MUC5AC and von Hippel-Lindau disease: For the patients who underwent a biopsy (or fine needle aspiration), the indications for surgery included 14 patients with malignant lesions, 25 patients with atypical cells, 13 patients with mucin ±, an elevated CEA, and 4 patients with specific indications including (1) main duct IPMN; (2) an elevated CA19-9; (3) two separate pancreatic tumors in a patient with Von Hippel-Lindau disease (one serous, one pancreatic neuroendocrine tumor); and (4) patient symptoms.