2012 Volume 51 Issue 6 Pages 409-414
Background : Invasive micropapillary carcinoma (IMPC) accounts for approximately 3% of all breast cancer cases and is rarely reported in male patients. Our report describes the cytological and histological features of IMPC of the male breast.
Case : A 56-year-old man presented with a hard mass in his right breast. Fine needle aspiration cytology showed many clusters on a clear background. The clusters were of 2 types : clusters with poor connectivity and cohesive papillary clusters. The latter had smooth surfaces and exhibited an “inside-out” pattern with the apical cytoplasm toward the periphery of the clusters. Histologically, the lesion showed a few differences in patterns. The major pattern was typical of IMPC separated by a mesh-like fibrovascular stroma. Minor components such as papillotubullar carcinoma, and scirrhous carcinoma were also observed. The major IMPC component occupied over two-thirds of the lesion, and thus we diagnosed the lesion as IMPC.
Conclusion : IMPC can be distinguished from other types of carcinomas because the clusters exhibit an inside-out pattern with the apical cytoplasm toward the periphery. It is important to clinically suspect IMPC because of its high malignancy.
