title: [Ameloblastoma of the maxillary sinus: an electron microscopy study].
abstract: BACKGROUND
  The morphological demonstration and classification of rare tumor types occurring in the region of the head and neck may involve a number of problems.
  
  
  METHODS
  In the following the exceptional case of a plexiform ameloblastoma located in the main nasal cavity is presented. The morphological peculiarities of this locally destructive tumor are revealed by light and electron microscopy.
  
  
  RESULTS
  The light microscopic investigations show one-layered epithelial units which are interlinked in a plexiform manner and extend as far as up to the surface epithelium. The electron microscopic investigations show solid and loosened areas. The organelles are well developed, their number varied; rough endoplasmic reticulum is scarce. Glycogen incorporations occur regularly. The tumor cells are connected with a number of desmosomes. The cell surface is characterized by microvilli.
  
  
  CONCLUSIONS
  The combination of different methods of investigation is sometimes justified for diagnostic purposes. Especially electron microscopic studies may serve to demonstrate decisive structural peculiarities to classify a certain tumor type. Complete surgical removal is recommended. Postoperative radiation is generally advisable.
authors.affiliation: Hals-Nasen-Ohrenklinik, Virchow-Klinikum, Humboldt-Universität zu Berlin.
authors.forename: P A
authors.initials: PA
authors.lastname: Mir-Salim
authors.forename: V
authors.initials: V
authors.lastname: Jahnke
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000564:Ameloblastoma / Q000648:ultrastructure*; D001706:Biopsy; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008443:Maxillary Sinus / Q000648:ultrastructure; D008444:Maxillary Sinus Neoplasms / Q000648:ultrastructure*; D008854:Microscopy, Electron