paediatrics Brussels 17

Tumor Pathology

• Embryonal – most common, head and neck and genitourinary sites • Sarcoma botryoides (cluster of grapes) – subtype of embryonal, better prognosis, tend to occur in cavities (head and neck, bile duct, vagina, bladder) • Spindle cell – subtype of embryonal, better prognosis, paratesticular and head and neck sites • Alveolar – worse prognosis, extremity and perineal sites, nodal metastasis worse • Pleomorphic – rare in children, described in adult population • Undifferentiated sarcoma – unfavorable histology, used to be included in Intergroup Rhabdomyosarcoma Studies now in COG NRSTS protocols