The application of scanning electron microscopy in the clinical investigation of the human colon.

Scanning electron microscopy (SEM) of the human colon has extended the observations on gross examination and colonoscopy to ultrastructural levels. It has given a clear demonstration of submicroscopic cell surface details such as microvilli and has shown diagnostic alterations of surface topography in benign and malignant neoplasia. SEM investigation of Crohn's disease and of Clindamycin-associated colitis has shed light on the pathogenesis of the disease process. The results of the latter study demonstrated its application as an aid in the definitive establishment of the clinical diagnosis. At all times, the SEM findings have been correlated with those of light (LM) and/or transmission electron microscopy (TEM). There are advantages and disadvantages to each one of these types of microscopy. SEM serves to complement the other two and to broaden the spectrum of morphological examination.