Context: Non-islet-cell-tumor-induced hypoglycemia (NICTH) is caused on rare occasions by secretion of insulin from tumor cells that are reported to have a single tissue origin.
Case report: A 67-year-old male patient had cardia adenocarcinoma and concomitant lung adenocarcinoma with extensive metastases and repeated episodes of intractable hypoglycemia. Immunohistochemical staining for insulin showed that lung adenocarcinoma stained positive and gastric cardia adenocarcinoma stained weakly positive. These results indicate that tumor cells of different tissue origins co-secreted insulin.
Conclusions: This is the first report on intractable hypoglycemia due to co-secretion of insulin from two kinds of primary tumor cells in a single patient.