Solitary Metastasis Mimicking Glioblastoma in a Patient with Fahr's Disease.

Abstract

Fahr's disease is defined as the accumulation of bilateral idiopathic calcification in the basal ganglia, dentate nucleus, and centrum semiovale. The coexistence of Fahr's disease and intracranial tumors is extremely rare, with only five cases documented in the literature. This study aimed to present a rare case, discussing both similarities and differences with previously reported cases. A 70-year-old female patient presented to our hospital with a progressive headache over the past month. Brain magnetic resonance imaging (MRI) with intravenous contrast was performed for further evaluation. Bilateral basal ganglia, thalamus, and dentate nuclei showed calcifications consistent with Fahr's disease. After excluding toxic, infectious, and endocrine causes of calcification, the patient was diagnosed with Fahr's disease. Magnetic resonance imaging also revealed a midline localized, irregularly contoured, and heterogeneously intense mass with contrast enhancement at the centrum semiovale level, accompanied by peripheral edema. Radiologically, the mass resembled a high-grade glioma or metastasis, and the presence of a lipid peak further suggested metastasis. Based on radiological findings, the patient was diagnosed with brain metastasis of breast carcinoma. The patient received chemotherapy for metastasis, which resulted in substantial regression of the mass. In patients with known Fahr's disease, new-onset headaches and related symptoms should warrant evaluation for possible brain tumors. In these cases, imaging findings should be assessed along with physical examination findings and the patient's medical history to support the diagnostic process.