Abstract
Although the incidence of spontaneous peptic ulceration and mucosal plaques was described in 1967, no subsequent investigation of the histology or fine structure of the duodenal lesions has been reported. Early in a scanning electron microscopic (S.E.M.) study of the duodenum of NZB mice, a lesion typified by loss of epithelial cells was observed. This paper provides a preliminary report on the nature and incidence of such lesions.