Department of Pathology, Massachusetts General Hospital, Boston, MA, USA.
Am J Surg Pathol. 2011 Oct;35(10):1570-7. doi: 10.1097/PAS.0b013e31822389b7.
Neurocristic hamartomas are rare pigmented lesions comprised of melanocytes, Schwann cells, and pigmented dendritic spindle cells that involve the skin and soft tissue. Malignant transformation can rarely arise within neurocristic hamartomas. Up to date, there has been only 1 series of 7 cases of malignant neurocristic hamartomas (MNHs), with 3 cases that developed metastases. We present the histology and clinical course of 3 additional cases of MNH, 2 of which were metastatic. CD117 was strongly positive in all cases with available archival materials--the tumors and background neurocristic hamartoma of 3 cases, and 1 lymph node metastasis; however, KIT sequencing for exons 11, 13, 17, and 18 was negative. Mutational analyses of recurrent mutations of 17 cancer genes, including BRAF and KIT, were also negative. Although our series is small, KIT overexpression in MNH does not seem to correlate with gene mutation. The lack of BRAF, NRAS, GNAQ, and KIT mutations seems to support the notion that MNH may be distinct from conventional melanoma and from other dermal melanomas, such as malignant blue nevi and melanoma arising in congenital nevi.
神经嵴错构瘤是一种罕见的含黑素细胞、雪旺细胞和色素性梭形树枝状细胞的色素性病变,可累及皮肤和软组织。神经嵴错构瘤很少发生恶性转化。迄今为止,仅有 1 组 7 例恶性神经嵴错构瘤(MNH)的报道,其中 3 例发生转移。我们报告了另外 3 例 MNH 的组织学和临床过程,其中 2 例发生了转移。在有存档材料的 3 例肿瘤和背景神经嵴错构瘤,以及 1 例淋巴结转移中,所有病例的 CD117 均强阳性;然而,对 11、13、17 和 18 外显子的 KIT 测序均为阴性。包括 BRAF 和 KIT 在内的 17 个癌症基因的复发突变的分析也为阴性。尽管我们的系列较小,但 MNH 中 KIT 的过表达似乎与基因突变无关。缺乏 BRAF、NRAS、GNAQ 和 KIT 突变似乎支持这样一种观点,即 MNH 可能与传统黑色素瘤以及其他真皮黑色素瘤(如恶性蓝痣和先天性痣中发生的黑色素瘤)不同。