Objective To explore the relationship between tubal intraepithelial carcinoma (TIC) of the fimbria and pelvic high-grade serous carcinoma.Methods All 34 cases of pelvic high-grade serous carcinoma with clear fimbria were evaluated from January 2009 to June 2010,including ovarian carcinoma (n=26),tubal carcinoma (n=7) and peritoneal carcinoma (n=1).Among of these ovarian carcinomas,12 cases were surface deposits and the other 14 cases within ovarian parenchyma.All 42 cases of non highgrade serous carcinoma in this period including 13 endometrioid ovary carcinomas,11 clear cell ovary carcinomas,11 mucinous ovary carcinomas,6 low-grade serous ovary carcinomas,1 low-grade serous tubal carcinoma,were also collected as a reference.The presence of tubal intraepithelial carcinomas was assessed.Based on the presence of TIC,high-grade serous ovary carcinomas were divided into TIC positive (+) and TIC negative (-) groups,and the clinical and pathological features of them were also evaluated.Results Fifteen cases (44％) were identified TIC in 34 high-grade pelvic serous carcinomas,and all of them were in the fimbria only,while none of TIC was found in control cases.There were significant difference between the two groups (x2=23.086,P=0.000).Eleven cases(42％) were identified TIC in all 26 high-grade ovarian serous carcinomas,in which 8 cases with unilateral ovary carcinomas were associated with ipsilateral TIC,2 cases with bilateral ovary carcinomas associated with unilateral TIC and one case with bilateral ovary carcinoma was associated with bilateral TIC.Four TIC (4/7) were identified in 7 cases with high-grade tubal serous carcinomas,and there was no presence of TIC in the 1 high-grade serous peritoneal carcinoma.Of all 26 high-grade ovarian serous carcinomas,6/11 cases were surface deposits,and 5/11 were parenchyma tumors in TIC (+) group while 6/15 cases were surface deposits and 9/15 were parenchyma tumors in TIC (-) group,in which there were correlated in distribution of TIC between the two groups( P＞0.05 ).The average diameter of ovarian cancer were 6.9 and 6.5 cm between the two groups with no significant differences ( t=0.409,P=0.690).Conclusion TIC is specific to high-grade serous carcinomas and maybe have something to do with the pathogenesis of pelvic serous carcinomas.