Fig. 6

Immunophenotype of small cell-like change in intraductal carcinoma. Absent expression of PSA (A: PSA, 100x) and absent expression of chromogranin (B: chromogranin, 100x). Synaptophysin expression was not observed in small cell-like change in intraductal carcinoma, however, focal expression was observed in usual acinar adenocarcinoma in the vicinity (C: Synaptophysin, 100x). CD56 expression was not observed in small cell-like change in intraductal carcinoma, however, scattered cells were positive in usual acinar adenocarcinoma in the vicinity (D: CD56, 400x). Ki67-positive cells are easily seen in the periphery of intraductal carcinoma, but no expression was detected in small cell-like areas (E and F: Ki67, 400x)