Mast Cell-Rich Pleomorphic Pineocytoma: A Rare Entity

Pineal region tumors constitute a rare group of neoplasms. Primaryneuronaltumor that intrinsicallyarisefromthepineal gland are referred to as pineal parenchymal tumors (PPTs). Their neuropathological spectrum is divided into well-differentiated “ pineocytoma ” (World Health Organization [WHO] grade I), pineal parenchymal tumors of intermediate differentiation and papillary tumor of pineal region (WHO grades II and III), and poorly differentiated “ pinealoblastoma ” (WHO grade IV). 1 Pleomorphic cytological variant of pineocytoma has been rarely reported in the medical literature mainly in form of case reports. A 45-year-old man with a recent history of right-sided stroke presented to the neurosurgery department with complaint of headache for last 1 month. Multislice computed tomography (CT) imaging revealed an ill-de ﬁ ned hyperdense space-occupying lesion with internal calci ﬁ cation. The tumor was located in the region of pineal gland with extension into the adjacent lateral ventricle and resultant mild obstructive hydrocephalus. MRI scan revealed a hyperdense nodular lesion measuring 24 (cid:1) 18mm with scant peritumoral edema ( ► Fig. 1A and 1B ). Following placement of a ventriculo peritoneal shunt, stereotactic biopsy was performed and submitted to the pathology department. Histopathological examination revealed a pineal parenchymal neoplasm with varied morphology. In some areas, the tumor cells were small and uniform resembling pinealocytes, and