Plasmacytoma of Small Bowel

Plasmacytoid neoplasms of the small intestine include true plasmacytoma, diffuse large B-cell lymphoma with plasmacytoid features, and high-grade carcinoma with plasmacytoid features. Ancillary studies may be necessary to make the diagnosis. Most of these cases are diffuse large B-cell lymphomas with plasmacytoid features, although the case shown here was a true plasmacytoma.