Cystic pancreatic glucagonoma in contact with insulinoma found in a hypoglycemic patient.

Cystic glucagonoma in contact with insulinoma was found in the pancreas of a 28-year-old female patient with characteristic hypoglycemic syndrome. Among six tumors in total detected in the tail of the resected pancreas, the largest solid tumor (2.5 cm in diameter) consisted mostly of insulin-containing cells with conspicuous amyloid deposition. Contiguous to this tumor, the second largest nodule, measuring 1.8 cm in diameter, showed cystic changes and consisted of glucagon-containing cells. High concentration of immunoreactive glucagon was demonstrated in the cystic fluid. In addition to the cystic changes of endocrine pancreatic tumors, simultaneous occurrence of glucagonoma in contact with insulinoma appears to be extremely rare and repeated episodes of hypoglycemia may contribute to its pathogenesis.