An aggressive, unresected pineoblastoma in an adult woman: the role of exclusive radiotherapy - a case report and literature review.

Abstract

Introduction: The pineal gland is a small, endocrine structure located in the posterior cranial fossa, playing a critical role in regulating sleep-wake cycles. Pineal parenchymal tumours (PPTs) are rare, accounting for less than 1% of central nervous system malignancies. These tumours include pineocytomas (benign), intermediate-grade tumours (PPTs) and aggressive pineoblastomas (PBL), which represent the most dangerous subtype. PBL are fast-growing, high-grade tumours often classified as grade IV. This paper presents a rare case of unresected PBL in a young woman, leading to bilateral blindness and the role of exclusive radiotherapy (RT) as a treatment modality.

Objective: This case report aims to explore the effectiveness of exclusive RT in treating an unresected PBL in a young patient, emphasising the tumour's aggressiveness and the therapeutic challenges it presents.

Case presentation: A 35-year-old woman with no significant medical history presented with progressively worsening headaches and visual acuity loss. Imaging revealed a pineal region tumour, confirmed as PBL through stereotactic biopsy. The patient had bilateral papilledema and developed hydrocephalus due to tumour growth, leading to pressure on surrounding structures. Due to the patient's refusal of chemotherapy (CT), RT was chosen as the sole treatment option.RT was delivered in two phases: a craniospinal dose of 36 Gy and a boost of 18 Gy to the tumour. The patient tolerated the treatment well, with only mild nausea and fatigue. Follow-up imaging at 3 months showed a 38% reduction in tumour size and improvement in hydrocephalus, although the patient remained bilaterally blind. At 24 months post-treatment, the tumour remained stable, suggesting a positive long-term outcome with exclusive RT.

Discussion: PBL are aggressive tumours with a high potential for leptomeningeal dissemination. Surgery, when feasible, is considered the primary treatment for pediatric cases, but in adults, data are sparse. In this case, the patient's refusal of CT made RT the only viable option. Recent studies suggest that RT alone can improve survival, particularly when combined with craniospinal irradiation and tumour boosts. However, the role of surgery and CT in adult PBL remains debated, with mixed results in the literature regarding their impact on overall survival.While some studies indicate no significant survival benefit from extensive tumour resection, others suggest that total resection can improve prognosis. The case highlights that exclusive RT can be a life-saving treatment for patients who cannot undergo surgery or CT, despite the tumour's aggressive nature. Further research is needed to establish standardised protocols for managing adult PBL.

Conclusion: This case demonstrates the potential of exclusive RT as an effective treatment for PBL in patients who cannot undergo surgery. Despite the patient's permanent blindness, RT led to a significant reduction in tumour size and stabilisation of the disease. More research is necessary to define the most effective treatment strategies for PBL, particularly in adults, where surgical options may be limited.