Prospective screening was carried out in 12 members of three families with
multiple endocrine adenopathies, type I (MEA,I) and in 14 patients with no
multiple endocrine adenopathies with and without other endorcinopathies. Elevated basal and responsive (after a meal) plasma concentrations of a relatively new candidate-
hormone, human
pancreatic polypeptide (
hPP), were associated with pancreatic
apudoma tumors in three asymptomatic patients with
multiple endocrine adenopathies, type I. Two of these patients had excision of the
tumors that resulted in normal plasma
hPP concentrations postoperatively. Both
tumors contained
hPP predominantly by immunocytochemistry; one, a pure
pancreatic polypeptide apudoma, was studied extensively demonstrating also by radioimmunoassay a high content of
hPP and negligible amounts of
insulin,
glucagon,
somatostatin,
vasoactive intestinal polypeptide and
gastrin. In this patient plasma concentrations of other
polypeptides including
insulin,
glucagon,
somatostatin,
vasoactive intestinal polypeptide,
gastrin,
parathyrin,
thyrocalcitonin,
prolactin,
corticotropin,
growth hormone, thyrtropin and
amine,
serotonin, were within normal limits. The other patient, after excision of an
hPP-detected pancreatic mixed
hPP-
gastrinoma, also became eugastrinemic postoperatively. Normal basal plasma
hPP concentrations, but with exaggerated
hPP responses to a meal in 11 patients, were associated with various combinations of islet cell
hyperplasia,
antral G cell
hyperplasia with moderate hypergastrinemia and parathyroid
hyperplasia. The patients with
multiple endocrine adenopathies who have demonstrated this type of increased
hPP response to a meal have not been operated on but are at risk for islet
hyperplasia. Four of the 12 patients with
multiple endocrine adenopathies, type I, with both normal basal and normally responsive
hPP concentrations have no evidence as yet of pancreatic involvement.