Congenital spindle cell rhabdomyosarcoma of the urinary bladder

Spindle cell rhabdomyosarcoma is a recently described variant of embryonal rhabdomyosarcoma that carries a relatively favorable prognosis when compare d with other types of rhabdomyosarcoma. We report the first case of a conge nital spindle cell rhabdomyosarcoma in the urinary bladder of a newborn. Th e patient was diagnosed with obstructive uropathy and cystic kidneys in the antenatal period. The tumor was compose primarily of mature strap-shaped r habdomyoblasts with cross-striations; it involved focally the full thicknes s of the bladder mall. No extension into adjacent organs or distant metasta ses were identified. The patient died of complications of urinary tract obs truction shortly after birth.