MRI findings of rare intracranial germ cell tumors of the pineal region with pathologic

Objective: To analyze the MRI features of rare intracranial germ cell tumors of the pineal region compared with pathologic findings. Methods: The MRI and pathologic data of 32 patients with rare intracranial germ cell tumors of the pineal region were reviewed retrospectively. All cases were proved by surgery and pathological examinations. Results: Fourteen teratomas with malignant transformations were cyst-solidary which were mixed signals on plain MRI and the solid components showed obvious enhancement. The adiposity signals could be seen in teratomas. The level of serum or CSF AFP was high. Microscopically, many tissue components could be seen. The signal of 6 yolk sac tumors were homogeneous, and they had great enhancement after enhanced scanning. Increasing of preoperative serum AFP level could be seen in all patients. The 5 embryonal carcinomas were well-defined margin masses and heterogeneous with cystoid variation and necrosis and moderate to severe edema. The solid components showed obvious enhance. The signals of 7 mixed germ cell tumors were atypical, which depended on the components of germ cell tumors. Conclusion: The MRI findings of the rare intracranial germ cell tumors of the pineal region(teratomas with malignant transformations, yolk sac tumors endodermal sinus tumor, embryonal carcinomas and mixed germ cell tumors) show some feature which are correlated with pathology. Suggestive diagnosis could be made combined with clinical data and MRI features. (authors)