Histopathology and ultrastructure of busulfan-induced cataract.

A 49-year-old man with chronic myelogenous leukemia developed dense posterior subcapsular cataracts and punctate cortical opacities after five years of busulfan (Myleran) therapy. We found that the histopathologic appearance of busulfan-induced cataracts is similar to other forms of human and experimental cataracts, regardless of cause. Ultrastructural examination revealed cortical liquefaction with formation of Morgagnian droplets, involving primarily the region from the equator to the posterior subcapsular space. In contrast to previous findings in rats, we observed posterior migration of equatorial nuclei and bladder cell formation. Also present were socalled crystalloid rays and abundant degenerate lens fiber membranes manifested as mutli-layered, irregularly folded configurations resembling myelin figures.