[Hyperplasia of duodenal lymph follicles accompanied by a defect of immune globulins (author's transl)].

A case report is given of a 60 year old man who complained about burning pain in the right upper abdomen and obstipation. Hyperplasia of the lymph follicles was diagnosed by duodenoscopy. An isolated defect of IgM-globulins was found. Lamblias were demonstrated in the duodenal juice as well. The hyperplasia of the lymph follicles is thought to be a manifestation of the IgM defect.