Multiple jejunal diverticulosis, from an anatomical and histological view: A case report.

BACKGROUND: Here, we report a case of jejunal diverticulosis from an anatomical and histological view. During the "Gross Anatomy course," we found multiple jejunal diverticula along a total length of 208 cm of intestine. CASE SUMMARY: After opening the intestinal tract, we counted 232 jejunal diverticulum entry points with a diameter of up to 2 cm and observed connections between the diverticula that created shortcuts between two distinct intestinal parts. Interestingly, we observed an extreme longitudinal striation on the intestinal parts hosting diverticula. Thorough vessel preparation utilizing a dissecting microscope confirmed that all investigated arteriae rectae ended in a diverticulum. Histological and immunohistochemical investigations revealed that intestinal villi of diverticula were smaller and less prominent than control tissue and that the stratum longitudinale, as well as the stratum circular, were much thinner in the diverticula compared to control tissue. Neither submucosal nor mesenteric plexus could be detected in the diverticula. However, vasoactive intestinal peptide-positive nerve fibers and villin-positive brush border could only be detected in control tissue. This indicates that jejunal diverticulosis is associated with abnormalities of the smooth muscles and a disorder of innervation. CONCLUSION: Jejunal diverticulosis originates from mesenteric vessels, featuring smooth muscle changes, absent innervation, and thinning of tissue layers.