Xantogranulomatous pyeloneprhritis in children.

Xanthogranulomatous pyelonephritis (XPN) is an unusual and severe form of chronic inflammatory lesion of the kidney, characterised by the destruction of the renal parenchyma and the presence of multinucleated giant cells and lipid-laden macrophages, inflammatory infiltration and intensive renal fibrosis. There are a few cases in the literature which describe the disease in children. The pathomechanism of XPN is poorly understood. Renal obstruction with concomitant urinary tract infection is the most commonly associated pathological finding. The process is typically unilateral and may be focal or diffuse. In both cases, the perirenal infiltration is possible and can be mistaken for common renal neoplasm or inflammatory process. The symptoms are non-specific. Diagnostic imaging techniques with clinical suspicion have enabled XPN to be diagnosed and differentiated from malignancy with a high degree of confidence. Computed tomography (CT) is the mainstay of diagnostic imaging. The definitive diagnosis of XPN is based on pathological assessment after nephrectomy. We review and illustrate the clinical, radiological, surgical and pathological characteristics of XPN in children. All cases shown are surgically and histopathologically proven. TEACHING POINTS: • XPN can present different clinical manifestations. • CT is the mainstay of diagnostic imaging in XPN. • Focal type of XPN should be included in the differential diagnosis of children with a renal mass. • There are no clear guidelines on the management of XPN. • Conservative and surgical treatments should be considered for each individual case. • Histopathological examination confirms the diagnosis and excludes other benign and malign diseases.

Enteric duplication cysts in children: varied presentations, varied imaging findings.

Enteric duplication cysts (EDCs) are rare congenital malformations formed during the embryonic development of the digestive tract. They are usually detected prenatally or in the first years of life. The size, location, type, mucosal pattern and presence of complications produce a varied clinical presentation and different imaging findings. Ultrasonography (US) is the most used imaging method for diagnosis. Magnetic resonance (MR) and computed tomography (CT) are less frequently used, but can be helpful in cases of difficult surgical approach. Conservative surgery is the treatment of choice. Pathology confirms the intestinal origin of the cyst, showing a layer of smooth muscle in the wall and an epithelial lining inside, resembling some part of the gastrointestinal tract (GT). We review the different forms of presentation of the EDCs, showing both the typical and atypical imaging findings with the different imaging techniques. We correlate the imaging findings with the surgical results and the final pathological features. TEACHING POINTS: • EDCs are rare congenital anomalies from the digestive tract with uncertain pathogenesis. • More frequently, diagnosis is antenatal, with most EDCs occurring in the distal ileum. • Ultrasonography is the method of choice for diagnosis of EDCs. • Complicated EDCs can show atypical imaging findings. • Surgery is necessary to avoid complications.