title: Neuroendocrine carcinoma of the lip (Merkel cell tumour) examined by electron microscopy and immunohistochemistry.
abstract: A 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.
authors.affiliation: Department of Otolaryngology, University of Oslo, National Hospital, Norway.
authors.forename: M
authors.initials: M
authors.lastname: Boysen
authors.forename: P
authors.initials: P
authors.lastname: Wetteland
authors.forename: T
authors.initials: T
authors.lastname: Hovig
authors.forename: P
authors.initials: P
authors.lastname: Brandtzaeg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015266:Carcinoma, Merkel Cell / Q000175:diagnosis* / Q000473:pathology / Q000648:ultrastructure; D003937:Diagnosis, Differential; D005455:Fluorescent Antibody Technique; D006801:Humans; D008048:Lip Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron