Zollinger-Ellison syndrome associated with a renal gastrinoma in a child.

Renal gastrinoma has not been previously reported. A 12-year-old boy with Zollinger-Ellison syndrome was found to have a renal tumor. No other tumor was detectable by imaging techniques, and selective venous sampling for gastrin showed a significant renal vein to vena cava gradient. Nephrectomy was performed, and examination of the tumor showed typical histologic features of an endocrine tumor. G cells were apparent by electron microscopy, and immunoperoxidase staining for gastrin, neuron-specific enolase, and chromogranin were positive. The gastrin content was unusually low for gastrinomas: 128 pg/g. Following nephrectomy, fasting gastrin and secretin stimulation testing were normal. Basal acidity was reduced by 60% but remained elevated at 39 mmol H +/h (hydrogen ion per hour). We speculate that renal gastrinoma may be characterized by uniquely poor gastrin storage and that curative resection of all gastrinoma tissue may not necessarily be associated with immediate complete suppression of hyperacidity.