Cause:Neoplasia from chromosome 11 and 22 translocation
Pathophys:Marrow reticular cells become neoplastic. Usually begins in bony shaft; 40% in axial skeleton
Children 5-15 yr; 2/million children/yr; no correlation w radiation exposure
Sx:Local pain or swelling in bone or joint for months
Si:Fever, tumor mass
Highly malignant; lung mets occur quickly; 60% 5-yr survival w rx, 20% if mets at diagnosis
Lab:
Hem:Elevated wbc
Path:Neoplastic reticular cells with little cytoplasm extending beyond marrow space through haversian system out subperiosteally where elicits periosteal callus reaction
Rx:Radiation to primary w multiagent chemotherapy w vincristine, dactinomycin, doxorubicin, + cyclophosphamide, or others like osfamide and etoposide (Nejm 2003;348:694) to cover micromets