Case report of primary renal pelvis squamous cell carcinoma coexisting with long-standing calculi in left kidney on 18F-FDG PET/CT.

Rationale: Primary renal pelvis squamous cell carcinoma (SCC) is an extremely rare neoplasm. In many patients, the SCC was associated with renal calculi. Patient concerns: A 61-year-old male presented with intermittent pain at the left lumbar region for 3 days. The PET/CT images demonstrated increased F-18-FDG uptake in the upper pole of the left kidney and left renal hilar lymph nodes. Diagnoses: Pathologic examination revealed well-moderately differentiated renal pelvis SCC with lymphatic metastasis. Interventions: The patient underwent a left nephrectomy a few days after the initial staging PET/CT study. Outcomes: No growing lesion or metastasis was observed during a 6-month follow-up. Lessons: Our case demonstrates that F-18-FDG PET/CT is a useful diagnostic tool to evaluate primary renal pelvic SCC and detect metastatic lymph nodes in patients with long-standing calculi.