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.
Patient and 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.