Clinical Features of Pineal Parenchymal Tumors of Intermediate Differentiation (PPTID): A Single-Institution Series

Abstract

Pineal parenchymal tumors of intermediate differentiation (PPTID) are rare tumors of the pineal gland. Their treatment is often heterogeneous due to the lack of literature to compile standardized treatments. Although no single institution has large numbers of cases, our experience has been that the clinical course is more varied and complicated than reported. We reviewed the clinical data for all patients with pathology found to be consistent with PPTID at our institution between the years 2006 and2019. Nine patients were identified. At initial diagnosis, all were treated with surgery and 4 of 9 patients underwent gross total resection. Adjuvant radiation therapy to the resection bed was administered in 6 of 9 patients. Mean follow-up time was 95.3 months. Mean progression-free survival was 50.5 months, with a tendency to be longer for male sex and after gross total resection. Seven patients developed a recurrence. Five of 6 known locations of first recurrences had either distant metastases or dissemination of disease. First recurrences were treated with radiation alone in 5 patients, craniospinal radiation with multiagent chemotherapy in 1 patient, and surgery with radiation therapy in 1. At last follow-up, 2 patients had died. Herein, we report clinical patterns of disease progression and treatment patterns of PPTID. Many patients progressed during the follow-up period. Disseminated disease was the most common presentation at recurrence. Ultimately, given the risk of recurrence and dissemination at recurrence, more aggressive treatment strategies should be considered. Specifically, our series suggests a benefit of adjuvant radiation at initial diagnosis for grade II patients.