Glycoprotein-hormone alpha-chain production by pancreatic endocrine tumors: a specific marker for malignancy. Immunocytochemical analysis of tumors of 155 patients.

Human chorionic gonadotropin (hCG) or its alpha- and beta-subunits have been proposed as specific quantitative markers for malignant pancreatic endocrine tumors. Since proof of malignancy of pancreatic endocrine tumors is difficult early in the course of the illness, we tested retrospectively a series of 157 pancreatic endocrine tumors of 155 patients for alpha- or beta-subunits of hCG by immunocytochemistry. Human CG-alpha-immunoreactive cells were present in 42 of 56 (75%) functioning malignant pancreatic endocrine tumors but in only one, possibly benign, glucagonoma of 67 functioning benign tumors, in only one of 17 nonfunctioning malignant and in none of 17 nonfunctioning benign tumors. No beta-hCG-immunoreactivity was localized in the tumors. Human CG-alpha appears to be a reliable quantitative and qualitative marker for malignancy in functioning pancreatic endocrine tumors.