Frozen section diagnosis of cytomegalovirus infections.

We studied the standard frozen section as a diagnostic method for cytomegalovirus infection of the lung in bone marrow transplant recipients. Fifty-nine patients with cytomegalovirus pneumonia diagnosed by open lung biopsy were studied. The sensitivity of frozen section was compared with that of paraffin section, cytology of imprints prepared from the tissue sample, and viral culture. Fifteen percent of the cases were diagnosable at frozen section alone, and 44% by cytology alone. This confirms our previous study and indicates that frozen section unaided by more specific indentification methods provides low sensitivity even in cytomegalovirus-infected cells, which probably show the most easily identified cytopathic effects of any virus. This low sensitivity underscores the need for the additional sensitivity and specificity which may be contributed by immunolabeling techniques to rapid viral diagnosis.