ISOLATED BONE RELAPSE DURING HEMATOLOGIC REMISSION IN CHILDHOOD ACUTELYMPHOBLASTIC-LEUKEMIA - REPORT OF A METATARSAL RELAPSE AND REVIEW OFTHE LITERATURE

An 11-year-old boy with prior bone marrow and testicular relapses of h is acute lymphoblastic leukemia (ALL) developed an isolated metatarsal bone relapse during complete hematologic remission 10 months after co mpletion of chemotherapy. Although there was no radiographic or histol ogic evidence of additional occult leukemia, the polymerase chain reac tion (PCR) technique detected a leukemic clone in both his bone marrow and metatarsal. A literature survey revealed only 10 reported cases o f isolated bone relapse occurring during complete bone marrow remissio n in childhood ALL. Most of these patients had prior bone marrow or ex tramedullary relapses. The majority experienced subsequent relapses af ter their isolated bone recurrence. We report a case of isolated bone recurrence, review all previously reported cases, and suggest that PCR elucidation of clonal disease may provide a better understanding of t hese extremely rare extramedullary events. (C) 1994 Wiley-Liss, Inc.