[Clinicopathological Characteristics of Patients with Intestinal Diffuse Large B-Cell Lymphoma]

To investigate the clinicopathological features of intestinal diffuse large B-cell lymphoma (DLBCL).

The clinical features, pathological morphology, immunophenotype, and EBER in situ hybridization of 136 DLBCL patients diagnosed in Jinan People's Hospital Affiliated to Shandong First Medical University from January 2007 to October 2014 were analyzed retrospectively. A total of 136 DLBCL samples were obtained, the DLBCL sites were categorized as: duodenum (n=23), ileocecal region (n=63), other small intestine (n=29), rectum (n=7), and other large intestine (n=14). Survival curves for the DLBCL patients were plotted using the Kaplan-Meier method and judged by the Log-rank test.

Patients with DLBCL of the ileocecal region and other small intestine except duodenum were mainly male (P=0.042), and had a higher proportion of limited-stage tumors(P=0.015), and lower International Prognostic Index (IPI) (P=0.001). Patients with DLBCL of ileocecal region had higher incidence of lactate dehydrogenase elevation (P=0.007), and higher incidence of intestinal obstruction or perforation (P<0.001) than those with DLBCL of other regions. The 5-year overall survival and 5-year progression-free survival of patients with DLBCL in ileocecal and other small intestine sites were higher than those in other sites, but the differences were not statistically significant (P=0.135, 0.459). Fifty percent of intestinal DLBCL were germinal center B cell-like (GCB) subtypes. A low-grade B-cell lymphoma was found in 21% of 136 tumor samples. In ileocecal and other small intestinal specimens, the proportion of low-grade B-cell lymphoma was 29%, and the difference was statistically significant(P=0.025). About 16% of 136 DLBCL samples expressed follicular lymphoma while no mucosa-associated lymphoid tissue lymphoma . The Epstein-Barr virus-encoded RNA-1 (EBER1) positive rate of duodenal DLBCL was significantly higher than that of other sites (5/23, 22% vs 2/63, 3%, P=0.001).

The intestinal DLBCL is commonly observed in male, and ileocecal is the most primary site. Patients with DLBCL of the ileocecal region and small intestine except duodenum have low IPI, high proportion of limited-stage tumors, low level of lactate dehydrogenase, high incidence of intestinal obstruction or perforation, and low incidence of inert lymphoma. The EBER1 positive rate of DLBCL in duodenal is higher.