Neuroendocrine carcinoma of the lip (Merkel Cell tumour) examined by electron microscopy and immunohistochemistry

Abstract

AbstractA definite diagnosis of neuroendocrine carcinoma of the skin is seldom made on initial histological examination; the tumour is usually reported as a poorly differentiated or anaplastic carcinoma. By applying electron microscopy and immunohistochemistry, a correct diagnosis can be made. The ultrastructural examination shows dense-core membrane-bound granules, intermediate perinuclear filaments and desmosome-like junctions. Immunohistochemistry reveals positive staining for neuron-specific enolase and keratin, the latter in a characteristic paranuclear distribution. Confronted with an unusual clinical picture or indefinite histological diagnosis, tissue specimens should be secured for the above mentioned ancillary procedures.