Section of General Surgery, Department of Surgery, Medical College, Aga Khan University, Stadium Road, Karachi 74800, Pakistan.
World J Surg Oncol. 2011 Feb 1;9:14. doi: 10.1186/1477-7819-9-14.
Melanomas within the alimentary tract are usually metastatic in origin. On the other hand, primary melanomas of the gastrointestinal tract are relatively uncommon. There are several published reports of melanomas occurring in the esophagus, stomach, small bowel, and anorectum. The occurrence of primary melanoma of the colon has, however, only been rarely reported. The optimum modus operandi for the management of primary colonic melanoma remains nebulous due to the limited number of reports in literature.
A comprehensive search of Medline, Cochrane and Highwire was performed using the following keywords: 'melanoma', 'malignant melanoma', 'primary melanoma', 'colon', 'gastrointestinal tract', 'alimentary tract', 'digestive tract', and 'large bowel'. All patients with primary melanoma localized to the colon were included in the review. Patients with metastatic melanomas to the gastrointestinal (GI) tract and primary melanomas localized to the GI tract in anatomic locations other than colon were excluded.
There have been only 12 reported cases of primary melanoma of the colon to date. The average age of patients on presentation was 60.4 years without any significant gender predilection. Right colon (33%) and cecum (33%) were the most common sites for the occurrence of primary colonic melanoma while abdominal pain (58%) and weight loss (50%) were the most common presenting complaints. Colonoscopy is the most reliable diagnostic investigation and offers the additional advantage of obtaining tissue for diagnosis. S-100 and HMB-45 are highly sensitive and specific for the diagnosis of this malignancy. For primary colonic melanomas that have not metastasized to any distant parts of the body, surgical resection with wide margins appears to be the treatment of choice. Although the management was individualized in every case, most of the authors preferred traditional hemicolectomy as the favored surgical approach. Chemotherapeutic agents including interferons, cytokines, biological agents and radiation therapy for brain metastases have been reported as adjuvant and palliative options while considering malignant melanomas in general. The average recurrence-free interval was 2.59 years. Nine of the 12 reports documented follow-up in their patients. Two of these 9 (22.2%) patients died.
Primary melanoma of the colon is a rare clinical entity. Whenever a seemingly primary melanoma is detected in an atypical location such as the colon, it is prudent to conduct a thorough clinical investigation to consider the possibility of metastatic disease. Further studies are needed to document the long term follow-up, survival advantage and safety of the management approaches employed in patients with primary colonic melanoma. Based on current data, surgical resection appears to be appropriate management for primary colonic melanomas; unless the disease has metastasized to distant sites where surgery may have a limited palliative role.
消化道内的黑色素瘤通常是转移性的。另一方面，胃肠道的原发性黑色素瘤则相对少见。有几篇文献报道了发生在食管、胃、小肠和肛门直肠的黑色素瘤。然而，结肠原发性黑色素瘤的发生仅被少数文献报道过。由于文献报道数量有限，结肠原发性黑色素瘤的最佳手术方式仍不明确。
通过以下关键词在 Medline、Cochrane 和 Highwire 上进行了全面搜索：“黑色素瘤”、“恶性黑色素瘤”、“原发性黑色素瘤”、“结肠”、“胃肠道”、“消化道”和“大肠”。将所有局限于结肠的原发性黑色素瘤患者纳入本综述。排除转移性胃肠道黑色素瘤和非结肠部位的胃肠道原发性黑色素瘤患者。
迄今为止，仅有 12 例结肠原发性黑色素瘤的报道。患者就诊时的平均年龄为 60.4 岁，无明显性别倾向。右半结肠（33%）和盲肠（33%）是原发性结肠黑色素瘤最常见的发生部位，而腹痛（58%）和体重减轻（50%）是最常见的首发症状。结肠镜检查是最可靠的诊断性检查，并且具有获取组织进行诊断的额外优势。S-100 和 HMB-45 对该恶性肿瘤的诊断具有高度敏感性和特异性。对于尚未转移到身体其他远处部位的原发性结肠黑色素瘤，广泛切除似乎是首选的治疗方法。虽然每个病例的治疗方法都因人而异，但大多数作者更喜欢传统的右半结肠切除术作为首选的手术方法。干扰素、细胞因子、生物制剂和脑转移放疗等化疗药物已被报道为辅助和姑息治疗选择，适用于一般的恶性黑色素瘤。无复发生存期的平均值为 2.59 年。在 12 份报告中有 9 份记录了患者的随访情况。其中 2 例（22.2%）患者死亡。
结肠原发性黑色素瘤是一种罕见的临床实体。无论何时在结肠等非典型部位发现看似原发性黑色素瘤，都应进行彻底的临床检查，以考虑转移疾病的可能性。需要进一步研究来记录原发性结肠黑色素瘤患者长期随访、生存获益和治疗方法的安全性。根据目前的数据，手术切除似乎是治疗原发性结肠黑色素瘤的合适方法；除非疾病已经转移到远处，在这种情况下，手术可能只能起到有限的姑息作用。
