Feather Folliculoma in Eight Broiler Chickens

Abstract

Eight broiler chickens with feather folliculoma, 46 to 50 days of age, were subjected to pathological investigation. The lesions were single or multiple and observed as discrete, hard and ellipsoidal pale yellowish nodules or protuberant masses measuring 2 to 16 cm in the greatest dimension in the various cutaneous areas including the dorsal waist and the lateral thigh. On the cut surface, the lesions consisted of many spaces filled with a caseous pale yellowish material. Histologically, the lesions were multilocular structures confined to the dermis. The structures consisted of variably sized and shaped cysts lined by stratified squamous epithelia with hyperkeratosis and hyperplastic basal and prickle cells, and they were filled with feather remnants including barbs and barbules as well as laminated keratin. Based on the findings which indicated characteristic multilocular cysts with differentiation from basal cells to feather epithelia, the present cases were diagnosed as feather folliculoma. This is the first report of feather folliculoma in broiler chickens.