Syndrome of inappropriate secretion of antidiuretic hormone caused by vincristine therapy: a case report of the neuropathology.

The syndrome of inappropriate secretion of antidiuretic hormone is a rare but well-recognized neurotoxic side effect of vincristine therapy. The first neuropathological report of a case is presented. A 6-month-old boy with skin leukemia developed inappropriate secretion of antidiuretic hormone caused by vincristine. Postmortem examination revealed axonal spheroids in the ansa lenticularis and the area surrounded by the substantia innominata, amygdala and supraoptic nucleus. The lesion was confined to that area and the neurosecretory neurons were intact with well preserved neurophysin. The pathological findings suggest that these fibers play a role in the development of inappropriate secretion of antidiuretic hormone caused by vincristine therapy.