Introduction: Squamous cell carcinoma (SCC) comprises 0.5%–15% of tumours in the renal pelvis and ureter. SCC after percutaneous nephrolithotomy (PCNL) for staghorn calculus is a rare entity with only five cases reported. Tumour spreading along the tract after PCNL is even more uncommon with only one case reported. We report a case of SCC of the renal pelvis and tract of PCNL extending upto skin over the flank and review the literature, demonstrate surgical technique.

Case report: A 54-year-old gentleman was diagnosed with right pelvic staghorn lithiasis due to flank pain and confirmed on a non-contrast computed tomography (CT) scan. He underwent PCNL in two stages over 2 weeks apart. There was no suspicious lesion after the complete removal of the stone. Due to persistent right flank pain and hematuria after 3 months, the patient was evaluated with a contrast CT and magnetic resonance imaging (MRI) which revealed an enhancing lesion over the right kidney extending from the renal pelvis to the PCNL tract associated with retrocaval, aortocaval and precaval nodes. CT-guided biopsy of the mass was performed diagnosing a high-grade carcinoma with squamous differentiation. Urine cytology showed dysplastic cells. Diethylenetriaminepentaacetic acid study revealed a low glomerular filtration rate of 20 mL/min in the right kidney. There were no metastases elsewhere. We performed radical nephrectomy along with excision of the PCNL tracts, skin and flank muscles excision with template-based retroperitoneal lymph node dissection. Finally, we use a mesh for reconstruction.

Conclusion: Long-standing staghorn calculus may harbor SCC of the renal pelvis which is undiagnosed preoperatively probably due to chronic irritation. Complete surgical excision with negative margins (R0) is the only option to cure as demonstrated in this case.