Clinicopathological analysis of perivascular epithelioid cell tumor of the head and neck / 临床与实验病理学杂志

Purpose To investigate the clinicopathological features, treatment and prognosis of perivascular epithelioid cell tumor ( PEComa) of the head and neck. Methods Two cases of PEComa were analyzed by studying clinical data, histopathologic and immu-nohistochemical ( EnVision) changes and the related literatures were reviewed. Results Case 1 was a 26-year-old woman with a re-current larynx tumor, and case 2 was diagnosed in a 56-year-old man with a left nasal cavity mass. Their tumors were well-demarcated, and ranged from 2. 5 to 3. 5 cm in diameter. Microscopically, the tumors were composed of epithelioid cells arranged in nets, organoid pattern. The tumor cells had abundant pale eosinophilic granular to clear cytoplasm, vesicular nuclei, and mild atypia. The stroma was rich in capillaries, sinusoidal vasculature. There was mitotic activity and focal necrosis. By immunohistochemistry, the tumor cells were diffusely or focally positive for vimentin (2/2), HMB-45(1/2), Melan-A(2/2), SMA(2/2), Calponin(2/2), desmin(1/2), and TFE3(1/2). They were negative for CK, CD10, S-100, CgA, Syn, and MyoD1. Conclusion PEComa of the head and neck is rare. Definite diagnosis depends upon the comprehensive analysis of histopathology and coexpression of melanocytic and myoid mark-ers. The differential diagnosis include paraganglioma, malignant melanoma and metastatic carcinoma. Few PEComas of the head and neck behaved in an aggressive fashion with distant or loco-regional metastases and died of disease-related causes, it should be regarded as tumors with a malignant potential.

Update on perivascular epithelioid cell tumors of the urinary system / 国际外科学杂志

The perivascular epithelioid cell (PEC) is a cell type constantly present in a group of tumors called PEComas(perivascular epithelioid cell tumors). PEC expresses myogenic and melanocytic markers,such as HMB45. PEComa is a widely accepted entity now. PEComas are related to the genetic alterations of tuberous sclerosis complex (TSC), an autosomal dominant genetic disease due to losses of TSC1 or TSC2 genes. PEComas are rare in the urinary system and there are some open questions about PEComas regarding its histogenesis, the definition of epithelioid angiomyolipoma and the identification of the histological criteria of malignancy. This review provides an update on PEComas of the urinary system.