Small intestinal biopsy in a patient with Crohn's disease of the duodenum. The spectrum of abnormal findings in the absence of granulomas.

The case is reported of a patient who presented with an occult anemia that was due to Crohn's disease of the duodenum. The initial evaluation revealed low serum levels of iron, folate, and carotene, and a small bowel series was abnormal but not diagnostic of Crohn's disease. Numerous small intestinal biopsy specimens were obtained from the duodenum and proximal jejunum in an unsuccessful attempt to make a diagnosis. It was shown by radiography and laparotomy 2 yr later that the patient had Crohn's disease of the proximal small intestine. This report provides a detailed analysis of the spectrum of abnormalities found by peroral mucosal biopsy in this patient. These abnormalities were patchy and included flattened mucosa, an abnormal surface epithelium which was infiltrated by large numbers of polymorphonuclear leukoyctes, increased plasma cells and polymorphonuclear leuckocytes within the lamina propria, crypt abscesses, erosions, granulation tissue, and pyloric gland metaplasia, all in the absence of granulomas. Crohn's disease should always be considered in the differential diagnosis of a proximal small bowel mucosal disease, especially when a constellation of acute inflammatory changes is present.