Vasoactive Intestinal Peptide-Secreting Pheochromocytoma: A Case Report and Review of Literature

OBJECTIVE: To describe a case of composite vasoactive intestinal peptide (VIP)-secreting pheochromocytoma and review literature to provide insight into the various presentations and potential management of these rare tumors. CASE REPORT: A 64-year-old male patient presented with hypertensive emergency and coronary demand ischemia with development of watery diarrhea, hypokalemia, and achlorhydria syndrome. Serum and urine studies demonstrated elevated metanephrine and VIP levels. Definitive surgical resection resolved symptoms and normalized laboratory values. Pathologic examination of the specimen revealed pheochromocytoma with a Pheochromocytoma of the Adrenal gland Scaled Score of 4 and patchy expression of VIP. DISCUSSION: Given the different actions of hormones that can be secreted by these composite tumors, we suggest that pheochromocytomas with diversified secretory capabilities may be an underrecognized clinical entity. Localized disease is often amenable to surgical resection, although management of metastatic disease is not well established due to the rarity of these tumors and lack of randomized trials. CONCLUSION: In patients presenting with diarrhea of unclear etiology or the suggestion of secondary hypertension, assessment for a possible neuroendocrine tumor may be prudent. If an adrenal mass is discovered but the patient exhibits atypical symptoms of catecholamine excess, a diagnosis of composite pheochromocytoma with multisecretory properties should be considered.