Primary Mediastinal Large B-Cell Lymphoma: A Single Center Experience in Korea.

Primary mediastinal large B-cell lymphoma (PMBCL) was formally established as a distinct subtype of diffuse large B-cell lymphoma (DLBCL). Some studies indicated that patients with PMBCL have an aggressive clinical course with short median survival but more recent studies reported a relatively good response rate and survival. Therefore, controversies still exist regarding the response to therapy and prognosis of patients with PMBCL.

Between July 1993 and July 2008, a total of 26 patients with PMBCL were identified at Asan Medical Center, Seoul Korea. We retrospectively reviewed the clinic-pathologic features and clinical outcomes of them in comparison with 597 patients diagnosed with non-mediastinal DLBCL during the same period.

Out of the 26 patients, 17 (65.4%) were females and 9 (34.6%) males, while out of the 597 patients, 257 (43.0%) were females and 340 (57.0%) males (p=0.025). The median age of the PMBCL patients was 31.5 years old (range 15-78 years old), while that of the DLBCL patients was 56.0 years old (range 15-85 years old). Out of the 26 patients, 14 (53.8%) had a Ann Arbor stage III or IV disease, 7 (26.9%) had B symptoms, and by the IPI, 11 were in low, 9 in low intermediate, 2 in high-intermediate and 4 in high risk group. Out of 24 patients treated with front-line therapy CHOP or R-CHOP, 17 (70.8%) reached a CR, while 1 PR patient reached a CR after being treated with high-dose chemotherapy followed by autologous stem cell transplantation. Five refractory patients were treated with high-dose chemotherapy followed by autologous stem cell transplantation, but among them only one reached a CR and 4 died of disease progression. With a median follow-up of 41.5 months (range 1-92 months), 5-year survival rates of PMBCL and non-mediastinal DLBCL patients were 69% and 65.7%, respectively (p=0.982, Log Rank).

There was no difference between PMLBL and non-mediastinal DLBCL in terms of clinical features and outcomes.

No relevant conflicts of interest to declare.