Medullary breast carcinoma: a case report with cytological features and histological confirmation.

We report the case of a 83-year-old woman who presented with a left-breast lump. On physical examination the patient had a well-demarcated mass located in the upper outer quadrant of her left breast with a palpable unilateral axillary lymph node. Mammography and ultrasonography depicted a heterogeneous well-defined lesion measuring 6 cm in diameter without calcifications. Fine-needle aspiration cytology of the lesion was performed. Cytological examination revealed highly cellular smears containing large atypical cells arranged in syncytial sheets and intimately admixed with lymphocytes and neutrophils. The nuclear to cytoplasmic ratio was high in tumor cells whose nucleus exhibited coarse chromatin with one or more conspicuous nucleoli. The diagnosis of medullary breast carcinoma, which was strongly suspected by cytology, was confirmed by histological examination of the surgical specimen after a modified radical mastectomy with axillary dissection.