One case showed pseudoepitheliomatons hyperplasia and neutrophil infiltration, microabscess formation and plasma cell infiltration in the dermis.Small blood vessels surrounded by plasma cells.

• 1例肛周黏膜鳞状上皮呈假上皮瘤性增生，上皮内有中性粒细胞漫润、微小服肿形成，真皮层大量浆细胞浸润伴小血管周围围管性浸润；