A Rare Case of Primary Squamous Cell Urachal Carcinoma Staged with 18F-FDG PET/CT

Primary squamous cell urachal carcinoma is an exceedingly rare epithelial neoplasm and an aggressive malignancy, originating from the urachal remnants. In contrast to mucinous adenocarcinoma, the most common histological type, squamous cell urachal carcinoma demonstrates high 2-deoxy-2-¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake, making ¹⁸F-FDG positron emission tomography/computed tomography (PET/CT) a valuable tool for evaluating regional lymph node involvement and detecting distant metastases. Optimal surgical management, the need for systemic therapy, and the overall prognosis are largely determined by accurate clinical staging, which is mainly based on the widely recognized Sheldon and Mayo classifications. We present a rare case of primary squamous cell urachal carcinoma on ¹⁸F-FDG PET/CT in a young woman, with correlation to surgical and histopathological findings.