Unusual peptide-secreting tumors in adolescents and children.

Endocrine tumors of the pancreas and intestine are uncommon but challenging lesions. Those tumors that arise in the pancreas are typically derived from one of the various cell types of the islet of Langerhans and secrete the peptide associated with the cell type. In general, the primary tumors are small, relatively slow growing, and many are benign. However, certain tumors are malignant, more aggressive, and metastasize early, such as gastrinomas, glucagonomas, and VIPomas. Many of these tumors can be multicentric, and some may arise in the duodenum of small intestines. Tumors that arise more often in the intestine are carcinoids and VIPomas. The endocrine effects of many of these tumors such as VIPomas or gastrinomas can be life-threatening. A markedly elevated level of a specific peptide will generally be sufficient to establish the diagnosis. Often, the greatest challenge is localizing the tumor(s). The only opportunity for cure is complete surgical excision. Palliation can be accompanied through tumor reduction, surgically of with antineoplastic agents (eg, doxorubicin and 5-fluorouracil). Palliation from symptoms also can be accomplished by blockade of the peptide's secretion of effects. The prognosis is variable and depends on cell type, resectability, and presence of metastases.