Clinicopathological study of bilateral developmental cataracts diagnosed in utero.

BACKGROUND: We report a case of unusual, bilateral developmental cataracts in a fetus with a supernumerary chromosome. METHODS: A 42-year-old woman presented during her 6th pregnancy for assessment of fetal karyotype. This showed a supernumerary chromosome derived from chromosome 21. Subsequently fetal ultrasound suggested the presence of bilateral cataracts and the pregnancy was terminated at 19 weeks and 3 days' gestation. Both eyes were submitted for histopathological and electron microscopical examination. RESULTS: Histopathological examination revealed unusual bilateral developmental cataracts with abnormal bladder-type cells lining the posterior aspect of the lens vesicle, a poorly formed nuclear bow and a central mass of fibrillar material associated with macrophages lying within an area of liquefaction. Transmission electron microscopy revealed the presence of peg and socket joints in both central and posterior regions and degenerate crystallins in the posterior region. CONCLUSIONS: We described an unusual case of developmental cataract diagnosed in utero by ultrasound. The morphological appearances suggest that the defect occurred during or after formation of the secondary lens fibres. Detailed descriptions of cases such as this one may contribute to our understanding of lens development and cataract formation.