Fine needle aspiration cytology from a cystic breast lump

摘要

The patient was a 30-year-old woman who had regular periods and was nulliparous. She was admitted to Kato Breast Surgery Clinic in December 2005 complaining of a painless lump increasing in size in the left breast. Physical examination revealed a tumour, measuring 3.0 x 4.0 cm, in the upper outer quadrant of the left breast. There were no palpable lymph nodes. Sonographic findings showed an echo-genie solid component in the cystic space with ill-defined edges. Mammographs showed an ill-defined mass rated category 4 using Breast Imaging Reporting and Data System assessment categories. The aspirate produced yellowish-coloured viscous fluid. Pre-opera-tive fine needle aspiration (FNA) cytology yielded abundant tumour cells that were smeared onto several slides.Metaplastic breast carcinoma (MBC) is a very rare neoplasm accounting for <1% of all breast malignancies.1 This neoplasm is a heterogeneous group of breast malignancies characterized by the admixture of ductal carcinoma with extensive squamous differentiation and/or spindle cell proliferation with or without chondroid or osseous heterogeneous elements. Usually, MBC has a biphasic growth pattern, with both carcinomatous and mesenchymal components and has thus previously been called 'malignant mixed tumour of the breast', and 'carcinosarcoma'. However a recent study has shown that most MBC represent tumour with a myoepithelial cell histogenesis.