Immunohistochemical staining of granular cell tumour for neurone specific enolase: evidence in support of a neural origin.

Eight cases of benign granular cell tumour of tongue and skin all showed immunohistochemical staining for neurone specific enolase (NSE). Four Schwannomas, two neurofibromas and Schwann cells of nerves related to these tumours and the granular cell tumours showed no staining for NSE. NSE is a marker for neuronal type cells of the nervous system and cells of the neuroendocrine system. The results support a neural derivation of granular cell tumours. The histogenetic precursor may be an undifferentiated spindle-shaped 'reserve' cell of peripheral nerve, perhaps necessary for replacement of shed sensory organs.