Distribution of lysozyme, alpha 1-Antichymotrypsin and alpha 1-Antitrypsin in adenocarcinomas of the stomach and large intestine. An immunohistochemical study.

Lysozyme, alpha 1-Antichymotrypsin and alpha 1-Antitrypsin were demonstrated by an immunoperoxidase technique (PAP) in malignant cells of adenocarcinomas of the stomach but not of the large intestine. Lymph-node metastases showed identical immunoreactivity to that of the primary tumour. Neoplasms arising from the cardia, the body and the pyloric antrum of the stomach showed different immunostaining reactions. It seems that these differences partly reflect the distribution of lysozyme, alpha 1-Antichymotrypsin and alpha 1-Antitrypsin in the normal gastric mucosa. The usefulness of our findings in the identification of the primary tumour in cases of lymph node metastases of unknown origin, is also discussed.