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.

Objective To survey prevalence of behavior problems in children of off-farm workers and effects of family factors on children' s behavior problems.Methods The study was done in the whole 7 schools for off-farm workers' children in Shanghai Baoshan district,including all 3 ～ 6 grades students of primary school and 1 ～3 grades students of junior high school.Totally 4350 students finished survey (95.4％).Achenbach' s child behavior checklist ( CBCL,parent' s version) and general family questionnaire were used.Results ( 1 ) Prevalence of behavior problems in children was 11.2％ ; 12.8％ 12 ～ 16 years children had behavior problems( 14.7％boys and 10.4％ girls) ; 11.4％ of one-child children had behavior problems compared with that of 11.2％ child with siblings children ( x2 =0.038,P ＞ 0.05 ).(2) Total score ( 20.64 ± 17.67 ) and factor scores of thought problems,depressed,hyperactivity,delinquent rule-breaking behavior were higher than those of Chinese norm (P ＜0.05 or P ＜ 0.01 ) among 6 ～ 11 years boy group.Total score ( 17.23 ± 14.73 ) and scores of thought problems,depressed,social problems,hyperactivity,delinquent rule-breaking behavior were higher than those of Chinese norm (P ＜ 0.01 ) among 6 ～ 11 years girl group.Among 12 ～ 16 years boy group,total score (20.44 ± 19.32) and all factor scores of CBCL were higher than those of Chinese norm(P＜0.01 ).Total score ( 17.02 ± 16.72) and scores of immature,delinquent rule-breaking behavior,brutality were higher than those of Chinese norm(P ＜ 0.05 or P ＜0.01 ) among 6 ～ 11 years girl group.(3)Multi-regression analysis showed that poor parent-child relationship was the most important predict factor for higher score of CBCL among all family risk factors (P ＜ 0.05 ).Conclusion Children of the off-farm workers and their families need special mental health care program.