The pathology of the temporal bones of a child with acquired cytomegalovirus infection: studies by light microscopy, immunohistochemistry and polymerase-chain reaction.

STUDY
DESIGN: The first case of an acquired cytomegalovirus (CMV) infection of the inner ear is reported in a 3-year-old girl in remission from acute lymphocytic leukemia.
METHODS: Horizontal sections of the temporal bones were studied by light microscopy and immunohistological staining by avidin-biotin-complex-technique was performed on selected archival sections. Three sections were processed for detection of the virus genome by the polymerase chain reaction (PCR).
RESULTS: By light microscopy the epithelium of the endolymphatic sac, the utricle and the semicircular canals showed deeply stained acidophilic inclusions and the stria vascularis had a loose structure especially in the intermediate layer. The changes were limited to the non-sensory parts of the labyrinth and no CMV type cells were observed in the organ of Corti. There was a loss of inner and outer hair cells and loss of cochlear ganglion cells caused by either the virus or treatment with gentamicin. Standard immunohistochemistry failed to demonstrate staining with CMV antibodies, but PCR, demonstrated CMV-DNA in one section.
CONCLUSION: Molecular techniques may be able to detect acquired CMV infections in archival pediatric bones temporal bones. The histologic findings in the labyrinth were milder, however showed some similarity to children with congenital CMV labyrinthitis.