Multiple generalized follicular cysts in a stallion

This case report describes a case of multiple follicular cysts in a 4-year-old Spanish purebred stallion. The lesions ranged in size from 0.5 to 3 cm in diameter, and were firm, well circumscribed and nonpruritic. They developed over a 2-year period with a generalized distribution affecting all body regions. Five nodules were removed and histopathologically corresponded to simple epidermal cysts (infundibular and isthmus-catagen) with squamous epithelium and a keratin filled cavity. Lesions were not evident at birth but their number, early age of detection, slow growth and lack of previous trauma suggested that they were congenital. To the authors' knowledge, this condition has not previously been reported either in young horses or in Spanish purebred horses.