Eccrine spiradenoma: analysis of the clinical and pathological features of 7 patients.

The purpose of this study was to explore the clinical, pathological, and immunohistochemical features of spiradenoma. The clinical and pathological data of seven patients were analyzed. The analysis revealed that the median age of onset was 34 years, with three patients presenting lesions on the extremities. Clinically, the lesions were mostly skin-colored or red subcutaneous nodules or masses, some of which were tender. Histopathological features included well-demarcated tumor masses composed of two types of cells: small cells with round, deeply stained nuclei and larger cells with lightly stained nuclei, accompanied by ductal differentiation and focal adenoid cystic structures. Lymphomonocytic infiltration was observed in the stroma. Immunohistochemical staining revealed positive expression of cytokeratin (CK) and cluster of differentiation 117 (CD117) in luminal cells and tumor protein p63 (p63) and smooth muscle actin (SMA) in outer myoepithelial cells. SRY-related HMG-box 10 (Sox10) expression was typically diffuse positive. Spiradenoma is a sweat gland tumor for which clinical specificity is lacking, but these nodules have distinct histopathological features. In most cases, a definitive diagnosis can be made with the aid of immunohistochemistry.