Abstract：
BACKGROUND: Malignant tumors with rhabdoid features are rare, highly aggressive, and some of them are characterized by SMARCB1 (INI1) loss. Although cases of rhabdoid carcinoma are extremely rare, its occurrence in the colon has been reported previously.
METHODS: A 71-year-old Japanese female patient presented with loss of appetite, fatigue, and weight loss. Computed tomography demonstrated a tumor in the right colon that infiltrated the surrounding kidneys and swelling of the left supraclavicular and periaortic lymph nodes. Laparotomy revealed that the tumor was unresectable because it had directly invaded the head of the pancreas and duodenum. Therefore, ileocecal vascularized bulky lymph nodes were sampled, and gastrojejunostomy with Braun\'s anastomosis and ileotransversostomy were performed as palliative procedures. Histopathological examination of the lymph nodes revealed that the neoplastic cells had rich eosinophilic cytoplasm and eccentrically located large nuclei characteristic of rhabdoid carcinoma. In addition, these neoplastic cells lacked SMARCB1 expression; therefore, the patient was diagnosed with SMARCB1-negative rhabdoid carcinoma. The postoperative course was uneventful. Molecular analysis confirmed that the neoplastic cells had high microsatellite instability (MSI); therefore, two cycles of pembrolizumab were administered. However, no clinical benefit was noted, and the patient died 3 months postoperatively.
CONCLUSIONS: This is the first report of a case of SMARCB1-negative rhabdoid colon carcinoma with high MSI treated with pembrolizumab. Rhabdoid carcinoma is highly aggressive; therefore, additional studies are required to determine the therapeutic strategy for SMARCB1-negative rhabdoid colorectal carcinoma.
METHODS: A 71-year-old Japanese female patient presented with loss of appetite, fatigue, and weight loss. Computed tomography demonstrated a tumor in the right colon that infiltrated the surrounding kidneys and swelling of the left supraclavicular and periaortic lymph nodes. Laparotomy revealed that the tumor was unresectable because it had directly invaded the head of the pancreas and duodenum. Therefore, ileocecal vascularized bulky lymph nodes were sampled, and gastrojejunostomy with Braun\'s anastomosis and ileotransversostomy were performed as palliative procedures. Histopathological examination of the lymph nodes revealed that the neoplastic cells had rich eosinophilic cytoplasm and eccentrically located large nuclei characteristic of rhabdoid carcinoma. In addition, these neoplastic cells lacked SMARCB1 expression; therefore, the patient was diagnosed with SMARCB1-negative rhabdoid carcinoma. The postoperative course was uneventful. Molecular analysis confirmed that the neoplastic cells had high microsatellite instability (MSI); therefore, two cycles of pembrolizumab were administered. However, no clinical benefit was noted, and the patient died 3 months postoperatively.
CONCLUSIONS: This is the first report of a case of SMARCB1-negative rhabdoid colon carcinoma with high MSI treated with pembrolizumab. Rhabdoid carcinoma is highly aggressive; therefore, additional studies are required to determine the therapeutic strategy for SMARCB1-negative rhabdoid colorectal carcinoma.
摘要：
背景：具有横纹肌样特征的恶性肿瘤很少见，极具侵略性,其中一些具有SMARCB1(INI1)损失的特征。尽管横纹肌样癌的病例极为罕见，先前已报道其在结肠中的发生。
方法：一名71岁的日本女性患者出现食欲不振，疲劳,和减肥。计算机断层扫描显示右结肠肿瘤浸润周围肾脏，左锁骨上和主动脉周围淋巴结肿胀。剖腹手术显示肿瘤无法切除，因为它直接侵入了胰腺和十二指肠的头部。因此,回盲区血管化大淋巴结取样，胃空肠吻合术伴Braun吻合术和回肠吻合术作为姑息性手术。淋巴结的组织病理学检查显示，肿瘤细胞具有丰富的嗜酸性细胞质和偏心定位的大细胞核，这是横纹肌样癌的特征。此外,这些肿瘤细胞缺乏SMARCB1表达；因此，患者被诊断为SMARCB1阴性横纹肌样癌.术后病程顺利。分子分析证实肿瘤细胞具有高度的微卫星不稳定性(MSI);因此,我们给药了两个周期的派博利珠单抗.然而,没有发现临床益处，患者术后3个月死亡。
结论：这是首次报道一例SMARCB1阴性横纹肌样癌伴高MSI的派姆单抗治疗。横纹肌样癌是高度侵袭性的；因此，需要更多的研究来确定SMARCB1阴性横纹肌样结直肠癌的治疗策略.
方法：一名71岁的日本女性患者出现食欲不振，疲劳,和减肥。计算机断层扫描显示右结肠肿瘤浸润周围肾脏，左锁骨上和主动脉周围淋巴结肿胀。剖腹手术显示肿瘤无法切除，因为它直接侵入了胰腺和十二指肠的头部。因此,回盲区血管化大淋巴结取样，胃空肠吻合术伴Braun吻合术和回肠吻合术作为姑息性手术。淋巴结的组织病理学检查显示，肿瘤细胞具有丰富的嗜酸性细胞质和偏心定位的大细胞核，这是横纹肌样癌的特征。此外,这些肿瘤细胞缺乏SMARCB1表达；因此，患者被诊断为SMARCB1阴性横纹肌样癌.术后病程顺利。分子分析证实肿瘤细胞具有高度的微卫星不稳定性(MSI);因此,我们给药了两个周期的派博利珠单抗.然而,没有发现临床益处，患者术后3个月死亡。
结论：这是首次报道一例SMARCB1阴性横纹肌样癌伴高MSI的派姆单抗治疗。横纹肌样癌是高度侵袭性的；因此，需要更多的研究来确定SMARCB1阴性横纹肌样结直肠癌的治疗策略.
