Surface structures in normal, metaplastic and dysplastic nasal mucosa of nickel workers. A SEM and post SEM...

The surface fine structure of normal and abnormal nasal epithelia was examined by SEM. By the gradual increase of the luminal cell area, number and length of microvilli and the appearance of microridges, the various stages of epidermoid metaplasia (stratified cuboidal epithelium, mixed stratified cuboidal/stratified squamous and stratified squamous epithelium) could be clearly distinguished. Staging could be performed by SEM with the same degree of accuracy as histopathology. A quantitative approach for the estimation of number of microvilli and evaluation of surface areas on SEM micrographs is presented. In dysplasia, the superficial cells exhibited great variation in size and shape. The surface features of dysplastic cells consisted of densely packed knob-like structures, varying in size and shape; rount to oval, elongated or totally irregular forms were seen. When dealing with unfamiliar material a post-SEM histopathology staging by an experienced pathologist is a requisite for reliable identification of cells observed by SEM.