A rare case of renal squamous cell carcinoma presenting with psoas sign

INTRODUCTION: Renal cancer is a relatively common form of cancer; however, squamous cell carcinoma of the kidney is extremely rare and it carries poor prognosis. CLINICAL PRESENTATION: We present a rare case of renal squamous cell carcinoma that was manifested with the psoas sign in a patient with a history of chronic staghorn calculus. DISCUSSION: Squamous cell carcinoma of kidney is rare and more invasive. Even though many risk factors have been identified, staghorn renal calculi with chronic infection have a higher incidence of renal squamous cell carcinoma (SCC). Squamous cell carcinoma (SCC) has a wider range of atypical presentations; the psoas sign is not commonly reported in other literature. Due to the lack of reporting and sufficient knowledge, there are currently no established management guidelines. Despite advancements in contemporary medicine, the survival rate of renal SCC remains remarkably low, necessitating further research to develop a standardized treatment protocol. CONCLUSION: Primary renal SCCs are rare tumors and exhibit a strong association with renal stones, requiring prompt assessment and treatment of renal stones in affected patients. Despite their aggressiveness and poor prognosis, timely intervention is crucial.