Introduction:Ponephrosis is a severe infection which is defined by the destruction of the renal parenchyma by a suppurative process within the dilated pyelocaliceal cavities. Suspected clinically but his diagnosis is mainly based on imagery. Despite clinical and radiological knowledge, it remains a surprise for the surgeon. The objective of this work is to describe the risk factors, the clinical, paraclinical and histological profile of it. Patients And Methods:We report a retrospective uni-centric study conducted from 02/2018 to 02/17/2020 including all the patients meeting the definition criteria. The data collected on pre-established cards were: age, risk factors, symptomatology, clinical examination data, para-clinical and anato-mopathological examination results Results:Nineteen cases were listed, including 11 men and 08 women (M / F ratio at 1.37). The average age at diagnosis was 40 years (25-75 years). Urolithiasis was the most represented risk factor with 68.4% of the patients (Table 1). Low back pain was the most frequent reason for consultation (52.6%), infectious syndrome in 42.5% of cases. The clinical examination found lumbar contact in 63.1% of cases and a fistula in two cases. In 57.8% of patients, urine culture and pus samples had isolated a germ. Kidney function was impaired in 21% of patients. Ultrasound was diagnosed in 11 cases, but CT confirmed in all cases (Figure 1). All patients were treated with antibiotic therapy followed by subcapsular nephrectomy in 15 cases. Complicated post-operative infection in 5.2% of cases; chronic non-specific pyelonephritis was the most common form in 74% of cases Conclusion: Urolithiasis, obstruction of the upper apparatus and diabetes are the main factors involved. The Euro-scanner plays a crucial role in the diagnosis. Drainage of the excretory pathway completed with cold nephrectomy gives good results. Non-specific chronic pyelonephritis is the most common histological form.

Introduction: Xanthogranulomatous pyelonephritis is a rare and unusual form of chronic pyelonephritis, characterized by the destruction of the renal parenchyma and its replacement by granulomas, abscesses and lipid-laden macrophage collections. Despite clinical and radiological knowledge, it remains a surprise for the surgeon. We are reporting through these two observations the diagnostic difficulties of this condition would lead to an inappropriate treatment as well as to a more severe disease. Observations: Two patients (52 and 57 years old), one of whom is followed fortype 2 diabetes mellitus , were hospitalized for pyonephrosis due to obstructive pyelic and ureteral lithiasis. The pyonephrosis was revealed by a chronic loin pain in a febrile context and confirmed by urogramme showing a destruction of the renal parenchyma, dilated pyelocaliceal cavities with rounded formations of pseudo-tumoral appearance on the lithiasis obstacles. Our initialtreatment consisted of percutaneous nephrostomy under antibiotic covering and secondarily of nephro-ureterectomy without bladder flange performed six weeks later. Histopathology studies showed diffuse xanthogranulomatous pyelonephritis. The postoperative follow up was simple in both cases. Conclusion: Xantogranulomatous pyelonephritis is a rare, severe and chronic form of pyelonephritis whose diagnosis is always histological. Its clinical picture is no specific, hence the problem is that it poses achalleng of differential diagnosis with renal tumors and urogenital tuberculosis. Its treatment is based on nephrectomy.