Psammomatous somatostatinomas of the duodenum

Abstract

The presence of psammoma bodies in carcinoid tumors of the gastrointestinal tract is a rare occurrence; it was also reported to be associated with features of somatostatin production by the tumor cells. The morphologic features of 3 such tumors arising in the [human] duodenum were studied. All tumors showed a mixed architectural pattern with prominent areas of glandular differentiation. The psammoma bodies were almost exclusively located within the glandular lumina. In each instance, the majority of tumor cells showed histochemical and immunocytochemical features of somatostatin-containing cells, and 1 tumor studied ultrastructurally showed numerous large- and small-sized intracytoplasmic secretory granules, both of which contained somatostatin. In contrast to other endocrine tumors of the duodenum having a multihormonal secretory profile, psammomatous duodenal carcinoids are associated only with somatostatin within the tumor cells. Duodenal somatostatinomas need to be included in the differential diagnosis of psammomatous tumors.