Simultaneous occurrence of a granulosa cell tumour and a serous papillary cystadenocarcinoma in the same ovary. A case report

Collision Tumors in Ovary: Case Series and Literature Review

Histologically distinct tumors that coexist in an organ without any histological admixture at their interface are denominated collision tumors. We report 3 cases of colliding mature cystic teratoma with mucinous cystadenoma and a case of mature cystic teratoma colliding with benign Brenner tumor in the ovary. We also provide a literature review based on 35 previously published ovarian collision cases. Ovarian tumors from all classes, benign, borderline and malignant lesions may collide. Both our case series and the literature review indicate that ovarian tumor collisions tend to be clinically and ultrasonographically/radiologically unrecognized. The awareness among surgeons, radiologists and pathologists of this rare phenomenon and histological recognition are crucial in order to offer adequate treatment to patients. There is a need to identify novel and more specific imaging clues pointing towards collision tumors in the ovary.

CT and MR imaging of ovarian tumors with emphasis on differential diagnosis

Ovarian tumors are classified on the basis of tumor origin as epithelial tumors (serous and mucinous tumors, endometrioid and clear cell carcinomas, Brenner tumor), germ cell tumors (mature and immature teratomas, dysgerminoma, endodermal sinus tumor, embryonal carcinoma), sex cord-stromal tumors (fibrothecoma; granulosa cell, sclerosing stromal, and Sertoli-Leydig cell tumors), and metastatic tumors. Epithelial tumors are primarily cystic and, when malignant, are associated with varying proportions of a solid component. Papillary projections are a distinctive feature of epithelial tumors. Profuse papillary projections are highly suggestive of borderline (low-malignant-potential) or malignant tumor. Ovarian teratomas demonstrate lipid material at computed tomography and magnetic resonance (MR) imaging. Malignant germ cell tumors manifest as a large, complex abdominal mass that contains both solid and cystic components. Tumor markers are helpful in diagnosis. The radiologic appearance of sex cord-stromal tumors varies from small solid masses to large multicystic masses. Granulosa cell tumors are usually large multicystic masses with solid components. Fibrothecoma, sclerosing stromal tumor, and Sertoli-Leydig cell tumors are usually solid masses. Fibromas have very low signal intensity on T2-weighted MR images. Certain radiologic findings predominate for each type of tumor. Knowledge of these key features of ovarian tumors provides the criteria for making a specific diagnosis or substantially narrowing the differential diagnosis.