Nerve growth factor receptor in tumours of the human nervous system. Immunohistochemical analysis of receptor expression and tumour growth fraction.

The expression of nerve growth factor receptor (NGFr) was investigated by means of immunohistochemistry in 135 tumours of the human central and peripheral nervous system. The results were compared to the proliferative activity of the tumours as determined by immunostaining for the proliferation-associated antigen Ki-67. Immunoreactivity for NGFr was most consistently observed in tumours derived from the neural crest such as neurinomas, neurofibromas and ganglioneuromas. In tumours of the central nervous system, NGFr-immunostaining was particularly strong in pilocytic astrocytomas while the majority of other gliomas were either NGFr-negative or contained only a minor fraction of NGFr-positive tumour cells. Among all other investigated tumours including medulloblastomas, pituitary adenomas and meningiomas only exceptional cases demonstrated a significant number of positive tumour cells. Choroid plexus papillomas and metastatic carcinomas were always NGFr-negative. Our results indicate that NGFr-expression in tumours of the human nervous system is heterogenous with respect to tumour type and appears to be unrelated to proliferative activity.