Burkitt lymphoma: residual abdominal tumor volume after induction therapy correlates with outcome.

Staging investigations in the Malawi 2003 BL protocol included abdominal ultrasonography. This sometimes demonstrated tumor that was not palpable. Patients with no palpable tumor following induction with three courses of cyclophosphamide were considered to be in remission, although residual intraabdominal tumor was documented in some by chance. We repeated ultrasonography on day 29 on 22 new patients with non-palpable abdominal BL following induction. The relapse rate after 1 year correlated with the largest residual tumor volume, and was 17% for tumors 0-35 ml, and 75% for tumors > or = 35 ml in volume. Risk patients were thus identified.