Primary Amelanotic Rhabdoid Melanoma: A Case Report with Review of the Literature.
Primary Amelanotic Rhabdoid Melanoma: A Case Report with Review of the Literature.
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DOI：
10.1159/000441347
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发表时间：
2015-09
影响因子：
0.9
通讯作者：
Sawamura D
中科院分区：
文献类型：
--
作者：
Kaneko T;Korekawa A;Akasaka E;Rokunohe D;Nakano H;Sawamura D
原发性横纹肌样黑色素瘤（PRM）是黑色素瘤的一种罕见变体。在此，我们描述了一个原发性无色素横纹肌样黑色素瘤的病例，并回顾了以前报道的PRM病例的临床病理特征。一位63岁的日本男性，在左足跟部发现一个大小为21 × 18 mm的无色素红色颗粒状肿瘤，周围无色素斑。光镜检查发现肿瘤块完全由多边形肿瘤细胞组成，类似肺泡。肿瘤细胞也是松散的奇异的核，突出的核仁和大的透明的胞质内含物。不存在黑色素。肿瘤细胞S-100、MART-1、HMB-45和vimentin呈弥漫性强阳性表达，结蛋白、αSMA和突触素呈阴性表达。根据以前的综述，PRM倾向于无色素和结节。S-100蛋白和波形蛋白在所有病例中染色，与HMB-45的低染色相反，HMB-45在我们的病例中为阳性。PRM的预后仍然存在争议，因为这种肿瘤的发生非常罕见，并且已报告的确诊病例数量很少。认识到这种罕见的实体是重要的，在临床实践中，即使是熟练的皮肤科医生，以避免误诊为其他肿瘤，并确定后续的治疗原则。
Primary rhabdoid melanoma (PRM) is a rare variant of melanoma. Herein, we describe a case of primary amelanotic rhabdoid melanoma and review the clinicopathological features of previously reported cases of PRMs. A 63-year-old Japanese man presented with a nonpigmented red granular tumor without peripheral pigmented macules on the left heel measuring 21 × 18 mm in size. Light microscopic examination revealed a tumor mass composed entirely of polygonal neoplastic cells resembling pulmonary alveoli. Tumor cells were also discohesive with bizarre nuclei, prominent nucleoli and large hyaline cytoplasmic inclusions. No melanin pigment was present. Tumor cells were strongly and diffusely positive for S-100, MART-1, HMB-45 and vimentin, while negative for desmin, αSMA and synaptophysin. According to previous reviews, PRM tends to be amelanotic and nodular. S-100 protein and vimentin stained in all cases contrary to low stainability for HMB-45, which was, by contrast, positive in our case. Prognosis of PRM remains controversial due to the very rare occurrence of this tumor and the small number of confirmed cases that have been reported. Recognition of this rare entity is important in clinical practice even for skillful dermatologists to avoid misdiagnosis with the other tumors and to determinate the subsequent treatment principles.