Bilateral subpleural ectopic brain tissue in a 23-week-old fetus

Bilateral lesions were seen in the subpleural region in a 23-week-old aborted male fetus. This fetus was not macerated and showed no central nervous system abnormality on physical examination and vertebral magnetic resonance imaging (MRI). Postmortem examination revealed bilateral, paravertebral, subpleural, circumscribed, yellowish-white, fluent lesions 2.5 x 1 x 1 cm in size. These lesions were localized on the upper part of both lungs and there was no other internal malformation. Histological examination of lesions showed adult neurones and well-differentiated neural tissue with white and gray matter, choroid plexus, ependymal structures and, rarely, some peripheral neural cells in addition to immature neuroectodermal cells. These cells were more mature than those in the brain tissue.