Staghorn calculi and xanthogranulomatous pyelonephritis associated with transitional cell carcinoma

Upper tract transitional cell carcinoma clinically mimicking inflammatory renal pathology: A report of three cases

Upper tract urothelial carcinoma (UTUC) of the renal pelvis and the ureter is incidentally detected in a small proportion of cases. However, the majority of UTUC cases present with hematuria, flank pain, and clot colic. Typical imaging features include hydronephrosis of the kidney (s) due to obstruction by the mass with a soft-tissue lesion that typically shows low-grade enhancement with or without a filling defect. Rarely, such a tumor may present with signs and symptoms mimicking an inflammatory or infective pathology of the kidney and is diagnosed only on biopsy or on nephrectomy. We present three such patients and cite another similar case we have published earlier. All three of these patients presented with signs and symptoms of an obstructed infected kidney with long-standing renal calculi and a forgotten DJ stent in one instance. Nephrectomy for the presumed infected kidney in all three cases revealed high-grade UTUC. In patients presenting with equivocal findings on cross-sectional imaging with a history of renal calculi or foreign bodies, we should have a high index of suspicion for malignancy.

High-grade transitional cell carcinoma masquerading as a xanthogranulomatous pyelonephritis and perinephric abscess

Xanthogranulomatous pyelonephritis (XGPN) is an atypical long-term pyelonephritis with destruction of renal parenchyma and a long-term inflammatory infiltrate of macrophages. Reported presentations of transitional cell carcinoma (TCC) are different. A 73-year-old woman presented with loin pain, prostration, and fever. Computed tomography scan revealed poor cortical enhancement of the kidney, but some of the images bore resemblance to the characteristic “bear's paw” sign, consistent with XGPN with a 7-cm perinephric collection. She was provisionally diagnosed as severe acute pyelonephritis, possibly XGPN, with abscess. In view of the poor clinical condition, decision was made to perform nephrectomy. Histology revealed a G3pT4 high grade TCC with perineural and vascular invasion and reactive xanthogranulomatous inflammatory response. There are few reports of concomitant XGPN and TCC affecting the kidney. However, there has not been any mention of XGPN and TCC presenting as acute pyelonephritis and perinephric abscess so far.