Diverticulosis of the terminal ileum is very rare. We report a case of diverticulitis of multiple diverticula of the terminal ileum. A 67-year-old Japanese woman consulted to our hospital because of abdominal pain and melena. A blood laboratory revealed severe anemia increased CRP (11.21 mg/dl). The upper and lower gastrointestinal endoscopic examination revealed no significant changes. The colon was free from diverticulum. CT demonstrated two tumors in the small intestine. PET identified a few shadows identical to the tumors detected by CT. The clinical diagnosis was small intestinal tumors, particularly malignant lymphoma. Operation was performed, and it revealed multiple tumor-like masses in the terminal ileum. The ulcers are deep and appeared diverticula. Microscopically, the diverticula were located in the proper muscle and subserosa. The walls of the diverticula were composed of granulation tissue with heavy lymphocytic and neutrophilic infiltration. Diverticular mucosal walls were recognized in some areas. The lymphocytes were free from atypia, and no features of malignant lymphoma were recognized. The pathological diagnosis was severe diverticulitis of multiple diverticula in the terminal ileum.
Except for Meckel’s diverticulum, diverticulosis of the small intestine is very rare. If present, most of diverticulosis of the small intestine is located in the duodenum and jejunum. Diverticulosis of the ileum is extremely rare; only a few case reports are present in the English literature [1 -3 ]. We herein report a case of severe diverticulitis of multiple diverticula in the terminal ileum. Clinically, the lesions of diverticulitis were detected by CT and PET.
Microscopic features. A: Very low powerview shows that
the ulcer was diverticulum. Heavylymphocytic infiltration is seen. Ileal mucosa wasseen in the walls of the diverticulum. HE x 5. B, C:The diverticulum shows heavy lymphocytic infiltration.Ileal walls .
The lesions of the present cases are not simple ulcers but diverticula because intestinal mucosa was present in the ulcer walls. Crohn’s disease was unlikely from the histological point of view. Diverticulosis of the terminal ileum is extremely rare [1 -3 ]. The pathogenesis of the diverticulum of the terminal ileum is not known. In large bowel, it is well known that diverticula are classified into congenital and acquired. In the large bowel, congenital diverticula are free of muscular walls in the floor, while acquired ones have muscular walls. In the present case, the pathogenesis is unclear. Accumulation of much more cases are required for the pathogenesis of diverticulosis of the terminal ileum.
The diverticula of the present case showed severe diverticulitis. In general, inflammation of colon diverticula is a rare event. The pathogenesis of the severe inflammation of the diverticula of the present case was unclear. It may be possible, bacterial infection might have caused the diverticulitis. In the present case, the anemia and increased CRP may be due to the diverticulitis. The melena in the present case seems to be due to hemorrhage of the diverticula.
Interestingly, the lesions of the present case were detected by CT and PET, and clinical diagnosis was ileal tumor, particularly malignant lymphoma. This implies that PET may detect inflammatory lesions in the terminal ileum. Also, CT may detect inflammatory lesions in the terminal ileum.