Russell body duodenitis: a rare condition.

Russell bodies are accumulations of immunoglobulins within hyperstimulated plasma cells of the intestinal mucosa associated with chronic inflammation of benign progression, but may be confused with lymphoplasmacytic lymphoma, MALT lymphoma, multiple myeloma, or "signet-ring" cells, among others. There are few cases of gastric involvement, but duodenal involvement is even rarer with less than 10 published cases. Endoscopic examination with quality biopsies and anatomopathologic analysis with immunohistochemistry are essential to make an adequate differential diagnosis with other more severe processes. In any case, the treatment is that of the underlying disease.