Papillary tumor of pineal region: Case reports

Abstract

Background: The papillary tumor of the pineal region (PTPR) was a new distinct entity described in 2003 WHO classification and later included in the subsequent 2007 and 2016 WHO classification of Central Nervous System tumours. They are commonly associated with obstructive hydrocephalus and are difficult to distinguish from other clinical entities, more particularly pineocytoma. Due to the limited number of reported cases, treatment strategies are not well established. Case report: We report two cases of PTPR who presented with headache impaired gaze and diplopia. In first case MRI showed a cystic mass in the third ventricle and pineal region whereas the tumor had displaced the tectal plate in second case. The initial squash suggested a neoplastic lesion of probable glial origin favoring ependymoma. On microscopy, the tumor displayed papillary architecture with perivascular pseudo rosettes displaying multi layering of cuboidal to columnar cell with vesicular nucleus. Based on histological features the differential diagnostic conditions considered were choroid plexus tumor, papillary ependymoma, choroid plexus carcinoma, PTPR, and metastatic carcinoma. PTPR was confirmed on immunohistochemistry workup. Both the patients had recurrence, after one year and six months respectively. Conclusion: PTPR is an important differential diagnosis to be considered in cases where the tumoris arising in the vicinity of pineal region showing papillary architecture. Keywords: pineal region papillary tumor; PTPR; pineal region; subcommissural organ