CALCITONIN-SECRETING TUMORS OF THE PANCREAS - ABOUT 6 CASES

Calcitonin release has rarely been reported in patients (pts) with neu roendocrine pancreatic tumors (NPT). The aim of this study was to desc ribe the characteristics of calcitonin-secreting tumors (CST) of the p ancreas. Serum calcitonin determination was part of the prospective ev aluation of 66 pts with NPT referred to our institution over a 3-year period. Six pts (9%) had elevated calcitonin levels [at least twice th e limit of the normal value (N)]. Abdominal ultrasonography, computed tomography scan, and endoscopic ultrasound were performed to identify the primary tumor(s) and metastases. Immunostaining using anticalciton in and other antibodies was performed on the surgical resection specim en (four pts) or biopsy of liver metastases (two pts). Three of the si x pts (four males, two females; median age, 51.5 years) had diarrhea. Serum calcitonin levels (median, range) were 17.5 N (6N-40N). Slight e levations in serum somatostatin (1.2N-2.3N) were associated in three p ts. Pancreatic tumors were single in five of six pts and evenly distri buted in the head and in the tail. Five pts had metastases, mainly in the liver. Multiple endocrine neoplasia type I was present in one pt. Immunostaining using calcitonin and somatostatin antibodies was positi ve in four pts each, respectively, and areas that were positive for on e peptide were negative for the other. Diarrhea disappeared in the two pts who responded to treatment of the tumors (s). Three of the four p ts with liver metastases died from tumor progression after 2, 10, and 24 months, respectively. CST of the pancreas are often malignant and c an be considered as functional in half of the cases, irrespective of t he serum calcitonin levels. Somatostatin secretion is often associated . Although rare, calcitonin secretion should be investigated in NPT pt s presenting with diarrhea that cannot be explained by an increase in other hormone levels or in patients with nonfunctioning NPT.