Immunohistochemical and electron microscopic observations of nevic corpuscle

Nevic corpuscle in the pigmented nevus was studied under light microscopy in comparison with Meissner corpuscle of the human sole skin in order to determine its ontogenesis. No nerve fibers within nevic corpuscle but coiled fibers in Meissner corpuscle could be demonstrated by Bodian stain. Presence of S-100 protein in the pigmented nevus and Meissner corpuscle was observed under light microscopy utilizing peroxidase-antiperoxidase immunohistochemical staining. S-100 protein was more evident in nevic corpuscles than in Types A and B intradermal nevus cells. Meissner corpuscle showed moderate stainability for S-100 protein. Ultrastructural study revealed that the nevic corpuscle was composed of the laminated cells with flattened cytoplasmic processes but lacked peripheral nerve endings such as axons, characteristically shown in Meissner corpuscle. No melanogenic activity of nevic corpuscle was observed. These morphological and histochemical findings of nevic corpuscle did not enable us to give definite conclusion on its ontogenesis.