[Carcinoid tumor of the larynx. Ultrastructural and immunofluorescence study].

Report of a 54 year-old man with a carcinoid tumor in the larynx and cervical lymph node metastasis. This left sided and dum-bell shaped tumor was spreading from the vocal cord to the piriform sinus. It was smooth, reddish and rubbery. Microscopic study showed, near by the mucosa, the tumor cells arranged in a trabecular pattern, but more disseminated and infiltrating in the deepness. Grimelius stain was positive, Masson Fontana stain negative. Electron microscopy showed neuro-secretory type granules. Immuno-histo-chemical study revealed irregularly scattered cells which were positive for ACTH, but negative for somatostatin, calcitonin and gastrin. Review of literature for this extremely rare tumor.