Division of Gastrointestinal Surgery, Department of General Surgery, Fengdu People's Hospital, Chongqing, China.
Department of Cardiothoracic Surgery, Children's Hospital of Chongqing Medical University; Ministry of Education Key Laboratory of Child Development and Disorders; National Clinical Research Center for Child Health and Disorders; China International Science and Technology Cooperation base of Child development and Critical Disorders; Chongqing Key laboratory of Pediatrics, No.136 Zhongshan Second Road, Chongqing, 400014, China.
World J Surg Oncol. 2022 Aug 10;20(1):256. doi: 10.1186/s12957-022-02721-z.
Gastrointestinal melanoma is usually metastatic in origin, and primary melanoma within the gastrointestinal tract is rarely reported. Colon is considered to be an extremely uncommon site for primary melanomas. Herein, we report the first case of a large primary melanoma within the transverse colon with gastric involvement. CT scan found a mass within the colon, which seemed to connect to the gastric antrum. Esophagogastroscopy showed an ulcerated lesion in the greater curvature of the stomach. Subsequent colonoscopy identified a large ulcerated lesion rendering significant stenosis of the transverse colon. Biopsy following colonoscopy indicated a diagnosis of colonic melanoma based on pathological findings, which identified submucosal malignant melanoma cells with epithelioid and spindle features. Immunohistochemical stains were positive for S-100, HMB-45, Vimentin, and Melan-A. A series of clinical and imaging examinations revealed no suspicious primary cutaneous or ocular lesions. The diagnosis of primary colonic melanoma was considered. A radical transverse colectomy with subtotal gastrectomy were conducted subsequently. Definite diagnosis of primary colonic melanoma can be established after ruling out the possibility of being a metastasis from other more common primary sites. Primary colonic melanomas are a challenge to diagnose and often need a multidisciplinary treatment approach, including surgery, BRAF-targeted therapy, and immunotherapy.
胃肠道黑色素瘤通常为转移性起源，而胃肠道原发性黑色素瘤则很少见。结肠被认为是原发性黑色素瘤极不常见的部位。在此，我们报告首例胃累及的横结肠大型原发性黑色素瘤病例。CT 扫描发现结肠内有一肿块，似乎与胃窦相连。食管胃十二指肠镜检查显示胃大弯处有一溃疡性病变。随后的结肠镜检查发现一大型溃疡性病变导致横结肠显著狭窄。结肠镜检查后的活检根据病理结果提示结肠黑色素瘤的诊断，其中发现具有上皮样和梭形特征的黏膜下恶性黑色素瘤细胞。免疫组化染色 S-100、HMB-45、波形蛋白和 Melan-A 均为阳性。一系列临床和影像学检查未发现可疑的原发性皮肤或眼部病变。考虑诊断为原发性结肠黑色素瘤。随后进行了根治性横结肠切除术和胃大部切除术。排除其他更常见的原发性部位转移的可能性后，可明确诊断为原发性结肠黑色素瘤。原发性结肠黑色素瘤的诊断具有挑战性，通常需要多学科治疗方法，包括手术、BRAF 靶向治疗和免疫治疗。
