[Ovarian epidermoid cyst and endometrioid carcinoma: do they share their origin?]

A case of a well differentiated endometrioid adenocarcinoma of the ovary in combination with an epidermoid cyst is described. A typical epidermoid cyst without skin appendages could be observed. In direct neighborhood, there was a typical endometrioid carcinoma with some foci of squamous metaplasia. There was no continuum between the squamous metaplasia of the carcinoma and the wall of the epidermoid cyst. In addition, the benign cyst and the carcinoma shared some of their immunohistochemical profile. This case highlights the still unsolved question about the origin of epidermoid cysts and adds to the hypothesis that they arise from pluripotent coelomic epithelium.