The whole skull and spinal column were histologically studied in 55 su
ckling mice (intact and with transplantable leukemia). It was stated t
hat the lesion of the vertebral canal prevailed due to the extensive g
rowth of leukemic infiltrates in the bodies of the vertebra which had
incompletely formed cortical plate of the bone tissue. Such age-depend
ent unfinished formation of the bone marrow tissue may predispose a ra
pid development of neuroleukemia.