Cell proliferation in skin tumors with ductal differentiation: patterns and diagnostic applications

<p>The kinetic features of skin tumors with ductal differentiation (TDD) remain mainly unknown. We selected 88 skin TDD (D-PAS-positive cuticles) classified according to Murphy and Elder's criteria. Tumors studied included 13 poromas, 12 nodular hidradenomas, 10 cylindromas, 6 spiradenomas, 9 syringomas, 9 chondroid syringomas, 7 porocarcinomas, 15 malignant nodular hidradenomas, and 7 not otherwise specified carcinomas. The same tumor areas were evaluated for mitotic figure counting (MFC) and proliferation rate (PR = MIB-1 index), screening 10 consecutive high-power fields (HPFs) in the most cellular areas. Results were recorded by HPF and tumor cellularity, considering both average and standard deviation. Differences were analyzed by Student's t-test and analysis of variance (ANOVA) and considered significant if p</p>