Calcified cerebral necrosis following ALL therapy

Calcified cerebral necrosis was an unusual finding at the autopsy of a 13-year-old girl who died after prolonged therapy for ALL. The patient had shown symptoms of progressive cerebral damage subsequent to a second cycle of prophylactic high-dose cytostatic therapy combined with cranial irradiation. Pathoanatomic examination revealed extensive florid recurrency of meningosis and leukemic encephalosis with scalloped calcified necroses measuring up to 5 cm, in the medullar layer of brain and cerebellum. Located predominantly near the ventricular area, encapsulated necroses showed many fibrous vessels with thickened walls and stenosed or obstructed lumina. The cerebral cortex remained largely unaffected by tissue destruction. Besides methotrexate toxicity and the enhancing effect of irradiation the vascular involvement was interpreted as a particularly important factor. Formal pathogenesis is attributed to combined chemo- and radiotherapy in parallel to leukemic infiltration of vascular walls and partial obstruction of lumina by tumor emboli. Wall damage, severe fibrosis, and consecutive nutritional defects result in the destruction of cerebral tissue. The preferential occurrence of necroses in cortex-adjacent medullar layers is explained by the relatively poor blood supply of this border zone between meningeal and intracerebral tissue, no safe conclusion can be drawn pathoanatomically with regard to the actually fatal factor, whether it is the leukemic infiltration of vascular walls, the effect of cytostatic agents, or that of irradiation. The proposed multifactorial pathogenesis of cerebral calcification may be supported by computed tomography (CT) intra vitam.