Intracranial Micrococcus Luteus Infection Mimicking Brain Metastases on 18 F-FDG PET/CT.

An 86-year-old man presented with slurred speech and right lower limb shaking for 1 month. Initial brain MRI revealed an abnormal signal lesion in the left parietal lobe with peripheral parenchymal edema, and brain metastases were suspected. Subsequent PET/CT showed increased focal FDG uptake in the left parietal lobe, accompanied by bands of surrounding brain parenchyma edema. No other abnormal lesions were observed on 18 F-FDG PET/CT except for increased inflammatory lymph node activity in the left hilar region. Finally, the cerebrospinal fluid puncture culture showed a Micrococcus luteus infection. Therefore, the clinical diagnosis was infectious lesions.