First case of hemorrhoidal carcinoma in a fistulotomy scar: successful per-anal endoscopic myectomy despite severe fibrosis - Shao, Xiaona; Toyoshima, Naoya; Haga, Toshihiro; Kusuhara, Mitsunori; Kanemitsu, Yukihide; Shen, Jianwei; Saito, Yutaka (Endoscopy, 2025)