Gastrointestinal Lymphoma in Southwest China: Subtype Distribution of 1,010 Cases Using the WHO (2008) Classification in a Single Institution.

UNLABELLED: The gastrointestinal tract (GIT) is the most common anatomic site of extranodal non-Hodgkin lymphoma (NHL) involvement. The classification criteria of lymphoma have changed in recent decades, and few large-sample studies regarding subtype analysis of lymphoma have been performed in this site.

AIM: Therefore, the present study was conducted to analyze the histological subtype distribution of the GIT.

METHOD: All patients in a single institution with a diagnosis of primary NHL in the GIT were enrolled between January 2007 and April 2014. The patients were categorized according to the WHO (2008) classification of tumors of hematopoietic and lymphoid tissue.

RESULT: A total of 1,010 eligible cases diagnosed as NHL were collected in this study. The male:female ratio was 1.7:1 and the median age was 55 years. The percent of patients with lymphoma involvement in the stomach was 52% (n = 522), and the remaining 48% (n = 484) had intestinal tract involvement. Histologically, diffuse large B cell lymphoma (DLBCL) was the most common subtype in all of the GIT lymphoma cases, and was also the most common subtype in cases involving the stomach (78%) and the intestinal tract (53%). The incidence of DLBCL and mucosa-associated lymphoid tissue lymphoma in the stomach was significantly higher than the incident in the intestinal tract (p < 0.01). T and NK cell lymphoma was significantly more common in the intestinal tract than in the stomach (p < 0.01). Extranodal NK/T cell lymphoma nasal type (ENKTL-N) was the most common subtype of T and NK cell lineage lymphoma in GIT and was also the second most common intestinal tract-involved lymphoma.

CONCLUSION: DLBCL was the most frequent lymphoma in the stomach and in the intestinal tract. T and NK cell lineage lymphoma had a higher occurrence in the intestinal tract than in the stomach. ENKTL-N was the most frequent subtype of lymphoma derived from NK/T cell lineage, and was the second most common lymphoma among all intestinal tract lymphomas.