Brain heterotopia and anencephaly.

This report describes the finding of nodular collections of heterotopic brain tissue in the lungs of a stillborn anencephalic infant. Immunoperoxidase staining was performed on the nodules and on the neural tissue found at the infant's cranial defect, for neuron-specific enolase, glial-fibrillary acidic protein, carcinoembryonic antigen, and epithelial membrane antigen. The nodules were shown to consist of neurons and neuroglia. Epithelium-lined channels within the nodules were shown to have the same staining characteristics as bronchi and bronchioles in the lung, and to be different from ependyma. To our knowledge, ours is the first report of immunoperoxidase techniques being used to objectively characterize the makeup of the lesions in a case of brain heterotopia.