[Drug-resistant genito-urinary rhabdomyosarcoma in children with primary psoas abscess. Apropos of a case].

We report an unusually uncommon case of genitourinary rhabdomyosarcoma in a child which was chemoresistant and complicated by a primary psoas abscess which presented as a pelvic mass associated with an abscess of the right iliac fossa. Ultrasound and CT investigations suggested the diagnosis of a centropelvic tumor which was confirmed at puncture-aspiration. MRI was most contributive giving a precise description of the local extension. Intensive multi-drug chemotherapy would appear to have improved outcome in patients with poor-prognosis Maurer group III tumors. In exceptional cases when no tumor response is obtained, carcinological surgery with large dissection, possibly with adjuvant radiotherapy, is indicated. Percutaneous drainage of the deep psoas abscess is as effective as classical surgery and spares the abdominal wall, particularly important if a second operation should be needed. Multidisciplinary management is required for the treatment of this highly malignant tumor.