Abstract
A 49-year-old man was first seen at the hospital in July, 1995, with a 2-year history of pus discharge and bleeding from the perianus. This was considered to be a horseshoe type perianal abscess and was treated by surgical drainage. Two months later, he underwent debridement and tight seton under the diagnosis of complex fistula ani. The patient remained symptom-free for 2 years thereafter. He was again seen at the hospital in October, 1997, with a 2-month history of bleeding from the wound. Examination revealed an ulcerative left side perianal lesion and a left inguinal lymph node swelling. Proctoscopic examination revealed no mucosal lesion in the anal canal and rectum. Biopsy of the perianal mass showed an adenocarcinoma. Miles operation with left inguinal lymph nodes dissection was performed. The carcinoma was histologically diagnosed as mucinous adenocarcinoma with inguinal lymph node metastasis. First manifestations of carcinoma of the anal canal resemble those of benign hemorrhoidal diseases, and hence histological diagnosis is required for all cases not to make misdiagnosis. In this case, if we had performed histological examinations and carcinoma had been present, we had to make the correct diagnosis at the first visit. This case that has emphasized the importance of histological diagnosis and should be noted in daily clinical scenes is presented here.
