature. We report a rare case of soft tissue myoepithelial carcinoma in a 60 year old male patient presented as a unilateral neck mass. MRI showed a large lobulated infiltrating heterointense mass with central necrotic area involving left parapharyngeal space. Histopathological examination revealed multilobular growth pattern of epitheloid cells with marked atypia and frequent mitosis. Immunohistochemistry was reactive for p63, calponin, CD10, pancytokeratin, EMA and podoplanin with high (40%) proliferative labeling index. Except for the presence of increased malignant cell population, soft tissue myoepithelial carcinoma mimics their salivary gland counterpart in clinical and biologic behavior. Rarity in head and neck region (only 16%) and heterogeneity in cellular morphology and architectural patterns, may lead to misdiagnosis of extraglandular myoepithelial carcinoma. So, careful and meticulous observation of both histopathologic and immunophenotypic features are essential for correct diagnosis of such entities.