Malignant ectomesenchymoma. Case report and review of the literature.

Malignant ectomesenchymoma is an uncommon neoplasm composed of neuroectodermal elements and one or more mesenchymal neoplastic elements. It is believed to arise from remnants of migratory neural crest cells (ectomesenchyme). The authors report the clinical and pathological findings of a 3-year-old girl with malignant ectomesenchymoma of the CNS. Embryogenesis of this tumor is discussed, and a review of the literature with 39 other cases is done.