Understanding and Managing Pineal Parenchymal Tumors of Intermediate Differentiation: An In-Depth Exploration from Pathology to Adjuvant Therapies

Background: Pineal parenchymal cell tumors constitute a rare group of primary central nervous system neoplasms (less than 1%). Their classification, especially the intermediate subtype (PPTIDs), remains challenging. Methods: A literature review was conducted, navigating through anatomo-pathological, radiotherapy, and neurosurgical dimensions, aiming for a holistic understanding of these tumors. Results: PPTIDs, occupying an intermediate spectrum of malignancy, reveal diverse histological patterns, mitotic activity, and distinct methylation profiles. Surgical treatment is the gold standard, but when limited to partial removal, radiotherapy becomes crucial. While surgical approaches are standardized, due to the low prevalence of the pathology and absence of randomized prospective studies, there are no shared guidelines about radiation treatment modalities. Conclusion: Surgical removal remains pivotal, demanding a personalized approach based on the tumor extension. This review underscores the considerable variability in treatment approaches and reported survival rates within the existing literature, emphasizing the need for ongoing research to better define optimal therapeutic strategies and prognostic factors for PPTIDs, aiming for further and more detailed stratification among them.