Penile squamous cell carcinoma: How to identify metastatic inguinal lymph nodes in ¹⁸FDG PET/CT?

Abstract

Penile cancer (PC) is a rare neoplasm accounting for 2% of all cancers among men. With this highly lymphophilic tumor, inguinal node metastases are the most relevant prognostic factor and are associated with decreased survival. The PC evaluation presents a major challenge for therapeutic strategy. Here, we report the case of a 73-year-old man who was discovered with a process of the glans. The histopathological results concluded to be a penile squamous cell carcinoma (PSCC). An MRI scan showed a penile tumor process classified as T4Nx, with the presence of hypertrophic inguinal lymph nodes, which were not clearly suspicious. He was operated by total penectomy followed by perineostomy. The tumor was classified as pT3Nx. An 18F-fluorodeoxyglucose (118FDG) positron emission tomography / computed tomography (PET/CT) was requested to explore the metabolic pattern of these lymph nodes. 18FDG-PET/ CT demonstrated suspicious bilaterally hypermetabolic inguinal nodes, in favor of their metastatic nature and a non-specific hypermetabolism of the penile root. The decision of the urologist was to complete with an inguinal lymphadenectomy.