TWO CASES OF PERIANAL RHABDOMYOSARCOMA

A 17-year-old woman presented to our hospital with a complaint of pain around the anus and was admitted on suspicion of perianal cystoma. The cystoma was found to be a parenchymal tumor, and examination of a biopsy specimen revealed cystic rhabdomyosarcoma that appeared to have arisen in the anal sphincter. Abdominoperineal resection of the rectum was performed and followed by adjuvant chemotherapy (VAC therapy) and radiation therapy. The patient remains free of relapse as of 6 years 9 months after treatment. The other patient was a 21-year-old woman who presented with swelling of the left inguinal lymph nodes and perianal pain. Colostomy was performed to relieve anal obstruction caused by a perianal tumor. Biopsy revealed cystic rhabdomyosarcoma. The patient had bone metastasis and lymph node metastasis and died 3 months after the operation. Twenty-five cases of perianal rhabdomyosarcoma have been reported in Japan. A review of the literature suggests that although recent advances in chemotherapy have contributed to improving the survival rate, it appeares necessary to completely resect the tumor, and follow it by appropriate adjuvant chemotherapy.