Histogenesis of tumors from the nasal cavities induced by diethylnitrosamine.

Chronic subcutaneous (s.c.) or single intravenous (i.v.) injections of diethylnitrosamine (DEN) to gerbils (Meriones unguiculatus) led to the induction of carcinomas of the nasal cavities in a high incidence. These neoplasms were multifocal in origin, frequently showing mixed cellular patterns of the following cell types: large cuboidal cells, nonciliated columnar cells, ciliated columnar cells, small cells, and squamous epithelial cells. No sensory cells of the olfactory mucosa or neurofibrillar differentiations were found in these neoplasms, although several showed rosette- and pseudorosette-like formations. Dose and route of administration seemed to influence the site of origin and the patterns of cellularity of these tumors. Whereas chronic s.c. injections resulted in carcinomas of the olfactory region, being mostly composed of large cuboidal cells, single i.v. injections led to the development of carcinomas mainly originating from the respiratory-olfactory mucosal junction and composed preferentially of nonciliated and ciliated columnar cells.