Recurrent Pineocytoma

Pineal tumors are very rare, accounting for 0.4- 1.0 % of intracranial tumours in adults. About 40% of these are germinomas, being the most common tumor type in this anatomical localization (1). Furthermore, possible pineal region masses are pineal parenchymal cell tumors, glioma, meningioma, metastases, and non-neoplastic masses (pineal cysts, lipoma, epidermoid etc.) are among the other mass lesions encountered in the pineal region. Tumors that arise from pineal parenchymal cell account for less than 15% of all pineal region neoplasms. There are two types of pineal cell neoplasms: pineocytoma and pineoblastoma.

Pineocytomas which are are benign, slow growing pineal parenchymal tumors of young adults are composed of mature cells that are histologically almost indistinguishable from normal pineal parenchyma (2). Pineocytomas represent approximately 45% of pineal parenchymal tumors. Typically, they are less than 3 cm in diameter and rarely asociated with hydrocephalus (3). Unlike other pineal neoplasms there is no male predomiance. The average age at diagnosis is 34 years (4). Pineocytoma also mimics pineal cyst or pineloblastoma (3).

Pineoblastomas, on the other hand are highly malignant neoplasms that are composed of undifferentiated or immature pineal cells (2). Mostly, their diameter is usually larger than 3 cm and nearly 100% are asociated with obstructive hydrocephalus (3).

On MRI, pineal neoplasms usually appear as round or lobulated, solid tumors which tend to be hypo- or isointense on T1-weighted images and show diffuse and heterogenous contrast enhancement (2,5). Nevertheless, a histopathologic evaluation is required for a specific diagnosis of pineal cell tumors, which is not possible with MRI studies alone.

To the best of our knowledge , no case regarding the recurrence of pineocytoma has been reported in the literature.