GENITOURINARY RHABDOMYOSARCOMA IN CHILDREN - RADIOLOGIC-PATHOLOGICAL CORRELATION

Rhabdomyosarcoma is the most common tumor of the lower genitourinary t ract in children in the first 2 decades of life, Most cases of genitou rinary rhabdomyosarcoma are of the embryonal histologic subtype and in clude tumors of the bladder, prostate, testes and paratesticular sites , penis, perineum, vagina, and uterus, The natural history, pattern of metastatic spread, treatment, and prognosis of childhood rhabdomyosar coma vary with the anatomic site of the lesion, In children with rhabd omyosarcoma of the bladder or prostate, presenting signs and symptoms include urinary or fecal retention, dysuria, urinary tract infection, and hematuria, Paratesticular rhabdomyosarcoma produces painless scrot al swelling, which may be ignored until the tumor has reached a large size, Vaginal tumors may manifest as a prolapsing mass in the introitu s, Radiologic studies of children With genitourinary rhabdomyosarcoma reflect the nonspecific gross features of the tumor, which may be ill defined with infiltrative margins or well circumscribed by a pseudocap sule of compressed tissue, The botryoid variant of embryonal rhabdomyo sarcoma results when submucosal tumor produces a polypoid mass resembl ing a cluster of grapes within a hollow structure, Botryoid morphology is characteristic, but not specific, for rhabdomyosarcoma within the vagina or urinary bladder, since yolk sac tumor and ''tumoral'' cystit is may have a similar appearance. Invasion of adjacent structures by t he primary tumor may make the precise anatomic origin of genitourinary rhabdomyosarcoma difficult to determine on cross-sectional images, Re cent refinements in multidisciplinary therapeutic regimens combining c hemotherapy, radiation therapy, and surgery have dramatically improved outcome for children with genitourinary rhabdomyosarcoma, Diagnostic imaging plays an important role in monitoring response to therapy.