Inflammatory breast cancer with refractory diarrhea: a case report.

Excessive amounts of vasoactive intestinal polypeptide (VIP) cause a special clinical syndrome characterized by secretory diarrhea, hypokalemia and dehydration. A careful clinical workup of a 62-year-old female admitted for refractory diarrhea revealed a neglected inflammatory right breast ductal carcinoma with VIP hypersecretion without any localized abdominal tumor. Immunohistochemistry of the breast biopsy showed neuroendocrine characteristics with positive staining for VIP, and Octreotide scan showed hyperfixation to the right breast and axilla.