Pineal parenchymal tumors: Case series

Abstract

Background: Pineal parenchymal tumors (PPTs) are uncommon tumors comprising of pineocytoma (PC), pineal parenchymal tumor of intermediate differentiation (PPTID) and pineoblastoma (PB). Morphological sub typing and histological grading based on mitotic index and neurofilament (NF) immunostaining are the factors affecting the survival of these patients. Treatment strategy and prognosis of PPTIDs remain controversial with limited data available on pathologic features and biologic behavior of PPTID. Case series: We report a series of 8 pineal parenchymal tumors over a period of 5 years with special reference to PPTIDs. The series includes 3 cases of PC, 2 of PPTID and 3 of PB. Patients underwent decompression, microsurgical/ stereotactic/ endoscopic biopsy. Histological features with MIB1 LI (labelling index) and NF immunostaining were studied and showed varied presentation. One case each of PC and PPTID showed ganglion like cells. Both PPTIDs showed 8% and 20% MIB1 LI. All PBs showed brisk mitosis hemorrhage and necrosis except for one case where mitosis was not clearly evident but showed high MIB1 LI (50%). Conclusion: PCs with ganglionic differentiation have an essentially benign course. Ganglionic differentiation in PPTIDs, its impact on the prognosis and as a differentiating factor between PPTID grade II and grade III needs further study.

Keywords

• Pineocytoma
• pineal parenchyma
• pineoblastoma
• MIB1 LI
• neurofilament
• synaptophysin