Radical resection of nongerminomatous pineal region tumors via the occipital transtentorial approach based on arachnoidal consideration: experience on a series of 143 patients.

Background: The role of radical resection for nongerminomatous pineal region tumors is still controversial. The purpose of this study was to present the surgical results in a large series and evaluate the feasibility of radical surgical strategy.

Methods: We retrospectively reviewed the records of 143 patients with nongerminomatous pineal region tumors surgically treated via an occipital transtentorial approach between 2000 and 2011. The tumor was small (<2 cm) in 14.7 % of patients, medium (2-4 cm) in 52.4 %, and large (>4 cm) in 32.9 %.

Results: Gross total tumor removal was achieved in 91.6 % of patients, subtotal in 7.0 %, and partial in 1.4 %. Histological diagnosis was nongerminomatous germ cell tumor in 41.3 %, pineal parenchymal tumor in 14.7 %, glial tumors in 28.7 %, and miscellaneous in 15.4 %. The overall complication and mortality rate was 18.2 % and 0.7 %, respectively. Permanent morbidity occurred in 5.6 % of patients, including hemianopsia in 3.5 % and Parinaud syndrome in 2.1 %. Hydrocephalus was resolved in 82.1 % without surgery for the CSF diversion. Sixty-eight patients with malignant tumors underwent radiotherapy; 35 also received adjuvant chemotherapy. One hundred thirty patients were successfully followed up with a mean duration of 43 months. Finally, 86.9 % of the patients achieved a favorable functional outcome (mRS ≤ 2), 3.1 % had an mRS score of 3, 1.5 % had an mRS score of 4, and 8.5 % had died (mRS = 6).

Conclusions: Radical surgery was recommended as the optimal treatment for nongerminomatous pineal region tumors. Favorable results could be achieved by experienced neurosurgeons. Hydrocephalus could be cured by radical tumor removal in the majority of cases. The occipital transtentorial approach was indicated for most pineal region tumors, but surgeon's preference and experience should also be considered. New understanding of the arachnoid membranes of this region may be helpful for tumor resection.