Tachibana Mitsuhiro, Nozawa Masashi, Kamimura Kazuyasu, Tsutsumi Yutaka
Department of Diagnostic Pathology, Shimada General Medical Center, Shimada, JPN.
Department of Surgery, Shimada General Medical Center, Shimada, JPN.
Cureus. 2022 Jun 24;14(6):e26270. doi: 10.7759/cureus.26270. eCollection 2022 Jun.
Sarcomatoid carcinoma (SCA) of the small bowel is a rare aggressive variant of small intestinal cancer accompanying a poor prognosis. The tumor primarily affects middle-aged and elderly patients. We report herein a 67-year-old Japanese male who manifested anemia. He had a history of asbestos exposure 30 years earlier. An abdominal computed tomography (CT) scan showed a 6.5-cm aneurysmal, dilated mass of the small intestine. Capsule endoscopy revealed a large circumferential hemorrhagic ulcerative lesion in the jejunum. Biopsy indicated sarcomatoid carcinoma, and partial resection of the small bowel and adjacent transverse colon and omentum was performed. In addition to the T3N0M0 jejunal giant sarcomatoid carcinoma (SCA), a 3-mm small localized peritoneal (omental) malignant mesothelioma (LMM) was also incidentally included. Synchronous presentation of small intestinal and mesothelial malignancies is extremely rare, and the avoidance of incorrect clinical staging is critically important. Surgical resection is still considered the best first-line therapy, because of a poor response to chemotherapy and radiotherapy. Dual-color fluorescent in situ hybridization (FISH) for p16/CDKN2A and chromosome 9 indicated homologous deletion of p16/CDKN2A in SCA and a normal pattern in LMM. Methylthioadenosine phosphorylase (MTAP) was negative in SCA but positive in LMM. Both tumors consistently expressed BRCA1-associated protein 1 (BAP1). Tumor necrosis factor receptor-associated factor 7 (TRAF7) was suppressed, and neural cell adhesion molecule L1 precursor (NCAML1/L1CAM) was agitated in both tumors. Diffuse and strong expression of programmed death-ligand 1 (PD-L1) and the association of tumor-infiltrating lymphocytes in SCA may indicate a potential for PD-L1-targeted immunotherapy for treating this type of aggressive cancer. PD-L1 was focally expressed in LMM. The postoperative course was uneventful for two years.
小肠肉瘤样癌（SCA）是一种罕见的侵袭性小肠癌变体，预后较差。该肿瘤主要影响中老年患者。我们在此报告一名67岁表现为贫血的日本男性。他30年前有石棉接触史。腹部计算机断层扫描（CT）显示小肠有一个6.5厘米的动脉瘤样扩张肿块。胶囊内镜检查发现空肠有一个大的环形出血性溃疡性病变。活检显示为肉瘤样癌，遂进行了小肠及相邻横结肠和网膜的部分切除术。除了T3N0M0空肠巨大肉瘤样癌（SCA）外，还意外发现了一个3毫米的小局限性腹膜（网膜）恶性间皮瘤（LMM）。小肠和间皮恶性肿瘤的同步出现极为罕见，避免错误的临床分期至关重要。由于对化疗和放疗反应不佳，手术切除仍被认为是最佳的一线治疗方法。对p16/CDKN2A和9号染色体进行双色荧光原位杂交（FISH）显示，SCA中p16/CDKN2A存在同源缺失，而LMM为正常模式。甲硫腺苷磷酸化酶（MTAP）在SCA中为阴性，但在LMM中为阳性。两种肿瘤均持续表达BRCA1相关蛋白1（BAP1）。肿瘤坏死因子受体相关因子7（TRAF7）受到抑制，神经细胞黏附分子L1前体（NCAML1/L1CAM）在两种肿瘤中均有上调。SCA中程序性死亡配体1（PD-L1）的弥漫性强表达以及肿瘤浸润淋巴细胞的存在可能表明针对这种侵袭性癌症进行PD-L1靶向免疫治疗具有潜力。PD-L1在LMM中呈局灶性表达。术后两年病情平稳。
