DFL most commonly afflicts middle-aged adults with a male to female ration of ~1. The disease is usually asymptomatic and diagnosed as an unexpected finding when examining patients by upper GI tract endoscopy conducted for other reasons. A minority of patients present vague abdominal symptoms or, rarely, more specific and serious symptoms such as obstructive jaundice caused by tumors in the duodenum which occlude the bile duct. The endoscopic examination typically reveals one or more polyps, nodules, or confluent whitish granules located in various parts of the GI tract which in a study of 54 patients conducted in Japan were distributed as follows: first (i.e. superior or bulbus) part of the duodenum, 4 patients; second (i.e. descending) part of the duodenum, 54 patients; combined third (i.e. horizontal or inferior), and fourth (i.e. ascending) part of the duodenum, 31 patients; jejunum, 44 patients; ileum, 17 patients; cecum, 13 patients; colon and rectum, each 2 patients; and stomach and esophagus, no patients. Lesions were limited to the second part of the duodenum in only 7 patients. In some cases, the lesions may be ulcerated.
Duodenal-type follicular lymphoma
MALT lymphoma
Monomorphic epitheliotropic intestinal T cell lymphoma
Pediatric-type follicular lymphoma
Splenic marginal zone lymphoma
Nodular lymphocyte predominant Hodgkin lymphoma
Nodal marginal zone B cell lymphoma
Indolent lymphoma