Correlation of IHC with PCR
Fungal PCR was performed on FFPE and/or fresh tissues from 32 of 40 IHC-positive cases. Fungus was detected in
16 (50%) of 32 cases by PCR on one or both tissue types, and no case was PCR positive without also being IHC
positive (Table 3). For three cases, PCR was performed on both FFPE and fresh tissues; fresh tissues were negative by PCR for all three cases, whereas FFPE tissues were positive by PCR for two cases. Of 24 cases that were IHC positive but did not have PCR confirmation of Exserohilum from FFPE and/or fresh tissues, 10 (42%) had other laboratory confirmation (culture and/or PCR) of Exserohilum from other sample types (CSF or joint fluid).