ABSTRACT
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.