Pathology of rhabdomyosarcoma: experience of the Intergroup Rhabdomyosarcoma Study, 1972-78.

A preliminary evaluation of histologic subtypes of rhabdomyosarcoma has shown that the alveolar pattern is associated with a significantly shorter survival when the patient has localized disease that has been completely excised at diagnosis. New histologic variants of undifferentiated sarcoma have been identified, but the clinical significance of these variants remains to be determined. Study of postmortem data of children placed on the Intergroup Rhabdomyosarcoma Study has shown several important clinical facts: Patients with head and neck parameningeal primary sites have a high incidence of treatment failures because the tumor extended into the adjacent central nervous system, with or without spinal fluid spread. Primary sites in the extremities and genitourinary tract are associated with an increased rate of regional lymph node spread. Systematic study of more patients is required before this association can be fully evaluated.