Zelger B W, Zelger B G, Rappersberger K
Department of Dermatology, University of Innsbruck, Austria.
Am J Dermatopathol. 1997 Apr;19(2):138-46. doi: 10.1097/00000372-199704000-00007.
Myofibroblastic differentiation occurs in 10-20% of all dermatofibromas, affecting < 25% of cells. We report on a series of 36 dermatofibromas collected from > 1,500 fibrohistiocytic lesions (2%), with more prominent (> 25%) myofibroblastic differentiation characterized by markedly slender and elongated spindle cells positive for smooth muscle markers. While most of the lesions did not otherwise differ from ordinary dermatofibromas, three cases (0.2%) from the neck-shoulder region of male adults showed extensive myofibroblastic features (> 90%). Clinically, these three lesions measured approximately 1 cm and had a firm consistency, with the differential diagnosis of some fibrohistiocytic tissue response. Histologically, densely packed cells and prominent, partially nodular, stromal sclerosis with focal palisading of nuclei indicate some overlap with other rare variants of fibrohistiocytic tissue response, such as cellular benign and palisading cutaneous fibrous histiocytoma. Yet, these features together with focal whorled nesting of more epithelioid cells (one case) also caused considerable diagnostic problems to exclude other myofibroblastic as well as (malignant) spindle cell lesions such as (palisaded) myofibroblastoma, dermatofibrosarcoma protuberans, and neurothekeoma. Immunohistochemically, all lesions were markedly (> 90%) labeled for smooth muscle markers (HHF35, anti-SMA) and with NK1C3 (CD57), while a broad panel for other spindle cell tumors, such as pan-keratin, S100 protein, EMA, desmin, CD34, CD31, and KiM1p, were negative. Electron microscopy of two cases revealed prominent endoplasmic reticulum and Golgi complex, numerous intermediate filaments, attachment plaques, and focal basal lamina formation. No recurrence was seen during a follow-up of 9 (two cases) and two years, respectively.
肌成纤维细胞分化见于所有皮肤纤维瘤的10% - 20%，累及不到25%的细胞。我们报告了从1500多个纤维组织细胞性病变中收集的36例皮肤纤维瘤（占2%），其中肌成纤维细胞分化更显著（>25%），其特征为平滑肌标志物阳性的明显细长梭形细胞。虽然大多数病变与普通皮肤纤维瘤无其他差异，但3例（0.2%）来自成年男性颈肩部区域的病变表现出广泛的肌成纤维细胞特征（>90%）。临床上，这3个病变大小约为1 cm，质地硬，鉴别诊断考虑为某些纤维组织细胞性组织反应。组织学上，细胞密集堆积以及显著的、部分呈结节状的间质硬化伴核的局灶性栅栏状排列提示与纤维组织细胞性组织反应的其他罕见变异型有一定重叠，如细胞性良性和栅栏状皮肤纤维组织细胞瘤。然而，这些特征连同更上皮样细胞的局灶性漩涡状巢状排列（1例）也给排除其他肌成纤维细胞性以及（恶性）梭形细胞病变，如（栅栏状）肌成纤维细胞瘤、隆突性皮肤纤维肉瘤和神经鞘瘤带来了相当大的诊断难题。免疫组化方面，所有病变均有明显（>90%）的平滑肌标志物（HHF35、抗平滑肌肌动蛋白）和NK1C3（CD57）标记，而针对其他梭形细胞肿瘤的广泛抗体谱，如泛角蛋白、S100蛋白、上皮膜抗原、结蛋白、CD34、CD31和KiM1p均为阴性。2例病例的电子显微镜检查显示内质网和高尔基体复合体突出、大量中间丝、附着斑以及局灶性基底膜形成。分别对9例（2例）病例进行了随访，随访期分别为9年和2年，均未见复发。
