Clinicopathologic characteristics of undifferentiated/dedifferentiated endometrial carcinoma

WANG Yun; JIN Wei; SONG Xin; TIAN Xia; LIU Ai-jun

doi:10.3969/j.issn.1007-8096.2017.04.005

Abstract：Objective To study the clinical and pathological characteristics of undifferentiated/dedifferentiated endometrial carcinoma and to analyze the points of diagnosis and differential diagnosis.Methods The cases were collected in Department of Pathology of PLA General Hospital from January 2005 to December 2015.The clinical data,morphologic features,immunohistochemistry and special staining results,and the related literature were reviewed.Results 8 cases were conformed to the diagnosis,including 6 cases of dedifferentiated carcinoma and 2 cases of undifferentiated carcinoma.The median age was 55 years and there were 6 cases happened postmenopausally.Irregular vaginal bleeding was the most common symptom.FIGO stage was IC (3/8),ⅡB(2/8),Ⅲ (2/8) and Ⅳ (1/8).Small round cells with necrosis and deep invading of the uterine could be seen in all of these cases,and giant tumor cell was only found in one case.Rhabdoid cells were noticed in some cases (4/8) and mitoses were numerous (average ＞ 20/HPF).Vascular involvement could also be seen in most cases(6/8).In 6 cases,we could see associated low-grade endometrioid carcinoma components (＜ 10％),and so the diagnosis of dedifferentiated carcinomas were established.Immunohistochemical staining showed that undifferentiated carcinomas were locally positive for Vimentin,CD99,CD56,Syn and at least positive for one kind of epithelial markers (e.g.,pan-CK,EMA,CK7,CK8/18).Most of them were positive for CD138 and all of them were negative for ER,PR.4 cases appeared as loss of mismatch repair protein expression and microsatellite instability.The Gomori collagen staining showed the tumor cells were nested.The patients of FIGO Ⅲ-Ⅳwere died in 10-18 months (average 13.3 months),and the others were well recovered.Conclusions Undifferentiated/dedifferentiated endometrial carcinoma is a rare kind of tumor.A series of biomarkers should be used in the diagnosis and at least one kind of epithelial markers should be expressed.Gomori collagen staining can help us in differential diagnosis.Its molecular mechanism needs to be further studied.