VIP-Mediated Syndromes: Contrasting Presentations and Multidisciplinary Management of Two Rare Neuroendocrine Tumors

ABSTRACT Vasoactive intestinal peptide (VIP)-secreting tumors are rare neuroendocrine neoplasms that cause severe secretory diarrhea and electrolyte abnormalities. We describe 2 atypical cases requiring multidisciplinary care. One patient had a VIP-secreting pheochromocytoma with elevated VIP and metanephrine levels; symptoms improved after adrenalectomy. The second had a metastatic small intestinal neuroendocrine tumor with persistent VIP-mediated diarrhea despite debulking and somatostatin analog therapy, complicated by anal fissures, trans-sphincteric perianal fistula, and neuropathic pelvic pain. These cases highlight morbidity and potential complications associated with extrapancreatic VIP hypersecretion and the value of coordinated multidisciplinary management to improve outcomes and quality of life.