Collision tumor of ovary:imaging features and pathology / 中华放射学杂志

ABSTRACT

Objective To explore imaging findings and pathological features of ovarian collision tumors. Methods A retrospective analysis of preoperative imaging findings was performed in 8 female patients with surgical-pathological proven ovarian collision tumors. CT scans were performed in 5 cases, both CT and MRI were performed in 2 cases, and non-enhanced MR scans were performed in 1 pregnancy woman. Imaging results were compared with pathologic findings. Results Ovarian collision tumors in the eight patients consisted of 2 types tumors, originated from different ovarian tissues including surface epithelial cells, germ cell, or sex cord-stromal cell. Of the 8 ovarian collision tumors, 5 were located in the left ovary, and 3 in the right ovary. Ovarian collision tumors consisted of surface epithelial tumor and germ cell tumor (n=6) including mucinous cystadenoma and teratoma (n=4), mixed cystadenoma and teratoma (n=1), and serous cystadenoma and struma-ovarii (n=1). Ovarian collision tumors in two cases consisted of surface epithelial tumor and sex cord-stromal tumor, and were mucinous cystadenoma and fibroma, respectively. Imaging findings includedall tumors in the 8 cases presented big or huge multiple complicated cystic mass with 9 to 26 cm in diameter. Germ cell tumor or sex cord-stromal tumor in collision tumor was smaller and located inside the tumor (n=3) and on the tumor wall (n=5). The boundary between two types of tumors in ovarian collision tumor was distinct and clear. Typical imaging features and densities (signals) of different tumors in ovarian collision tumors can be found on CT or MRI. Conclusions Ovarian collision tumors has some specific imaging and pathological characteristics. Imaging examination is helpful for most accurate diagnosis of ovarian collision tumors.