Abstract
BACKGROUND: Anal fistula cancer is rare and definitive treatment has not yet been established. Laparoscopic abdominoperineal resection is generally the first choice of treatment if the cancer is determined to be resectable. However, complicated anal fistula cancer often requires extensive resection. Using a myocutaneous flap for reconstruction after resection in such cases, radical resection can be performed regardless of the size of the anal fistula cancer. CASE PRESENTATION: We report two cases in which we performed laparoscopic abdominoperineal resection with extensive buttock resection and myocutaneous flap reconstruction for widespread anal fistula cancer. One of the cases was reconstruction with a posterior thigh flap, the other was with a bilateral expanded gluteus maximus flap. Both cases were anal fistula cancers that developed from complicated anal fistulas. CONCLUSIONS: If the size of anal fistula cancer is large and extended buttock resection is necessary, radical resection of anal fistula cancer is possible using myocutaneous flap for reconstruction after extended abdominoperineal resection.