Blackwell Publishing Journal Backfiles 1879-2005
Background: Nodular Hidradenoma (NH) is an uncommon neoplasm with controversial cell origin (myoepithelial, eccrine and more recently apocrine), and few cytogenetic and DNA flow Cytometry data. Material and Methods: We report a case of NH on the left ankle of a 77 year-old man. The tumor was located subcutaneously and measured 2.5 × 2.0 cm, with no throbbing, tenderness, edema, or groin lymphadenopathy. A wide local excision was performed. Immunohistochemistry using monoclonal antibodies to Smooth Muscle Actin (SMA), S-100 protein, p63 and Calponin were examined. A fresh central portion of the tumor was examined for karyotyping and DNA flow cytometry. Six months later the patient was healthy without local recurrence. Results: The tumor was positive for SMA, Calponin and p63 with focal staining for S-100. The karyotype showed four aberrant, unrelated clones, t(1;8)(p22;p23), del(11)(q14q23), t(1;10)(p13;q22) and del (6)(q23q26). DNA flow cytometry and cell cycle analysis showed that the tumor is 100% diploid with 6.55% S-phase. Conclusions: Expression of SMA, p63, Calponin, and S-100, which are myoepithelial markers, support a myoepithelial origin of this tumor. The multiclonal pattern observed in this neoplasm seems to reflect cytogenetic divergence during neoplastic progression. DNA diploidy with a low S-phase predicts a benign clinical course.
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