A unique pattern of extranodal involvement in Korean adults with sporadic Burkitt lymphoma: a single center experience

Extranodal involvement is common in patients with Burkitt lymphoma (BL). We evaluated the pattern of extranodal involvement and its impact on clinical outcomes in a single center cohort of adult Korean patients with sporadic BL. We retrospectively identified 64 patients with BL in the registry of non-Hodgkin lymphoma of the Asan Medical Center between 1996 and 2009. We assessed their clinical features and distribution of extranodal sites and analyzed clinical outcomes, including complete response rate after chemotherapy, overall survival, and progression-free survival, relative to baseline characteristics and involved extranodal sites. Extranodal involvement was found in 57 patients (89 %), with 34 (53.1 %) having two or more extranodal sites. The stomach (26.6 %) was the most common site, followed by the small and large intestines (25 %), bone marrow (23.4 %), genitourinary tract (21.9 %), and bones (18.8 %). Two patients (3.1 %) showed central nervous system (CNS) involvement. Complete response rates to chemotherapy were not related to sites of extranodal involvement. Two-year overall survival rates were lower in patients with bone marrow (33.3 vs. 74.6 %, p = 0.010) and CNS (0.0 vs. 66.6 %, p = 0.048) involvement than in patients with involvement at other extranodal sites. The stomach, genitourinary tract, and bones were the most commonly involved extranodal sites in Korean BL patients, but site had no prognostic significance.