The small-intestinal mucosa in patients with Crohn's disease assessed by scanning electron and light microscopy

Small-intestinal mucosal biopsy specimens obtained by a Watson capsule were assessed by light (LM) and scanning electron (SEM) microscopy in 18 patients with various sites of Crohn's disease and in 6 healthy controls. By means of LM, partial villous atrophy of the upper small-intestinal mucosa was assessed in six patients. With the use of SEM a further seven patients were shown to have mucosal abnormalities of possible clinical significance. These specimens showed a convoluted villous pattern at low-power SEM and some also enterocyte irregularity, bulging, and surface ultrastructural distortion at medium- and high-power SEM. The medium- and high-power mucosal alterations were unevenly distributed. The high prevalence of abnormalities of the upper small-intestinal mucosa in patients with Crohn's disease elsewhere in the gastrointestinal tract adds further weight to the concept of a diffuse involvement along the entire gastrointestinal tract in Crohn's disease.