Shintaku Masayuki, Wada Kyosuke, Wakasa Tomoko, Ueda Maho
Department of Pathology, Osaka Red Cross Hospital, Osaka, Japan.
Acta Cytol. 2011;55(5):467-72. doi: 10.1159/000330676. Epub 2011 Oct 8.
Malignant peripheral nerve sheath tumor (MPNST) is a heterogeneous group of neoplasms that shows divergent differentiation potential, and the cytological findings are largely nonspecific. There are no previous reports specifically alluding to the cytological findings of MPNST showing fibroblastic differentiation (fibroblastic MPNST).
A 59-year-old woman with neurofibromatosis type 1 developed a rapidly enlarging tumor on the scalp. A metastatic lesion in the ileum was examined cytologically. Irregularly shaped clusters of spindle cells with wavy or buckled nuclei and fibrillary cytoplasm were found as well as many similar isolated cells. Histopathologically, the tumor showed a spindle cell sarcomatous appearance typical of MPNST. Immunohistochemically, the tumor cells were negative for S-100 protein and epithelial membrane antigen but immunoreactive for vimentin, CD10 and CD34. Ultrastructurally, the tumor cells were not invested by the basal lamina and had abundant rough-surfaced endoplasmic reticulum and a subplasmalemmal accumulation of microfilaments with dense patches. These immunohistochemical and ultrastructural findings were consistent with fibroblastic or myofibroblastic differentiation.
Although there are no cytological findings specific for fibroblastic MPNST, the wide spectrum of differentiation in MPNST should be kept in mind during cytological examination of soft tissue sarcomas.
恶性外周神经鞘瘤（MPNST）是一组异质性肿瘤，具有不同的分化潜能，其细胞学表现大多无特异性。此前尚无专门提及显示成纤维细胞分化的MPNST（成纤维细胞性MPNST）细胞学表现的报道。
一名1型神经纤维瘤病的59岁女性头皮上出现一个迅速增大的肿瘤。对回肠的一个转移病灶进行了细胞学检查。发现了形状不规则的梭形细胞簇，细胞核呈波浪状或弯曲状，细胞质呈纤维状，还有许多类似的孤立细胞。组织病理学上，肿瘤表现为MPNST典型的梭形细胞肉瘤外观。免疫组化显示，肿瘤细胞S-100蛋白和上皮膜抗原阴性，但波形蛋白、CD10和CD34呈免疫反应阳性。超微结构上，肿瘤细胞未被基膜包绕，有丰富的粗面内质网，微丝在质膜下聚集并有致密斑。这些免疫组化和超微结构表现符合成纤维细胞或肌成纤维细胞分化。
虽然成纤维细胞性MPNST没有特异性的细胞学表现，但在软组织肉瘤的细胞学检查中应牢记MPNST广泛的分化谱。
