[Immunohistochemical findings in intrathoracic tumors. VI. N-acetyl-beta-glucosaminidase].

N-Acetyl-beta-Glucosaminidase (NAG) activity was investigated in 50 intrathoracic tumors with a histochemical method. Altogether, 22 of 50 (= 44%) different tumors showed enzyme activity in tumor tissue. The distribution of positive findings in bronchial carcinomas showed a marked difference between epidermoid carcinomas and adenoid carcinomas. Twelve of 14 adenocarcinomas and 3 of 3 alveolar cell carcinomas contained activities of NAG in tumor tissue, whereas 16 of 17 epidermoid carcinomas and 4 of 4 large cell carcinomas showed negative findings. The fact that also non-differentiated solid adenocarcinomas, often in histological picture not to differentiate from large cell carcinomas or non-differentiated epidermoid carcinomas, exhibit NAG seems to be an useful aid in differential diagnosis between these tumor types.