Department of Dermatology, University of California Davis Health System, Sacramento, California, USA Touro University California College of Osteopathic Medicine, Vallejo, California, USA.
Dermatol Online J. 2022 Jan 15;28(1). doi: 10.5070/D328157058.
Perivascular epithelioid cell tumor (PEComa) expresses melanocytic and smooth muscle markers. A man with a primary malignant cutaneous (distal left forearm) PEComa is reported. Immunohistochemistry demonstrated MiTF, HMB-45, caldesmon, desmin, and smooth muscle actin, as well as BCL1, CD10, and CD68. Next generation sequencing showed four pathogenic genomic aberrations involving BIRC3, FANCC, TP53, and TSC1 genes. His work-up was negative for metastatic disease; a wide local excision was performed. Including the reported patient, cutaneous PEComa has been described in 65 individuals: primary benign (N=58), primary malignant (N=5), and metastatic malignant (N=2). Cutaneous PEComa typically presented as a painless, slowly growing nodule of <2 centimeters on the lower extremity of a woman in her fifth decade. The neoplasms consisted of epithelioid cells, spindle cells, or both. The most reliable markers were MiTF (100%), HMB45 (94%), and NKIC3 (94%) for melanocytes and smooth muscle actin (43%) and desmin (40%) for smooth muscle. There has been no reported recurrence of a primary cutaneous benign or malignant PEComa after complete excision. Genomic alterations in malignant PEComas frequently involve TSC1 and TSC2 genes (mTOR activators), as well as TFE3 fusions. In November 2021, the FDA approved nab-sirolimus (mTOR inhibitor) for PEComas.
血管周上皮样细胞瘤 (PEComa) 表达黑色素细胞和平滑肌标志物。报告了一名男性原发性皮肤（左前臂远端）PEComa 恶性肿瘤患者。免疫组织化学显示 MiTF、HMB-45、钙调蛋白、结蛋白和平滑肌肌动蛋白，以及 BCL1、CD10 和 CD68。下一代测序显示涉及 BIRC3、FANCC、TP53 和 TSC1 基因的四种致病性基因组异常。他的检查结果未显示转移性疾病；进行了广泛的局部切除。包括报告的患者，皮肤 PEComa 已在 65 个人中描述：原发性良性（N=58）、原发性恶性（N=5）和转移性恶性（N=2）。皮肤 PEComa 通常表现为无痛、生长缓慢的结节，位于下肢，女性在五十多岁，直径 <2 厘米。肿瘤由上皮样细胞、梭形细胞或两者组成。最可靠的标志物是 MiTF（100%）、HMB45（94%）和 NKIC3（94%）用于黑色素细胞，平滑肌肌动蛋白（43%）和结蛋白（40%）用于平滑肌。完全切除后，原发性皮肤良性或恶性 PEComa 无复发报道。恶性 PEComa 的基因组改变常涉及 TSC1 和 TSC2 基因（mTOR 激活剂）以及 TFE3 融合。2021 年 11 月，FDA 批准 nab-sirolimus（mTOR 抑制剂）用于治疗 PEComa。
