[Pseudotumorous focal xanthogranulomatous pyelonephritis in children. Apropos of a case].

Xanthogranulomatous pyelonephritis is a particular form of chronic pyelonephritis. It is observed less frequently in children and can sometimes present with a focal pseudoneoplastic appearance. An 11-year-old child was admitted with abdominal pain, alteration of the general state and weight loss without fever or palpable mass. Medical imaging was unable to distinguish between malignant renal tumour or tuberculosis. The diagnosis was confirmed by the inflammatory and purulent appearance of the mass and histopathological examination of the biopsy fragment. Percutaneous drainage of the abscess, combined with antibiotics provided marked improvement. Despite its rarity and its nonspecific clinical features, focal xanthogranulomatous pyelonephritis must be considered in order to propose conservative treatment.