Abstract
Focal adnexal dysplasia(FAD) is a rare non-neoplastic lesion of adnexal appendages that occurs in dogs and has good prognosis. We report a case in which FAD diagnosis was favored by its histopathological features. A 8-year-old, castrated male American cocker spaniel dog presented with papillomatous masses on the distal phalanx of left forelimb. Histopathologically, the stroma was sharply demarcated from the adjacent dermis and subcutis. The adnexa was surrounded and interspersed with abundant, hyalinized collagen and the numerous sebaceous lobules distributed haphazardly around hair follicles, which is thickened, dilated and tortuous with abundant keratin. Epidermis was acanthotic. Proliferative lesions of the skin region are very common with similar gross features, thus the basic histopathological examination supported by additional diagnostic methods allow to establish the definitive diagnosis in most cases of cutaneous tumor or tumor-like lesions. And it is important that physicians and pathologists are aware of this unusual tumour-like nonneoplastic lesion.
