NCIt definition : An aggressive malignant mesenchymal neoplasm occurring in children. It is characterized
by the presence of round cells with myoblastic differentiation, and a fibrovascular
stroma resembling an alveolar growth pattern.;
Alternative definition : NICHD: A histologic subset of rhabdomyosarcoma consisting of a malignant mesenchymal
neoplasm occurring in children. It is characterized by the presence of round cells
with myoblastic differentiation, and a fibrovascular stroma resembling an alveolar
growth pattern.;