Eccrine Spiradenoma: Pathologic Analysis of 9 Cases

ABSTRACT

The clinicopathology of nine cases of eccrine spiradenoma was examined. The ages of the patients ranged from 32 to 65 years, with an average age of 46 years. There were four males and five females. Eight tumors out of the nine presented on the ventral surface of the upper body. The tumors were solitary in seven cases and multiple in two cases(cases 8 and 9). Six tumors were either painful or tender to palpation. Histologically, two cases(cases 1 and 2) were adenomas with well developed tubular structures, while the remaining seven cases were epitheliomas with poor organization and prominent reticular pattern. All tumors were composed of two distinct cell types. Since four cases showed considerable edema with a lot of cystic change, it was difficult in some areas to differentiate these from other adnexal tumors or vascular tumors. Immunohistochemical staining was performed on paraffin-embedded sections of 5 eccrine spiradenomas. CEA and EMA were expressed in the cytoplasm of tumor cells in all cases. Cytokeratin was expressed in 4 out of 5 cases, and S-100 in 3 out of 5 cases. There has been no evidence of recurrence in 8 cases. In one case(case 9) the tumor recurred locally with carcinomatous transformation- characterized by the presence of solid areas of tumor which was composed of large cells with irregularly shaped nuclei and mitotic figures. There were foci of ductal differentiation, extensive areas of tumor necrosis and invasion into surrounding connective tissue. The carcinomatous portion revealed positive reaction for CEA, EMA, S-100 protein and cytokeratin.