Synchronous glioblastoma and pituitary adenoma: Coincidence or shared genetic predisposition? A case report and comprehensive literature review

Background: The synchronous occurrence of pathologically distinct primary intracranial tumors is an exceptionally rare clinical entity. The coexistence of an isocitrate dehydrogenase (IDH)-wild-type glioblastoma (GBM) and a pituitary adenoma poses significant diagnostic and therapeutic challenges, with only six previously reported cases in the medical literature; seven, including the present patient. Case Description: We report a 45-year-old man who presented with progressive visual decline and headache. Magnetic resonance imaging demonstrated two separate, distinct lesions: A sellar mass consistent with a pituitary macroadenoma and a left frontal intra-axial lesion suspicious for high-grade glioma. The patient underwent staged surgical management consisting of an endoscopic endonasal transsphenoidal resection of the sellar lesion, followed by a frontal craniotomy for the intra-axial mass. Histopathological examination confirmed a pituitary transcription factor 1-lineage densely granulated lactotroph adenoma (pituitary neuroendocrine tumor) and an IDH-wildtype GBM (World Health Organization grade 4). Adjuvant radiotherapy and temozolomide chemotherapy were administered. GBM recurrence was detected 12 months after surgery, and the patient died 20 months after the initial diagnosis. Conclusion: The coexistence of GBM and pituitary adenoma is exceedingly rare. Including the present patient, only seven cases have been reported to date. Further clinical and molecular investigations are required to clarify whether this association represents a coincidental occurrence or reflects an underlying biological relationship.