Extensive Dural Metastasis as Initial Presentation of Metastatic Prostate Cancer: A Case Report With Durable Disease Control Following Multimodal Treatment

Central nervous system involvement in prostate cancer is rare, particularly in the form of dural or pachymeningeal metastases. We report the case of a 72‐year‐old man presenting with visual disturbances without hemianopsia, and right‐sided headache since several weeks caused by an extensive right temporal dural‐based lesion with intracranial extension. A minimally invasive frontotemporal burr‐hole biopsy was performed for histopathological clarification. Histological and immunohistochemical analyses confirmed metastatic prostatic adenocarcinoma with expression of cytokeratin 8, NKX3.1, PSA, and PSMA. Subsequent systemic staging demonstrated metastatic castration‐sensitive prostate cancer with pulmonary, lymphatic, and extensive osseous metastases. The patient underwent focal radiotherapy (36 Gy in 12 fractions) to the dural lesion and systemic treatment with androgen deprivation therapy and enzalutamide. Due to dizziness and sweating, enzalutamide dosage was reduced from 160 to 80 mg/day with maintained therapeutic response. At approximately 15 months of follow‐up, the patient remained neurologically stable with durable local disease control on cranial MRI, marked biochemical response (PSA decline from 177 to 0.6 ng/mL), and no evidence of systemic progression. This case highlights the importance of considering metastatic prostate cancer in the differential diagnosis of dural‐based intracranial lesions in elderly men and demonstrates that individualized multimodal treatment can achieve durable disease control even in rare metastatic presentations.