Benign breast myoepithelioma.

Myoepithelioma of the breast is very rare. Breast myoepithelioma can develop in women from their early 20s right up to their 80s, but it is most common in women over 50. We report a case of 20-year-old female, who presented with a well-defined breast lump of 3 × 3 cm in size. Fine needle aspiration was performed. The cytological findings revealed good cellularity comprising monomorphic loosely cohesive sheets of plasmacytoid, round to polygonal cells with round to ovoid eccentrically placed nuclei, finely dispersed chromatin, and moderate amount of cytoplasm. On the basis of cytological findings, a diagnosis of benign myoepithelioma (plasmacytoid type) was made which was confirmed on histopathologic examination. The breast is a very rare localization for this type of tumor. The benign character of the disease in conjunction with its slow progression could delay its detection and diagnosis. A detailed pathology examination is a prerequisite for avoidance of misleading diagnosis.