Takayama Tetsuyoshi, Nakame Ayako, Suzuki Masaomi, Asano Hiroshi, Jin Ling
Department of General Surgery, Saitama Medical University, Saitama, Japan.
Department of Pathology, Saitama Medical University, Saitama, Japan.
J Anus Rectum Colon. 2024 Jan 25;8(1):39-42. doi: 10.23922/jarc.2022-043. eCollection 2024.
Inflammatory myofibroblastic tumors (IMTs) are neoplastic lesions characterized by the proliferation of spindle cells with myofibroblastic features and lymphocyte infiltration. Primary lesions can develop in several locations but rarely arise in the colon as described herein. The present case was that of a 69-year-old woman who visited our hospital with complaints of bloody bowel discharge and a prolapsed mass from the anus. A 20-mm tumor was identified on visual and digital examination. Lower gastrointestinal endoscopy revealed a pedunculated, elevated lesion above the dentate line, which showed contrast enhancement on abdominal computed tomography. The patient was preoperatively diagnosed with an anal polyp, which was resected transanally. During the procedure, a mobile tumor coated by anal epithelium was observed at the 11 o'clock position above the dentate line. Deeper parts of the tumor were contiguous with the internal anal sphincter (IAS) muscle. Suspecting a neoplastic lesion, we resected the mass with part of the IAS. Tumor histopathology after surgery led to a final diagnosis of an IMT of the anus. IMT is difficult to diagnose preoperatively. No adjuvant therapy has been formally established; thus, an adequate surgical margin and close monitoring are essential.
炎性肌纤维母细胞瘤（IMTs）是一种肿瘤性病变，其特征为具有肌纤维母细胞特征的梭形细胞增殖和淋巴细胞浸润。原发性病变可发生于多个部位，但如本文所述，很少发生于结肠。本病例为一名69岁女性，因便血和肛门肿物脱出前来我院就诊。通过视诊和指诊发现一个20毫米的肿瘤。下消化道内镜检查显示在齿状线以上有一个带蒂的隆起病变，腹部计算机断层扫描显示有对比增强。患者术前被诊断为肛门息肉，并经肛门切除。手术过程中，在齿状线以上11点位置观察到一个被肛门上皮覆盖的可移动肿瘤。肿瘤的深部与肛门内括约肌（IAS）肌肉相邻。由于怀疑是肿瘤性病变，我们切除了肿物及部分IAS。术后肿瘤组织病理学检查最终诊断为肛门IMT。IMT术前难以诊断。尚未正式确立辅助治疗方法；因此，足够的手术切缘和密切监测至关重要。
