Epileptogenic Brain Metastasis Early Positive on 18FDG PET/CT Compared to MRI

A 61-year-old woman currently undergoing first-line treatment by immunochemotherapy for metastatic small cell lung carcinoma (SCLC) presented for consultation with symptoms of permanent and isolated tremor of the right upper limb. Brain MRI was normal. The ¹⁸ F-FDG PET/CT showed an isolated sub-scan hypermetabolism in the left precentral gyrus. Two weeks later, a new MRI was performed, showing cortical contrast enhancement correlated with the PET images. This case shows that PET/CT can be useful in detecting symptomatic metastatic lesions in cases where MRI is normal.