Silver stains and immunocytochemical analysis with monoclonal serotonin antibodies for liver metastases of endocrine tumors. A study on percutaneous biopsy specimens.

With the aid of ultrasonography, representative percutaneous biopsy specimens were obtained from 20 of 21 patients (95 percent) with liver metastases of carcinoids and endocrine pancreatic tumors. The specimens were examined with silver stains and immunocytochemically after the application of monoclonal serotonin antibodies. The Grimelius argyrophil silver nitrate stain was positive in all tumor metastases, demonstrating that they were of neurohormonal endocrine type. The argentaffin reaction stained 14 of 15 metastases of small intestinal carcinoids, whereas tumors with other primary sites were unreactive. Immunocytochemical analysis with monoclonal serotonin antibodies stained all metastases of small intestinal carcinoids, and the other endocrine tumor metastases were unreactive. With immunocytochemical analysis, optimal results were obtained in Bouin-fixed tumor specimens, whereas for the argentaffin reaction, formalin was preferable. The results show that silver stains and immunocytochemical analysis with monoclonal serotonin antibodies on small percutaneous biopsy specimens of liver metastases of endocrine tumors and carcinoids are valid for the prediction of the location of the primary tumors.