The gastrointestinal (GI) tract is the predominant site of extranodal lymphoma involvement. Primary lymphomas of the GI tract are rare, while secondary GI involvement is relatively common. Despite their rarity, primary lymphomas of the GI tract are important since their evaluation, diagnosis, management and prognosis are distinct from that of lymphoma at other sites and other cancers of the GI tract.
The definition of primary GI lymphoma has differed among authors, but typically refers to a lymphoma that predominantly involves any section of the GI tract from the oropharynx to the rectum [1,2]. While the disease typically involves a single primary site, multiple sites within the GI tract may be involved, as can local and distant lymph nodes. The vast majority are non-Hodgkin lymphomas (NHLs), although Hodgkin lymphoma has been reported [3,4].
GI lymphomas typically present with nonspecific signs and symptoms attributable to the site of involvement. This topic review will discuss the salient clinical features and diagnostic evaluation of GI lymphomas. The management of GI lymphoma is presented separately. (See "Management of gastrointestinal lymphomas".)
Distribution — The gastrointestinal (GI) tract is the predominant site of extranodal non-Hodgkin lymphomas (NHLs) . Primary NHLs of the GI tract are rare, accounting for only 1 to 4 percent of malignancies arising in the stomach, small intestine, or colon . In contrast, secondary GI involvement is relatively common, occurring in approximately 10 percent of patients with limited stage NHL at the time of diagnosis, and up to 60 percent of those dying from advanced NHL [5,7]. (See "Epidemiology, clinical features, and types of small bowel neoplasms".)
The two largest studies of GI lymphoma reported the following sites of involvement in Greek and German populations [8,9]: