Xanthogranulomatous pyelonephritis is a morphologic variant of pyelonephritis. Focal disease is very rare and can be misdiagnosed.

Rhabdomyomas are benign rumors of striated muscle. They are distinguished by topographic data : cardiac or genital and by histological criteria :foetal or adult type. The foetal type is the most heterogeneous, with either a majority of immature cells or a mixture of maturing elements. This diversity has led to distinguish immature (or standard) foetal Rhabdomyomas from intermediate foetal Rhabdomyomas. One observation of this last type is reported. The authors highlight the essential characteristics of foetal Rhabdomyomas. however the exact meaning remains unclear: an anomaly in the differentiation of the striated muscle ? or a true tumoral process through generic anomaly ?.

Rhabdomyomas are benign tumors of striated muscle. They are distinguished by topographic data: cardiac or genital and by histological criteria: foetal or adult type. The foetal type is the most heterogeneous, with either a majority of immature cells or a mixture of maturing elements. This diversity has led to distinguish immature (or standard) foetal Rhabdomyomas from intermediate foetal Rhabdomyomas. One observation of this last type is reported. The authors highlight the essential characteristics of foetal Rhabdomyomas, however the exact meaning remains unclear: an anomaly in the differentiation of the striated muscle? or a true tumoral process through genetic anomaly?

Arthritis-like pain about the joint and evidence of inflammation are the main clinical features, The erythrocyte sedimentation rate is elevated. Radiographs show lucent bands in the metaphysis. The soft tissues are normal by ultrasonography and magnetic resonance imaging. Microbiological tests are negative. The combination of joint pain, inflammation, and lucent metaphyseal bands is sufficiently suggestive as to make a biopsy unnecessary, The disease runs its course over several months or years, with sclerosis gradually replacing the metaphyseal lucencies, inflammatory nonsuppurative metaphyseal osteomyelitis imitating inflammatory arthritis is rare but easy to recognize based an its characteristic features and outcome. Administration of antiinflammatory drugs is the mainstay of therapy, The efficacy of antimicrobial therapy is unproven.

Cette affection rare est caracterisee par le developpement de tumeurs multiples dans le tissu conjonctif et de lesions osseuses. Elles peuvent etre associees a des localisations viscerales dont le pronostic est severe. La cellule predominante au sein de ces tumeurs est le myofibroblaste. Les atteintes du conjonctif peuvent etre spontanement regressives ou necessiter une exerese chirurgicale large pour eviter les recidives. Pour les formes viscerales, le recours classique est la chirurgie, mais la chimiotherapie s'est averee efficace ces dernieres annees.

Les tumeurs osseuses a cellules geantes sont rares chez l'enfant et de siege typiquement metaphysaire, contrairement au siege epiphysaire de l'adulte. Les auteurs en rapportent 5 observations : deux au femur, deux au perone, une au tibia. Le diagnostic radiologique repose sur la radiographie conventionnelle completee par l'examen scanographique. Le diagnostic differentiel se pose avec le kyste osseux anevrysmal et, dans les formes metaphyso-epiphysaires, on peut avoir a discuter du chondroblastome. Le traitement de choix est le curetage suivi de comblement mais on peut etre parfois contraint a des resections plus delabrantes.

Giant cell tumor of bone rarely affects children, in whom it is usually located in a metaphysis in contrast to the predominantly epiphyseal localization in adults, Five cases are reported, two at the femur, two at the fibula and one at the tibia, Plain film radiography and computed tomography are the most informative imaging studies, The differential diagnosis is with aneurysmal bone cyst and, in metaphyseal-epiphyseal forms, with chondroblastoma. Treatment usually consists in curettage of the tumor followed by filling of the cavity; however, more extensive resection is required in some cases.

Magnetic resonance imaging (MRI) findings in 12 patients with biopsy-proven eosinophilic granuloma were studied retrospectively. Signal intensity was variable on TI images and increased on T2 images and after gadolinium injection. Magnetic resonance imaging identified all the granulomas, as well as accompanying bone marrow and soft tissue changes. In all 12 cases, the lesion appeared larger on MRI displays than on plain roentgenograms. MRI findings had low specificity and consistently tended to overestimate tumor spread, especially when a long limb bone was affected. Chemotherapy was followed by changes in the size and shape of MRT lesions (loss of the high-intensity signal on T2 images and after gadolinium) suggestive of a favorable response to treatment.

A case of metastatic extrarenal, retroperitoneal Wilms tumor developed in the right adrenal gland in a four-year-old boy is reported. Wilms tumor should be considered in pediatric patients with a juxtarenal retroperitoneal mass and pulmonary and mediastinal metastases. Computed tomography and ultrasonography are valuable for evaluating tumor spread. Preoperative chemotherapy is helpful, The locations, pathologic features, and etiology of Wilms tum are discussed based on a review of the literature.

Nous avons etudie retrospectivement l'aspect IRM de 12 granulomes eosinophiles prouves par biopsie osseuse. Leur signal etait variable en ponderation T1, hyperintense en ponderation T2 ainsi qu'apres injection de gadolinium. L'IRM s'est revelee particulierement performante pour identifier toutes les lesions ainsi que les modifications de la moelle osseuse et des parties molles avoisinantes qui les accompagnaient. Dans tous les cas, les lesions apparaissaient plus etendues que sur le cliche standard. La specificite des images restait faible et le risque de surestimation de l'extension tumorale constant, principalement dans les formes des os longs des membres. Les lesions traitees par chimiotherapie presentaient des modifications de forme et d'aspect (perte du signal intense en T2 et apres contraste), qui pourraient presager d'une reponse favorable au traitement.

Un cas de nephroblastome extra-renal retroperitoneal cortico-surrenalien droit metastase chez un enfant de quatre ans est rapporte. La necessite d'evoquer ce diagnostic devant une masse retroperitoneale juxtarenale avec metastases chez l'enfant, le bilan d'extension de la tumeur par T.D.M et echographie et les avantages d'une chimiotherapie pre-operatoire sont evoques a propos de ce cas. Les localisations, l'anatomopathologie et l'etiologie de cette tumeur sont abordees a travers une revue de la litterature.

L'echographie permet generalement de porter le diagnostic de nephroblastome et d'apprecier l'eventuelle extension aux organes voisins et a la veine cave inferieure. Toutefois, un certain nombre d'equipes completent cette exploration par une TDM en preoperatoire qui fournit une cartographie tres precise des lesions. L'echographie permet egalement de suivre l'efficacite de la chimiotherapie. Apres intervention, ces examens permettent de juger des resultats dont la qualite est fonction de la variete histologique. Les autres explorations sont reservees a des situations tres ponctuelles