Abstract
Objective:Dedifferentiated endometrioid adenocarcinoma is a recently defined uterine tumor composed of low-grade endometrioid adenocarcinoma and undifferentiated carcinoma. Herein, we present clinicopathologic, morphologic, and immunohistochemical features of 5 cases of dedifferentiated endometrioid adenocarcinoma.Material and Methods:All cases which were diagnosed as mixed endometrial adenocarcinoma (endometrioid+undifferentiated carcinoma) or dedifferentiated endometrioid adenocarcinoma between January 2008 and December 2014 were retrieved from the archives of our institution’s pathology department.Results:The median age of the patients was 58 years. Polypoid growth pattern was seen in 3 patients and 2 were diagnosed at advanced stage. All patients received either external radiotherapy, brachytherapy, chemotherapy or an appropriate combination according to the stage. Only one patient died of the disease. Microscopically, there was a sharp demarcation between the two tumor components. The undifferentiated carcinoma component was composed of diffuse sheets of monomorphic cells lacking any differentiation. Focal pleomorphism and rhabdoid features were also noted. The undifferentiated carcinoma component was variably positive for PAX-8, cytokeratin, EMA, estrogen receptor, and neuroendocrine markers.Conclusion:Misdiagnosis of undifferentiated carcinoma in dedifferentiated endometrioid adenocarcinoma as grade 3 endometrioid adenocarcinoma is not uncommon. The recognition of morphologic and immunohistochemical features of this newly described entity is crucial because it alters treatment and prognosis.
Highlights
Uterine and ovarian dedifferentiated endometrioid adenocarcinoma (DEAC) was first described by Silva et al in 2006 [1]
133 Dedifferentiated endometrioid adenocarcinoma (CK) AE1-AE3, epithelial membrane antigen (EMA), vimentin, chromogranin A, synaptophysin, CD56, estrogen receptor (ER) [used to distinguish endocervical (ER-) from endometrial (ER+) adenocarcinoma], and progesterone receptor (PR) for routine diagnostic purposes were performed in all cases
Three patients were diagnosed with grade 1 or 2 endometrioid endometrial adenocarcinoma, others with undifferentiated carcinoma (UC) and non-keratinizing squamous cell carcinoma
Summary
Uterine and ovarian dedifferentiated endometrioid adenocarcinoma (DEAC) was first described by Silva et al in 2006 [1]. Based on the definition of the authors, low-grade endometrioid adenocarcinoma (EmC) and undifferentiated carcinoma (UC) are two fundamental elements of this tumor. The low-grade component in these tumors is usually International Federation of Gynecology and Obstetrics (FIGO) grade 1 or 2 EmC. The UC component is characterized by proliferation of medium-sized, homogenous epithelial cells with no glandular differentiation, which grow in a patternless manner and form solid sheets [2]. For accurate treatment and prognosis of this neoplasm, a correct pathologic diagnosis is essential [3]. We report five cases of DEAC of the uterus
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
