Chaplin Anna, Conrad David M, Tatlidil Cuneyt, Jollimore Jason, Walsh Noreen, Covert Alan, Pasternak Sylvia
From the *Division of Anatomical Pathology, Dalhousie University, Halifax, Nova Scotia, Canada; †Department of Pathology, Valley Regional Hospital, Kentville, Nova Scotia, Canada; and ‡Department of Patholgy, Colchester Regional Hospital, Truro, Nova Scotia, Canada.
Am J Dermatopathol. 2010 May;32(3):310-312. doi: 10.1097/DAD.0b013e3181b9e5c4.
A 48-year-old woman attended a physician because of a solitary cutaneous nodule on the left lower leg. Microscopic examination of the excisional specimen revealed a dermal tumor composed of nests of epithelioid cells exhibiting clear cytoplasm. They had centrally located vesicular nuclei with distinct nucleoli. A rich network of capillaries was present throughout. The tumor showed an infiltrative border. There was no epidermal involvement. Periodic acid-Shif (PAS) and PAS-Diastase stains demonstrated glycogen deposition within the cytoplasm of the clear cells. Immunohistochemical evaluation revealed that the tumor cells were positive for HMB-45 and microftalmia associated transcription factor (MITF). Focal desmin positivity was also seen. The tumor cells were negative for S-100 protein, alfa smooth muscle actin, HHF-35, and various cytokeratins. The case is one of a primary cutaneous pecoma. Pecomas are rare, recently described mesenchymal tumors composed of perivascular epithelioid cells. They constitute a spectrum of lesions in different organs including angiomyolipoma of the kidney and liver, sugar tumor of the lung, lymphangiomatosis, and lymphangiomyoma. Primary cutaneous PEComas are exceptionally rare and have only recently been recognized. To date, these are approximately 22 cases in the English literature. Follow-up data is limited but they appear to behave in a benign fashion. We report an additional case with the goal of alerting dermatopathologists to this distinctive unusual neoplasm.
一名48岁女性因左小腿出现单个皮肤结节就诊于医生。对切除标本进行显微镜检查发现，真皮肿瘤由巢状上皮样细胞组成，这些细胞胞质透明。它们有位于中央的泡状核，核仁明显。整个肿瘤内有丰富的毛细血管网。肿瘤边界呈浸润性。无表皮受累。过碘酸希夫（PAS）和PAS-淀粉酶染色显示透明细胞胞质内有糖原沉积。免疫组化评估显示肿瘤细胞HMB-45和小眼畸形相关转录因子（MITF）呈阳性。也可见局灶性结蛋白阳性。肿瘤细胞S-100蛋白、α平滑肌肌动蛋白、HHF-35和各种细胞角蛋白均为阴性。该病例为原发性皮肤PEComa。PEComa是罕见的、最近才被描述的由血管周上皮样细胞组成的间叶性肿瘤。它们在不同器官构成一系列病变，包括肾和肝的血管平滑肌脂肪瘤、肺的糖瘤、淋巴管瘤病和淋巴管肌瘤。原发性皮肤PEComa极为罕见，直到最近才被认识到。迄今为止，英文文献中约有22例。随访数据有限，但它们似乎表现为良性。我们报告另外一例，目的是提醒皮肤病理学家注意这种独特的不寻常肿瘤。
