Acute renal failure due to leukemic cell infiltration followed by relapse at multiple extramedullary sites in a child with acute lymphoblastic leukemia

Acute renal failure due to leukemic infiltration into the kidney is rare in childhood acute lymphoblastic leukemia (ALL). We report here a five year-old boy with ALL who presented acute renal failure caused by leukemic infiltration at onset. Treatment with predonisolone and hemodialysis was effective. However, he showed persistent or repeated relapses at extramedullary sites, such as central nervous system, testis, and pancreas, suggesting that leukemic cells of this patient may have had a high affinity to extramedullary organs. On the basis of previous reports and the experience of this patient, intensive treatment may be needed in ALL children with renal involvement.