A study with the electron microscope of the jejunal epithelium in primary malabsorptive disease.

Jejunal biopsy specimens were obtained by means of the Crosby capsule from a normal person and from seven patients. Of these, three with primary malabsorptive disease (idiopathic steatorrhoea) had an abnormal mucosal pattern under the light microscope, and the microvilli under the electron microscope were stunted, broadened, and sparse. Two with primary malabsorptive disease had normal light microscopic appearances, and the microvilli appeared normal, while two who had appearances typical of primary malabsorptive disease under the light microscope had malignant disease of the small intestine. Of the patients with malignant disease, one had normal microvilli under the electron microscope and the other demonstrated microvilli similar to those found in primary malabsorptive disease. The former patient may have had primary malabsorptive disease in addition to the malignant change but this is uncertain, and there is no reason to believe that this was the case in the latter patient. The changes seen under the light microscope are usually of great value as an aid to diagnosis in primary malabsorptive disease but this is not always the case, and the same applies to electron microscope changes.