In the present study, of the 37 cases with gastrointestinal lymphoma, 25 cases (68%) were gastric lymphomas, 6 cases (16%) were small intestinal lymphomas, and 6 cases (16%) were colon lymphomas. No lymphomas were observed in the esophagus and vermiform appendix. Lewin et al. [8
], who examined 117 cases of gastrointestinal lymphomas, stated the following incidence: stomach 48/117, small intestine 37/117, ileocecal region 13/117, appendix 2/117, and colon 11/117. Taken together, the most common site of gastrointestinal lymphomas are stomach, followed in order by small intestine, colon, and appendix.
In the present study, of the 37 cases, 35 cases was B-cell lymphoma, and 2 cases were peripheral T-cell lymphomas. No NK/T cell lymphoma was recognized in the present series. Most of gastrointestinal lymphoma has been reported of B-cell type. Grody et al. [6
] stated that B cell lymphomas accounted for 84% (21/25) in gastrointestinal lymphomas. Mantle cell lymphoma, lymphoblastic lymphoma, Burkitt lymphoma, and Hodgkin disease [2
] were not observed in the present study, suggesting that these lymphomas are rare in Japan.
The age of the patients ranged from 46 to 89 years with a median of 69 years in the present study. Other reports also showed that the mean age was around 65 years [1
]. The presenting symptom was abdominal pain in 15 cases, abdominal discomfort in 6 cases, nausea and vomiting in 4 cases, diarrhea in 4 cases, constipation in 2 cases, occult blood in feces in 4 cases, and asymptomatic in 2 cases, being compatible with other studies [1
The prognosis of gastrointestinal lymphoma was not good [1
]. The prognosis of diffuse large B-cell lymphoma was poorer than MALT lymphoma [1
]. The present study did not examine the patient’s outcome.
MALT lymphoma is prevalent in the stomach [11
]. This relatively new entity (11) was in the past called reactive lymphoid hyperplasia [1
]. This condition is often associated with Helicobacter pylori
infection, as was the case of the present study. Eradication of these bacteria often leads to cure of the MALT lymphoma [1
It is well known that site of origin and histological subtypes of gastrointestinal lymphoma vary among races and geographical population. For example, it is well known that gastrointestinal lymphomas predominantly affect the stomach and intestinal lymphoma is relatively small in number (Western type), while they predominantly involves the intestine (large and small) but relatively infrequent the stomach in Middle East (Middle Eastern type) [7
]. Our hospital is a central hospital covering 300,000 persons in Shizuoka-Shimizu District of Japan. There are no particular referral centers nearby. Patients at first consult our hospital with or without consulting to private clinic. Therefore, there appears no bias of the patients in the present study. Geographical studies of primary malignant lymphoma are very rare. In Kyushu district of Japan [15
], Hong Kong [16
], Thailand [17
] and India [18
,] the sites of origin and histological subtypes of gastrointestinal lymphoma are similar to those of the present study.
For example, Nakamura et al [15
] in Kyushu University of Japan reported that the location of 455 gastrointestinal lymphomas was stomach in 342 cases (75%), intestine in 96 cases (22%) stomach and intestine in 17 cases (4%). The intestinal lymphoma involved small intestine in 72 cases, and large intestine in 24 cases [15
]. This location site is similar to that of the present study.
In their study, the histological subtypes were MALT lymphoma in 200 cases (44%), follicular lymphoma in 27 cases (6%), mantle cell lymphoma in 2 cases (0.4%), plasmacytoma in 2 cases (0.4%), diffuse large B-cell lymphoma in 175 cases (39%), Burkitt lymphoma in 6 cases (1.3%), lymphoblastic lymphoma in 4 cases (0.8%), and T-cell lymphoma in 39 cases (9%) [15
]. No Hodgkin’s disease was seen [14
]. Thus, the results of their study [15
] are similar to those of the present study. The absence of mantle cell lymphoma, plasmacytoma, Burkitt lymphoma, and lymphoblastic lymphoma in the present series is due to the rarity of these lymphomas and due to the small number of cases examined. The locations and histological subtypes of other oriental countries, such as Hong Kong [16
], Thailand [17
] and India [18
] indicated the similar results. As is well known, Hodgkin’s disease is very rare in Orient. Thus, primary gastrointestinal lymphoma of oriental countries belongs to Western type.
In Western countries, gastrointestinal lymphoma is of course of Western type; gastric lymphoma predominates over intestinal lymphoma. For example, a study from UK [19
] showed that the most common location of lymphoma is stomach (63%), followed in order by small intestine (23%) and large intestine (13%), findings similar to the present study. The histological type of lymphoma is mostly MALT lymphoma (57%) and diffuse large B-cell lymphoma (21%), and other types of lymphoma, such as Burkitt lymphoma, mantle cell lymphoma, follicular lymphoma, T-cell lymphoma are scant (23%) (19). Similar findings have been reported in Greece [20
], Denmark [9
], France [21
], and USA [11
In summary, the author reported pathologic features of 37 cases of gastrointestinal malignant lymphoma.