Transverse sinus-tentorium splitting approach for pineal region tumors--case report.

A 15-year-old boy with a large pineal region mass was admitted to our institute. The tentative diagnosis was mixed germ cell tumor. Tumor resection was carried out via a transverse sinus-tentorium splitting approach. The tumor tissue was completely resected, and no operative complication other than transient vertical gaze paresis was noted. The histological diagnosis was mixed germ cell tumor composed of mature and immature teratoma, germinoma, and embryonal carcinoma. After three courses of chemotherapy, the patient underwent external irradiation. He remained asymptomatic with no signs of recurrence 42 months after the surgery. The combination of the infratentorial supracerebellar approach and the occipital transtentorial approach provides excellent views and work space above and below the tentorial notch. Transverse sinus section is not mandatory for this approach, but sectioning of the unilateral transverse sinus and the tentorium along the rectal sinus allows retraction of the falx and the underlying brain to the opposite side. Thus, a much wider horizontal and vertical projection is obtained. This approach enables safer and more extensive tumor removal for large pineal region tumors.