Журнал клинических случаев

Complete Response to Radiotherapy in a Pineal Parenchymal Tumor of Intermediate Differentiation

Abstract

Helder Picarelli, Joao Victor Savajoli, Olavo Feher and Manoel Jacobsen Teixeira

Background and Importance: Approximately 20 percent of parenchymal pineal tumors (PPT) arise from the epithelial cells and are extremely rare, especially in adults, accounting for less than 1 percent of all primary brain tumors in Europe and North America. PPT of intermediate differentiation (PPTID) was recognized as a new entity and introduced in the 2007 WHO classification, corresponding to grades II (GII) or III (GIII). Previous studies had suggested its potentially aggressive behavior and tendency for cerebrospinal fluid seeding. A standard treatment for these tumors has not yet been defined. The gross total surgical resection is indicated whenever technically feasible and the impact of adjuvant radiotherapy and chemotherapy is not established. In fact, little is known about the radiation and chemotherapy sensitivity of these tumors. Clinical Presentation: We describe a case of a recurrent PPTID (G II, Ki67:10%) which underwent to an endoscopic third ventriculostomy, biopsy and a two conformal radiation therapy course (25 fractions of 180 cGy over 4 weeks and, 3 fractions of 180 cGy, total of 5400cGy). After that, the patient was completely asymptomatic and an MRI revealed no residual mass. There was no sign of relapse by the 27-months follow-up. Conclusion: Given the paucity of good clinical evidence for a standard therapy and the fact that the currently PPTID treatment is experience-based, we conclude that radiotherapy can be considered as suitable possibility of primary treatment. Due to its rarity, prospective multi-institutional studies should be arranged to establish the optimal PPTID management.