Microscopic features of the fibropapilloma from a subadult male red deer (Cervus elaphus) sampled after a hunt in Portugal showing pseudocarcinomatous hyperplasia with orthokeratotic hyperkeratosis and hypergranulosis. (A) Extensive proliferation of fibroblasts in the dermis. (B) Presence of koilocytes in the spinal stratum and intranuclear basophilic inclusions.