Mucinous hidradenoma: a report of three cases.

Mucinous cutaneous adnexal tumors are an uncommon occurrence. We describe three cases of mucinous hidradenoma characterized by diffuse and prominent mucinous cell proliferation and discuss the relevant literature. The patients (two men and one woman) ranged in age from 32 to 72 years. The lesions were completely excised, and all patients were alive without evidence of disease (follow-up interval 3-4 years). Case 1 presented as a 1.3-cm eyelid nodule and histology showed a mucinous apocrine hidradenoma with a proliferation of mucinous cells and apocrine glands. Case 2, from the shoulder of a 40-year-old man, was a 2.5-cm well-circumscribed nodule composed of hyperplastic villoglandular proliferation of mucinous cells with focal squamous whorls and focal columnar glandular cells showing decapitation secretion. The tumor was also interpretated as a mucinous hidradenoma, most likely of follicular-apocrine origin. Case 3 was a 3.0-cm scalp nodule. The histology showed a mucinous clear-cell hidradenoma composed of numerous mucinous glands amidst small squamous cells with clear cytoplasm and a hyalinized fibrovascular stroma.