Neuroendocrine carcinoma of the lip (Merkel cell tumour) examined by electron microscopy and immunohistochemistry.
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.
Boysen
M
M
Department of Otolaryngology, University of Oslo, National Hospital, Norway.
Wetteland
P
P
Hovig
T
T
Brandtzaeg
P
P
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