Neuromuscular hamartoma--a benign "triton tumor" composed of mature neural and striated muscle elements

Two infants with benign, hamartomatous tumors composed of well-differentiated and intimately admixed neural and striated muscle components are presented. Their histogenesis is discussed in light of embryologic concepts of the derivation of mesenchymal tissues from neuroectoderm and in reference to previous reports of benign and malignant tumors of the nervous system with striated muscle components.