CUTANEOUS INFILTRATION BY LEUKEMIC-CELLS IN ACUTE PROMYELOCYTIC LEUKEMIA OF A CHILD AFTER TREATMENT WITH ALL-TRANS-RETINOIC ACID

We describe here the first case of childhood acute promyelocytic leuke mia (APL) with cutaneous infiltration of leukemic cells following trea tment with all-trans retinoic acid (ATRA) confirmed by immunostaining and polymerase chain reaction for PML/RAR alpha. An 11-year-old girl w as diagnosed as having APL. Chromosomal analysis demonstrated the char acteristic karyotype of t(15;17). ATRA therapy was begun at a dose of 45 mg/m(2) daily. During ATRA therapy, leukocytosis and retinoic acid syndrome were observed but were resolved by dexamethasone. Two months after commencement of ATRA therapy, complete remission was achieved. D uring the course of consolidation chemotherapy, however, multiple cuta neous nodules developed in her trunk the size and number of which incr eased despite intensive chemotherapy. Histological and immunological s tudies of the cutaneous nodules showed infiltration of leukemic cells. PML/RAR alpha mRNA was detected in both the cutaneous nodules and bon e marrow by means of polymerase chain reaction. ATRA treatment for APL may be associated with an increased incidence of extramedullary disea se such as cutaneous lesions. The best available therapy for APL may b e a combination of ATRA and chemotherapy, especially when a marked leu kocytosis occurs during ATRA therapy.