Immunocytochemical stains for various
pancreatic hormones were performed on 77 pancreatic endocrine
tumors from 59 patients [17 with
hypoglycemia, three with
glucagonoma syndrome, 18 were
Zollinger-Ellison syndrome, six with
WDHA (
watery, diarrhea, hypokalemia, and achlorhydria) syndrome and 15 without endocrine symptoms]. In all
tumors that caused either
hypoglycemia or
glucagonoma syndrome,
insulin and
glucagon were respectively identified. On the other hand, only 10
tumors from 18 patients with
Zollinger-Ellison syndrome were positive for
gastrin, and only four of six patients with
WDHA syndrome had a vasoactive intestinal
peptides-positive
tumor. Ten of 15 clinically silent
tumors contained
hormone-producing cells but without a consistent pattern. Ten
neoplasms were negative for all
hormones tested. Twenty-six
tumors showed positively for more than one
hormone and usually one cell type predominated. Four patients had multiple
tumors which showed variation in the architecture and cellular composition. The
tumors were classified into three major histopathologic groups: solid, gyriform, and glandular. The correlation between the pattern of growth and the hormonal production was generally poor. However, a pure gyriform pattern was often associated with
insulin production, and glandular differentiation was commonly seen in
tumors associated with
Zollinger-Ellison syndrome. This study demonstrates the reliability of the immunocytochemical method for the specific identification of cell types in pancreatic endocrine
tumors.