Gastrointestinal autonomic nerve tumors in the pediatric population: A report of four cases and a review of the literature

BACKGROUND. Gastrointestinal autonomic nerve tumors (GANTs) are a subpopulation of gastrointestinal stromal tumors (GISTs) that are characterized by ultrastructural features resembling enteric autonomic nerve cells, without epithelial, Schwannian, or smooth muscle differentiation. Delineation of the clinicopathologic features of GANT in the pediatric population is lacking. METHODS. The clinicopathologic and outcome data for four pediatric patients with GANT are presented. The data from these patients and four previously reported pediatric patients are summarized and compared with data for GANT in adults. RESULTS. All four cases occurred in females at a mean age of 12.5 years. The primary tumor site was the stomach in all cases, and the mean tumor size was 6.3 cm. Immunocytochemical and ultrastructural examination were essential in distinguishing GANT from GIST in all cases by identifying features of neural origin (neuron specific enolase in all four cases, NFP in three cases, S-100 in two cases, dense core neurosecretory granules in all four cases, and neuritelike processes in all four cases), while failing to identify features of myogenic origin (no desmin, smooth muscle actin, myofilaments, or dense bodies were found in any of the cases). Primary treatment was surgical, with chemotherapy administered to 1 patient at the time of recurrence. All patients are alive after a mean follow-up of 60 months (range, 8 months to 9 years). CONCLUSIONS. Similarities of pediatric GANT to GANT in adults include the need for a high index of suspicion for diagnosis; comparable histopathologic, immunohistochemical, and ultrastructural features; and surgery as the primary therapy. Distinguishing features in children may be a prevalence among females in the second decade, a predominance of smaller gastric tumors, and a positive prognostic value of younger age.