Jokinen Chris H, Argenyi Zsolt B
Department of Pathology, Division of Dermatology, University of Washington, Seattle, WA 98195, USA.
J Cutan Pathol. 2010 Jan;37(1):35-42. doi: 10.1111/j.1600-0560.2009.01293.x. Epub 2009 Mar 25.
Neurofibroma (NF) is a relatively common cutaneous tumor, which typically presents little diagnostic difficulty. Occasionally, however, pleomorphic cells may be present in NF raising consideration of other neoplasms like malignant peripheral nerve sheath tumor (MPNST).
This study examines the clinicopathologic and immunohistochemical features of 11 dermal and subcutaneous 'atypical' NF.
9/11 (82%) atypical NF were from females, aged 8-70 years. One patient had neurofibromatosis-1. Most presented on the extremities or trunk. The atypical cells had large hyperchromatic, irregular nuclei, and were arranged in a distinct lamellar or fibrillar pattern. Some tumors were hypercellular, but marked density characteristic of MPNST was not observed. All were nonplexiform. Mitoses were mostly absent. The pleomorphic cells expressed S-100 protein. All were negative for p53. MIB-1 was negative in 7/10 (70%) and stained only rare cells in 3 (30%). Epithelial membrane antigen (EMA) and p16 expression were variable. Of six patients with available follow-up, no tumor recurred and none developed malignancy (range 6-63, mean 33 months).
Superficial atypical NF, while morphologically unusual, has no apparent association with neurofibromatosis-1 or short-term risk of recurrence or malignant transformation. Awareness of this variant is important in order to avoid misdiagnosis of a more aggressive neoplasm.
神经纤维瘤（NF）是一种相对常见的皮肤肿瘤，通常诊断难度不大。然而，偶尔神经纤维瘤中可能出现多形性细胞，这就需要考虑其他肿瘤，如恶性外周神经鞘瘤（MPNST）。
本研究检查了11例皮肤和皮下“非典型”神经纤维瘤的临床病理和免疫组化特征。
11例非典型神经纤维瘤中9例（82%）为女性，年龄8至70岁。1例患者患有神经纤维瘤病1型。大多数肿瘤位于四肢或躯干。非典型细胞具有大的深染、不规则核，呈独特的层状或纤维状排列。一些肿瘤细胞丰富，但未观察到MPNST特有的明显密度特征。所有肿瘤均为非丛状型。大多无核分裂象。多形性细胞表达S-100蛋白。所有肿瘤p53均为阴性。MIB-1在10例中有7例（70%）为阴性，3例（30%）仅少数细胞染色阳性。上皮膜抗原（EMA）和p16表达各异。6例有随访资料的患者中，无肿瘤复发，也无恶变发生（随访时间6至63个月，平均33个月）。
浅表性非典型神经纤维瘤虽然形态不寻常，但与神经纤维瘤病1型无明显关联，也无短期复发或恶变风险。认识到这种变异型对于避免误诊为侵袭性更强的肿瘤很重要。
