[Hypothalamic syndrome as an unusual presentation of CNS relapse of acute lymphoblastic leukemia in children: report of 4 cases].

Acute lymphoblastic leukemia (ALL) is the most common malignancy in childhood, corresponding to 23 % of cancer in children younger than 15 years old. About 20 % of ALL cases will relapse, commonly in the bone marrow. Extramedullar relapses are unusual, and the two most frequent locations are CNS and testicles. ALL relapses, when diagnosed in the CNS, frequently present with clinical features of a meningeal syndrome. The hypothalamic syndrome, consisting of hyperphagia, obesity and / or behavior disturbances, corresponds to an unusual presentation of relapses in this location and should alert pediatricians to suspect it. We describe 4 ALL cases of hypothalamic syndrome at the time of CNS relapse.