Invasive ovarian endometrioid adenofibroma with omental implants and collision with endometrial adenocarcinoma

A case of endometrioid adenofibroma of the ovary with omental implants, extensive invasion into the wall of the ipsilateral fallopian tube, and collision with an endometrial papillary adenocarcinoma is reported. Fewer than 35 malignant cystadenofibromas and adenofibromas have been reported. In all of these cases, the malignant epithelium was believed to originate from preexisting benign tumors. This case is unusual in that it demonstrated no malignant epithelium beyond that of a borderline tumor, but met the criteria of malignancy because of its invasiveness and metastasis.