Department of Pathology, Bon Secours-Richmond Health System, Richmond, VA, USA.
Ann Diagn Pathol. 2010 Apr;14(2):69-73. doi: 10.1016/j.anndiagpath.2009.07.003. Epub 2010 Feb 4.
The mucosal surfaces represent the third most common site of origin for melanoma, after the skin and ocular uveal tract. However, anorectal mucosal melanoma is a rare neoplasm, usually occurring in the sixth and seventh decades of life. It may often be confused clinically with other pathologic entities, such as prolapsed rectal polyps and hemorrhoids. The prognosis of anorectal melanoma is poor; this is at least in part attributable to the relatively large size that such tumors have frequently achieved at presentation, as well as their rich vascular network. In particular, anorectal melanoma in children and adolescents is extraordinarily uncommon. The authors herein report 2 examples of that tumor in 11-year-old and 19-year-old patients; one was alive and tumor-free after 6 years, whereas the other died with osseous and hepatic metastasis at the same time point. The authors emphasize the need for differential diagnostic inclusion of melanocytic malignancies when considering anorectal masses in pediatric individuals. Systematic collation and evaluation of pediatric melanomas of the anus and rectum are needed, to better define the biologic attributes of those neoplasms.
黏膜表面是黑色素瘤的第三个常见起源部位，仅次于皮肤和眼部葡萄膜。然而，肛门直肠黏膜黑色素瘤是一种罕见的肿瘤，通常发生在六七十岁。临床上，它常与其他病理实体混淆，如直肠脱垂息肉和痔疮。肛门直肠黑色素瘤的预后较差；这至少部分归因于这些肿瘤在出现时通常已经达到较大的尺寸，以及它们丰富的血管网络。特别是，儿童和青少年的肛门直肠黑色素瘤非常罕见。作者在此报告了 2 例 11 岁和 19 岁患者的此类肿瘤；其中 1 例在 6 年后仍存活且无肿瘤，而另 1 例在同一时间点死于骨转移和肝转移。作者强调，在考虑儿科个体的肛门直肠肿块时，需要将黑色素瘤纳入鉴别诊断。需要对肛门和直肠的儿科黑色素瘤进行系统的整理和评估，以更好地确定这些肿瘤的生物学特征。
