Heterotopic brain tissue in the orbit
R. B. Wilkins, R. J. Hofmann, W. A. Byrd and R. L. Font
A 3-month-old female infant with Turner's syndrome was noted to have
progressive swelling of the left upper lid at the age of 1 month. A
computed tomogram demonstrated a well-circumscribed, low-density,
homogeneous orbital mass. Initially, the main clinical differential
diagnosis included dermoid cyst, hemangioma, and encephalocele. Medial
orbitotomy followed by histopathologic examination disclosed a cystic
choristomatous malformation containing brain tissue. No choroid plexuses
within the mass were demonstrated on microscopic examination. Aspiration of
fluid from the cystic mass and subsequent biochemical studies unequivocally
demonstrated that the mass was filled with cerebrospinal fluid. Despite
five surgical procedures, including two frontal craniotomies, and
specialized roentgenographic studies, no communication could be
demonstrated between the orbital mass and the central nervous system. We
postulate that the cerebrospinal fluid was produced within the orbital
mass, which represented ectopic brain tissue. Problems in diagnosis and
management of this unusual orbital malformation are discussed.
