The significance of a residual mediastinal mass following treatment for aggressive non-Hodgkin's lymphomas.

The chest radiographs of 252 patients with aggressive non-Hodgkin's lymphoma, prospectively treated according to one of three protocols of combination chemotherapy, were reviewed to determine the incidence and prognostic significance of mediastinal abnormalities following treatment. Residual mediastinal masses were defined as any abnormality, greater than 2 cm in diameter, that had initially responded to chemotherapy and then remained stable in size for at least three months after its maximal response, together with the disappearance of all other clinical and biological signs of active lymphoma. At the end of treatment, 21 (8%) patients had some residual mediastinal abnormality. The predominant histological pattern was the diffuse large cell subtype (p less than 0.001). Disease free survival and overall survival for these patients were similar to those observed among patients in complete remission without a persisting radiological mass after treatment. We conclude that mediastinal residual masses after completion of treatment for aggressive lymphoma are frequent and do not indicate a poorer prognosis. Such patients can be observed clinically without any need for additional chemotherapy or radiotherapy.