Alopecia attributed to neoplastic ovarian tissue in two ferrets.

Ferrets with adrenal gland dysfunction have alopecia as their most common clinical sign of disease. Two cases of alopecia in neutered female ferrets are reported that were associated instead with neoplastic tissue found at the site of an ovarian pedicle. Androstenedione and 17-hydroxyprogesterone, but not estradiol, concentrations were high in both ferrets. Following surgical resection of the abnormal tissue in one ferret, the high hormone values decreased quickly and hair regrowth ensued. In both cases, histologic examination revealed features consistent with classical sex cord-stromal (gonadostromal) tumors: prominent spindle cells, along with polyhedral epithelial cells and cells with vacuolated cytoplasm. Although similiar cell types have been described in the adrenal glands of ferrets with adrenal-associated endocrinopathy, an ovarian origin for the current neoplasms is considered likely on the basis of their anatomic location; accessory adrenal tissue has only been described close to an adrenal gland or in the cranial perirenal fat of ferrets. Immunohistochemical analysis, using an antibody against Mullerian-inhibiting substance, failed to prove definitively the source of the steroidogenic cells.