Pineal parenchymal tumors with intermediate differentiation: a long-term follow up study in Helsinki Neurosurgery.

BACKGROUND: Pineal parenchymal tumors of intermediate differentiation (PPTIDs) are rare lesions with particular features compared to other pineal parenchymal tumors.

METHODS: We present a retrospective review of the patients with histologically confirmed PPTIDs that were operated on in our department between 1997 and 2015. A demographic analysis, and an evaluation of preoperative status, surgical treatment, as well as immediate and long-term clinical and radiological outcomes were conducted.

RESULTS: Fifteen patients with PPTIDs were operated on between 1997 and 2015. Gross total removal was achieved in 11 cases; two patients underwent near-total resection, one partial resection, and one received brachytherapy after an endoscopic biopsy. Other nine patients required external radiation therapy (4 due to a pleomorphic histology of their lesion including pineoblastoma features in 3 of them; 3 after a subtotal resection; two for tumor recurrence). No patient received chemotherapy. The survival rate of our patients was 57.1% at a mean follow-up of 137.2 ± 77.6 (39-248) months.

CONCLUSIONS: A proper multidisciplinary management of PPTIDs based on a gross total removal of the lesion, and an adjuvant radiotherapy in selected cases, may improve the overall survival of these aggressive tumors.