title: Using immunohistochemistry to assess the accuracy of histomorphologic diagnosis of aspergillosis and mucormycosis.
abstract: BACKGROUND
  Data on the accuracy of conventional histomorphologic diagnosis are limited, especially in mucormycosis. We therefore investigated the accuracy of histomorphologic diagnosis of mucormycosis and aspergillosis, using immunohistochemistry (IHC) tests for mucormycosis and aspergillosis.
  
  
  METHODS
  Patients enrolled met the modified criteria for proven and probable mucormycosis (during a 22-year period) or invasive aspergillosis (during a 6-year period) and had formalin-fixed, paraffin-embedded tissues available. We first tested the diagnostic performance of IHC for mucormycosis and aspergillosis in proven cases. Then we determined the accuracy of histomorphologic diagnosis of probable cases, using the IHC tests.
  
  
  RESULTS
  In 7 proven cases of mucormycosis, the sensitivity and specificity of mucormycosis IHC were 100% (95% confidence interval, 65%-100%) and 100% (68%-100%), respectively. In 8 proven cases of aspergillosis, and the sensitivity and specificity of aspergillosis IHC staining were 87% (53%-98%) and 100% (65%-100%), respectively. Of 23 probable mucormycosis cases, 20 (87%) were positive with mucormycosis IHC, 2 (9%) were positive with aspergillosis IHC (including 1 positive for both), and 2 were negative with both. Of 16 probable aspergillosis cases, 10 (63%) were positive with aspergillosis IHC, 4 (25%) were positive with mucormycosis IHC, and 2 (13%) were negative with both tests.
  
  
  CONCLUSIONS
  Aspergillosis and mucormycosis seem not to be correctly diagnosed morphologically, because some of the probable cases showed either test with both antibodies or failure to stain with the homologous antibody. In the absence of fungal culture results, the IHC tests seem helpful in differentiating between aspergillosis and mucormycosis.
authors.affiliation: Department of Infectious Diseases.
authors.forename: Jiwon
authors.initials: J
authors.lastname: Jung
authors.affiliation: Department of Pathology.
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Park
authors.affiliation: Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Heungsup
authors.initials: H
authors.lastname: Sung
authors.affiliation: Department of Pathology.
authors.forename: Joon Seon
authors.initials: JS
authors.lastname: Song
authors.affiliation: Department of Infectious Diseases.
authors.forename: Sang-Oh
authors.initials: SO
authors.lastname: Lee
authors.affiliation: Department of Infectious Diseases.
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Infectious Diseases.
authors.forename: Yang Soo
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Infectious Diseases.
authors.forename: Jun Hee
authors.initials: JH
authors.lastname: Woo
authors.affiliation: Department of Infectious Diseases.
authors.forename: Sung-Han
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000328:Adult; D001230:Aspergillus / Q000648:ultrastructure; D000068598:Data Accuracy; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D055744:Invasive Pulmonary Aspergillosis / Q000175:diagnosis* / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D009091:Mucormycosis / Q000175:diagnosis* / Q000382:microbiology; D009172:Mycology / Q000379:methods; D016133:Polymerase Chain Reaction; D012233:Rhizopus / Q000648:ultrastructure; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: aspergillosis; histomorphology; immunohistochemistry; mucormycosis