Villous tumors of the duodenum: a clinicopathologic study.

Eight villous tumors of the duodenum were found and studied in a review of surgical and autopsy material collected over 30 years. Although the number of cases is small, it is nevertheless one of the largest single series on this lesion that has been reported. The purposes of the study were (1) to describe the histopathology of the lesions and (2) to test the diagnostic criteria of malignancy previously proposed in the literature. Of the large number of criteria studied, none, alone or in combination, proved reliable indicators of malignancy; even in this small series exceptions could be found. Of all the criteria tested, however, secondary gland formation was found to be the most reliable. The value of endoscopic biopsies in establishing the preoperative diagnosis of malignancy in this lesion seems to be analogous to that in similar colonic lesions. Prognostic and therapeutic criteria are discussed. In addition, the pertinent literature is reviewed.