<b>IMMUNOHISTOCHEMICAL DEMONSTRATION OF NEURONSPECIFIC ENOLASE IN NORMAL AND NEOPLASTIC </b><b>TISSUES </b>

Abstract

Afiinity-purified rabbit antibody against neuron-specific enolase (NSE) was prepared following the immunization of rabbits with purified human NSE. Using this antibody, the distribution of NSE was investigated immunohistochemically in normal rat and human tissues from various organs, and in many kinds of human tumors, especially of neuro-endocrine tumors. In normal rat and human tissues, NSE-like immunoreactivity was demonstrated not only in the neurons of the brain, but also in APUD cells or paraneurons of various endocrine organs. Weak immunoreactivity for NSE was also demonstrated in smooth muscle cells of various parts of the body. The diagnostic application of NSE was evaluated immunohistochemically in 251 cases of surgically resected human tumors. The results herein indicate that NSE is a useful marker for neuroendocrine or paraneuronal tumors, but NSE-like immunoreactivity was also observed in some human lung cancers which were not paraneuronal in nature. Therefore, for the diagnosis of neuroendocrine tumors, use of NSE must be combined with precise histological observation.