False-Positive Culture Results from Patient Tissue Specimens Due to Contamination of RPMI Medium with Cryptococcus albidus

Cryptococcus albidus, a rare opportunist, was isolated from biopsy specimens from three patients over 4 days. An investigation showed that the specimens had been contaminated by placement in RPMI medium. The importance of rapid communication between the microbiology laboratory, the infectious diseases/ infection control division, and other involved parties in the event of unusual occurrences is highlighted.