Dedifferentiated endometrial adenocarcinoma with neuroendocrine differentiation and ballooning-cell features: Report of a rare entity with an unusual histology

• Main Authors: Sara Makhdoum, MD, M. Ruhul Quddus, MD, M. Phil (Path), Michele M. Lomme, MD, Katrine Hansen, MD, W. Dwayne Lawrence, MD, MSc (Path)
• Format: Article
• Language: English
• Published: Elsevier 2019-03-01
• Series: Human Pathology: Case Reports
• Online Access: http://www.sciencedirect.com/science/article/pii/S2214330018301330
• ISSN: 2214-3300

A 63-year-old Caucasian woman underwent total hysterectomy with bilateral salpingo-oophorectomy due to abnormal uterine bleeding. Gross examination of the hysterectomy specimen revealed a large polypoid mass filling the endometrial cavity. Histological examination revealed a tumor with two unique morphologic patterns with no overlap or transition from one pattern to the other. The low-grade component consisted of FIGO grade 1 endometrioid adenocarcinoma with unusual “balloon-cell” change, while the high grade component was an undifferentiated carcinoma with neuroendocrine features. Both components exhibited MLH1 and MSH6 loss by immunohistochemistry. To our knowledge, the current case is only the 5th documented case of dedifferentiated endometrioid carcinoma with neuroendocrine features. Keywords: Endometrium, Dedifferentiated carcinoma, Neuroendocrine features, Balloon-cell change, Microsatellite instability