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

Atypical presentations of UTUC: a case report of three patients

Background

Upper tract urothelial carcinoma (UTUC) is a rare clinical condition primarily characterized by symptoms such as gross or microscopic hematuria, flank pain, and renal colic. Although computed tomography urography (CTU) is currently the most accurate imaging modality for diagnosis, atypical presentations and physical examination findings can sometimes obscure lesions, posing diagnostic challenges.

Case presentation

In this report, three patients exhibited atypical symptoms, sharing a common complaint of flank pain. Notably, the first patient, who had recently undergone laparoscopic right duplex nephrectomy, presented with microscopic hematuria, whereas the other two did not show any gross or microscopic hematuria. Computed tomography urography revealed hydronephrosis and infection without significant renal pelvic space-occupying lesions, with persistently elevated white blood cell (WBC) counts, but no fever. These atypical clinical presentations confounded clinicians, delaying the diagnosis of upper tract urothelial carcinoma until postoperative pathological examination for the first two patients and resulting in advanced-stage diagnosis for the third patient. Postoperative pathology confirmed high-grade invasive upper tract urothelial carcinoma in all three patients.

Conclusion

Upper tract urothelial carcinoma can manifest atypically without hematuria and may be challenging to visualize on computed tomography urography, potentially leading to misdiagnosis. Therefore, clinicians should maintain a high level of suspicion for malignant tumors when patients exhibit hydronephrosis, infection on imaging, and persistently elevated white blood cell counts without fever, even in the absence of typical signs of upper urothelial carcinoma on computed tomography urography.

Concurrent Xanthogranulomatous Pyelonephritis and Upper Urinary Tract Transitional Cell Carcinoma

A 37-year-old male with a history of chronic nephrolithiasis presented to the ED with gross hematuria, clot retention, and right flank pain. The patient had radiological findings of perinephric stranding, marked hydronephrosis, and marked thinning of the right renal parenchyma on computed tomography (CT), all suggestive of xanthogranulomatous pyelonephritis (XGP). The specimen following radical nephrectomy revealed urothelial carcinoma (UC) in a background of XGP but with no evidence of spread to regional lymph nodes. Follow-up imaging revealed hypodense lesions in the liver which demonstrated UC on biopsy. This is the first reported case of a young patient presenting with such an advanced stage of UC in the setting of XGP. It illustrates the link between inflammatory processes of the kidney and malignancy of the upper urinary tract.

Unusual case of urothelial carcinoma disguised as xanthogranulomatous pyelonephritis and causing reno-colic fistula: Case report and review of literature

Xanthogranulomatous pyelonephritis is a rare and aggressive form of chronic pyelonephritis, it can occur at all age groups but is more common in women than in men, supposedly relating to the increased incidence of urinary tract infections and chronic nephrolithiasis in woman. Computed tomography (CT) findings are very helpful in making the correct diagnosis, but the definitive diagnosis is still based on histology, as there are many differential diagnoses such as renal cell carcinoma and renal tuberculosis. The complications of this type of pyelonephritis are due to the involvement of adjacent organs. The most frequent ones are Psoas abscess, perinephric abscess, and sepsis. Nephrocutaneous and renocolic fistulas are less common. We report a case of a 61-year-old male, who presented to emergency for left-sided lumbar pain for whom radiological investigations confirmed a renocolic fistula complicating xanthogranulomatous pyelonephritis. The diagnosis of XGP was proven by histopathological examination of the nephrectomy specimen slides, but there was also association with an underlying malignant squamous differentiation consistent with urothelial carcinoma, which was not evident on CT. XGP is a rare variant of chronic pyelonephritis with known imaging features. The treatment of choice is nephrectomy and histopathological examination is required for final diagnosis, as there may be associated renal malignancy.

A case of xanthogranulomatous pyelonephritis leading to nephrobronchial fistula and lung abscess: does it always manifest with respiratory symptoms?

Xanthogranulomatous pyelonephritis (XGP) is a serious manifestation of chronic kidney inflammation that can expand to adjacent structures. Here we report a case of XGP extending beyond the diaphragm through a nephrobronchial fistula to form a lung abscess in a 70-year-old man. The patient presented to the emergency department with severe right flank colic pain, nausea, vomiting and nonspecific constitutional symptoms for the past 4 months. Although the patient did not complain of any respiratory symptoms, initial evaluations revealed severe right-sided hydroureteronephrosis with debris, as well as an area of infiltration in the right lung lower lobe (RLL). Given the patient's condition, a thorough work-up was expedited to investigate the potential association between the symptoms. Ultimately, a diagnosis of XGP with expansion to the RLL through the right hemidiaphragm was developed. A right radical nephrectomy, right lower lobectomy and right hemidiaphragm resection were carried out. XGP was confirmed on the basis of the pathological evaluation of the resected specimens.

Xanthogranulomatous Pyelonephritis and Its Differential Diagnoses: An In-Depth Case Review

Xanthogranulomatous pyelonephritis is a rare chronic infectious process of the kidney, which has been described in three different forms: diffuse, segmental, and focal. It is also known as the great simulator since its clinical, radiological, and histopathological manifestations tend to be confused with other entities. We describe a case of a 55-year-old male patient with two months of clinical manifestations characterized by a 7x7-cm palpable mass in his right lumbar region, which was hot and painful upon touch and increasing in size. This article aims to present a case of xanthogranulomatous pyelonephritis and compare it with its primary differential diagnoses. It is evident that despite the condition being considered a simulating pathology, some key differences can be found to identify and distinguish it.

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.

Focal Xanthogranulomatous Pyelonephritis with Pulmonary Lesions on the Background of Type Two Diabetes Mellitus

Focal Xanthogranulomatous pyelonephritis is a rare chronic inflammatory condition of kidneys which usually is associated with postrenal obstruction or renal stone leading to chronic bacterial infection and eventually chronic glomerular inflammation. About 90% of cases are of the diffuse type and associated with staghorn renal calculi. The case presented in this paper is of the focal type in a 58-year-old diabetic female. Interestingly she did not have symptoms or laboratory presentation of chronic renal bacterial infection except for elevated ESR. She sought medical attention due to severe pulmonary infection of the background of morbid obesity. Imaging studies revealed several pulmonary lesions and a large mass of the right kidney which was indistinguishable from renal malignancy. After surgical resection of the right kidney, the lesion is pathologically diagnosed to be a focal Xanthogranulomatous pyelonephritis. The pulmonary lesions were spontaneously resolved about three months following right nephrectomy.