Duodenal epithelial neoplasms complicating von Recklinghausen's disease: An immunohistochemical analysis in two patients

The authors report two patients with von Recklinghausen's disease and carcinoid tumors of the duodenum; one patient, in addition, also showed complications of an adenocarcinoma of the ampulla of Vater and multiple schwannomas, while the other patient was associated with an leiomyoblastoma of the duodenum. Histologically, both carcinoid tumors demonstrated glandular structures and psammoma bodies. Immunohistochemically, both carcinoid tumors stained diffusely positive against somatostatin. Duodenal carcinoid tumors associated with von Recklinghausen disease are characterized by originating in an ampullary lesion, by the presence of glandular structures, psammoma bodies, or both, and by being rich in somatostatin. A high prevalence of duodenal carcinoids has previously been recognized in patients with von Recklinghausen's disease, however, the association of adenocarcinoma of the small intestine and von Recklinghausen's disease is extremely rare.