Primary renal squamous cell carcinoma mimicking the renal cyst: a case report and review of the recent literature

BACKGROUND: Renal squamous cell carcinoma is a rare neoplasm with poor prognosis. Chronic irritation from nephrolithiasis and/or pyelonephritis is the leading cause. CASE PRESENTATION: We described a 51-year-old male patient who was admitted because of left flank pain. Ultrasonography showed a renal cyst containing calculus. However, contrast-enhanced ultrasonography and CT scan revealed an irregular-shaped mass derived from a calculi-containing cyst. Ultrasound guided biopsy confirmed the diagnosis of renal squamous cell carcinoma. The patient refused any further therapeutic management and died six months later. CONCLUSIONS: Our present case emphasizes that the careful diagnostic work-up and use of multiple imaging modalities in cases of unusual renal calculi is quite necessary, since they may carry the risk of co-existing hidden malignancy.