[Cytological and histological studies on the fossa navicularis of the human masculine urethra (author's transl)].

These studies concern the topographic distribution of epithelia along the first 10 millimeters of the urethra after the meatus. The results are obtained by microscopical examination of 100 smears of this area and of histological sections of 5 urethral specimens removed at routine autopsy examination. The cells of 2 epithelia -- nonkeratinizing stratified squamous epithelium and stratified columnar epithelium -- are common on urethral smears; the other epithelial cells (metaplastic squamous cells, mucosal cells, anucleated cells) are less frequent or exceptional. On 91 smears of volunteers, 16 smears have no columnar cells and the other 75 smears have percentages of whole columnar cells going from 1 to 96,5% of whole epithelial cells. The number of clusters of each epithelium is very few. Microscopical examination of histological sections reveals the presence : (a) of nonkeratinizing squamous epithelium with/without leucokeratosis in 3 cases; (b) of squamous and columnar epithelia with areas of metaplastic squamous epithelium for the other 2 specimens. The significance of these results is discussed.