Pineal Parenchymal Tumor of Intermediate Differentiation (PPTID) and Papillary Tumor of Pineal Region (PTPR): A Review.

Background Pineal parenchymal tumors account for less than 0.3% of all CNS tumors and "Pineal parenchymal tumor of intermediate differentiation" (PPTID; World Health Organization (WHO) grades II and III) exhibit intermediary differentiation and prognosis. However "Papillary tumor of the pineal region" (PTPR; WHO grades II and III) is a distinct entity. Objectives This combination of rarity and apparent similarity often leads to perplexity regarding the treatment and prognosis among neurosurgeons. In this review, we have tried to elucidate the differences in clinical as well as treatment modalities and outcomes of these two entities. Methods We used the PubMed Database to search for all relevant articles using the keywords "pineal parenchymal tumor of intermediate differentiation" and "Papillary tumor of the pineal region." Articles having details regarding demographic and clinical variables along with treatment and outcomes were chosen for this study. Full text of these articles was analyzed, and data tabulated. Results A total of 25 articles for PPTID and 45 for PTPR were found suitable for inclusion in this study. The studies were either case reports or small retrospective series with only one systemic review for each pathology. Despite the poor quality of data, some trends were apparent. Surgical resection offered a survival benefit in both pathologies. Radiotherapy was effective in increasing the survival in PPTID, while there was little to no effect in PPTR. Chemotherapy was not found to be beneficial in either. Conclusion Both of these tumors have moderate growth rate and potential for malignant behavior. This continuum of characteristics makes their optimal treatment strategy difficult and confusing. The discussion on comprehensive literature review should give information for neurosurgeons to decide on optimal treatment strategies.