Primary Small Cell Anaplastic Carcinoma of the Breast Diagnosed by Fine Needle Aspiration Cytology: A Case Report.

BACKGROUND: Small cell anaplastic carcinoma most commonly presents as a lesion in the central portion of the lung but occasionally is found in peripheral locations. Only seven cases originating in the breast have been described. To our knowledge, the preoperative diagnosis of this entity by fine needle aspiration has not been previously reported in the cytologic literature. CASE: A 67-year-old female presented with a 4 x 3-cm, rapidly growing mass in the left breast. On fine needle aspiration (FNA) the tumor was soft to the needle and yielded a highly cellular aspirate. CONCLUSION: In this case the morphologic interpretation of FNA, combined with the immunocytochemical demonstration of neuron-specific enolase in tumor cells, was extremely helpful in establishing the nature of the breast tumor