[Diffuse large B-cell lymphoma with primary involvement of mediastinal lymph nodes: diagnosis and treatment]

To diagnose diffuse large B-cell lymphosarcoma (DLBCLS) with primary involvement of the mediastinal lymph nodes (LN) and to evaluate the efficiency of aggressive polychemotherapy (PCT).

The study included 15 patients (6 men and 9 women aged 18 to 70 years; median 38 years) followed up at the Hematology Research Center, Russian Academy of Medical Sciences, in 2004 to 2009. Three and 12 patients had Stages II and IE DLBCLS, respectively. B symptoms were found in 14 (93.4%) patients. Increased lactate dehydrogenase (LDH) concentrations were detectable in 14 (93.4%) patients; tumors of 10 cm or more (bulky disease) were seen in 11 (73.3%). Enlarged cervical, supraclavicular, and axillary lymph nodes were found in 9 (60%) patients; lung involvement via extension in 9 (60%), and invasion into the pericardium in 5 (33.3%) and soft tissues of the anterior thoracic wall in (13.3%). There were no signs of involvement of extranodal organs at the moment of diagnosis. All the 15 patients received PCT according to the modified NHL-BFM-90 program: 4 to 6 courses depending on the response to the therapy; 10 (66.6%) and 5 (33.3%) patients had 4 and 6 courses, respectively; for consolidating purpose, 11 (78.5%) patients were prescribed radiotherapy applied to the mediastinum in a cumulative dose of 36 Gy due to the fact that they had a residual mass.

Thirteen (86.6%) patients achieved a complete remission (CR). Primary PCT resistance was confirmed in one case. Another patient was stated to have near-complete remission. No recurrences were notified during the follow-up. The mean CR duration was 24.5 (range 2-49) months.

DLBCLS with primary LN involvement is an individual nosological entity to be differentiated from primary mediastinal large B-cell lymphosarcoma. In most cases, DLBCLS shows signs of a poor prognosis, which makes it necessary to perform aggressive PCT.