DOI: https://doi.org/10.36347/sjmcr.2026.v14i06.056

Pages: 1563-1571

Introduction: Pineal region tumors in adults are exceptionally rare and represent a major diagnostic and therapeutic challenge, particularly when they exhibit an ambiguous histological presentation or a high-grade evolutionary profile. Case Report: We report the case of a 65-year-old patient with no significant medical history, admitted for an increased intracranial pressure syndrome associated with Parinaud's syndrome. Brain magnetic resonance imaging (MRI) revealed a 28x33x39mm pineal region tumor process, causing obstruction of the aqueduct of Sylvius and active triventricular hydrocephalus, which was treated urgently by endoscopic ventriculocisternostomy. The spectroscopic profile was highly suggestive of a high-grade lesion (elevated Choline/NAA ratio). Conversely, stereotactic biopsy revealed an IDH-wildtype astrocytic glial proliferation with a low Ki-67 proliferation index (1% to 3%), contrasting sharply with the radio-clinical aggressiveness. Faced with this anatomo-radiological conflict, the patient was stratified as high-risk according to EORTC/RTOG criteria due to age, critical tumor location, and the partial nature of the resection. Concomitant radio-chemotherapy following an adapted Stupp protocol up to 54 Gy was successfully delivered. Conclusion: This case illustrates the frequent diagnostic conflict in neuro-oncology between a micro-fragmentary histological profile of indolent appearance and highly aggressive multimodal imaging features. Rapid multidisciplinary management with concomitant radio-chemotherapy remains the therapeutic cornerstone to secure local control against these infiltrating entities of the tectal plate.