Peripheral neurogenic tumors of the soft tissues in children and adolescents: a clinicopathologic study of 139 cases.

A review of over 900 soft tissue neoplasms in children and adolescents revealed 139 neurogenic tumors in 122 patients from newborn to 20 years of age, which had been accessioned in a 25-year period. Based upon clinicopathologic criteria, 84 (60%) tumors were regarded as unequivocally benign or borderline and the remaining 55 (40%) were malignant. The average age at diagnosis for the entire series was 10 years; the sex distribution was approximately equal; and the trunk (66, 48%) was the most frequent topographic site, followed by the head and neck (39, 29%) and extremities (31, 23%). Eighteen tumors (13%) were recognized at birth. Twenty-one patients (17%) had the stigmata of von Recklinghausen's neurofibromatosis (VRN). Neurofibromas and cellular peripheral nerve sheath tumors accounted for 43% (60 cases) of the diagnoses; these 60 neoplasms occurred in 41 patients, 12 of whom had VRN. The second largest category of neoplasms (38 cases, 28%) was the primitive neuroectodermal tumor (PNET) including the subset of "malignant small cell tumor of thoracopulmonary origin" or Askin tumor. The PNETs other than the Askin tumor (26 cases) presented mainly on the trunk (63%) and head and neck region (33%), showed a male predilection (58%) and had a mean age at diagnosis of 7 years. Askin tumors (12 cases) were, by definition, confined to the chest wall or thoracic cavity, showed a female predilection (71%), and presented in the second decade (82%, mean age 14 years). There were 16 (11%) malignant peripheral nerve sheath tumors, seven of which occurred in children with VRN. Six other categories of neurogenic tumors constituted the remaining cases. Our findings indicate that neurogenic neoplasms are an important nosologic group of soft tissue tumors in the pediatric population.