Bilateral Renal Metastases from Lung Adenocarcinoma Revealed on ¹⁸F-FDG PET/CT

Lung cancer is the leading cause of cancer-related deaths worldwide. While metastasis to distant organs is commonly described, renal metastasis remains rare and uncommon. In this paper, we present the case of a 53-year-old man with a history of left apical lung adenocarcinoma who underwent fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (CT) for suspected recurrence. The scan revealed a recurrent pulmonary mass with metastatic spread, notably showing intense bilateral focal FDG uptake in the kidneys. A metastatic origin was suspected and subsequently confirmed by CT-guided renal biopsy. Although rare and typically observed in advanced stages of the disease, this case underscores the importance of carefully evaluating focal FDG uptake in the renal cortex to ensure accurate staging and optimal management of oncologic patients.