Primary Mediastinal B-cell lymphoma with sclerosis: clinical and therapeutic evaluation of 22 patients

In the last decade, there have been several reports on what is now recognized as a new clinical and pathological entity termed primarily mediastinal B-cell lymphoma (PMBCL) with sclerosis. This lymphoma presents unique clinical characteristics with an aggressive outcome and, at present, the best approach seems to be a combination of chemotherapy and radiotherapy. Between June 1989 and September 1994, twenty-two previously untreated patients with PMBCL with sclerosis were treated with a combination of third-generation chemotherapy regimen (MACOP-B or F-MACHOP) and mediastinal irradiation. All the patients presented with bulky mediastinal involvement; the radiologic clinical stage with evaluation of tumor size included computed tomography and Gallium-67-citrate SPECT. Twenty-one patients (95%) achieved a complete response and only one was resistant to treatment. Regarding 67Ga SPECT, 6 patients, including the nonresponder, showed persistent abnormal 67Ga uptake after chemotherapy; however after the mediastinal radiotherapy, all the patients except for the nonresponder were 67Ga-negative. The overall survival was 87%, with a median follow-up of 24 months from the time of diagnosis. Two of the patients who achieved complete response relapsed 7 and 10 months after completion of treatment, respectively. The relapse-free survival rate was 89% at 62 months (median 20 months). In patients presenting with bulky mediastinal PMBCL with sclerosis combined modality treatment using third-generation chemotherapy regimens and radiotherapy induces a good remission rate with greater than 80% chance of surviving disease-free, at 2 years. A longer follow-up before definitive conclusions are drawn is still warranted.