Immunohistochemistry practices of cytopathology laboratories: a survey of participants in the College of American Pathologists Nongynecologic Cytopathology Education Program.
BACKGROUND
Immunohistochemistry (IHC) is important for cytology but poses special challenges because preanalytic conditions may differ from the conditions of IHC-positive controls.


OBJECTIVE
To broadly survey cytology laboratories to quantify preanalytic platforms for cytology IHC and identify problems with particular platforms or antigens. To discover how validation guidelines for HER2 testing have affected cytology.


METHODS
A voluntary survey of cytology IHC practices was sent to 1899 cytology laboratories participating in the College of American Pathologists Nongynecologic Cytopathology Education Program in the fall of 2009.


RESULTS
A total of 818 laboratories (43%) responded to the survey by April 2010. Three hundred fourty-five of 791 respondents (44%) performed IHC on cytology specimens. Seventeen different fixation and processing platforms prior to antibody reaction were reported. A total of 59.2% of laboratories reported differences between the platforms for cytology specimens and positive controls, but most (155 of 184; 84%) did not alter antibody dilutions or antigen retrieval for cytology IHC. When asked to name 2 antibodies for which staining conditions differed between cytology and surgical samples, there were 18 responses listing 14 antibodies. A total of 30.6% of laboratories performing IHC offered HER2 testing before publication of the 2007 College of American Pathologists/American Society of Clinical Oncologists guidelines, compared with 33.6% afterward, with increased performance of testing by reference laboratories. Three laboratories validated a nonformalin HER2 platform.


CONCLUSIONS
The platforms for cytology IHC and positive controls differ for most laboratories, yet conditions are uncommonly adjusted for cytology specimens. Except for the unsuitability of air-dried smears for HER2 testing, the survey did not reveal evidence of systematic problems with any antibody or platform.
From the Department of Pathology, University of Massachusetts Memorial Health Care, Worcester (Dr Fischer); the Department of Pathology and Genomic Medicine, The Methodist Hospital, Houston, Texas (Dr Schwartz); the Department of Pathology, AmeriPath Indiana, Indianapolis (Dr Moriarty); the Department of Pathology, Massachusetts General Hospital, Boston (Dr Wilbur); the Departments of Statistics/Biostatistics (Ms Souers) and Cytology Surveys (Ms Fatheree), College of American Pathologists, Northfield, Illinois; the Department of Anatomic Pathology, Cleveland Clinic Foundation, Cleveland, Ohio (Dr Booth); the Department of Anatomic Pathology, Mayo Clinic, Rochester, Minnesota (Dr Clayton); the Department of Cytology, Wisconsin State Laboratory of Hygiene, Madison (Dr Kurtyz); the Department of Pathology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (Dr Padmanabhan); and the Department of Pathology and Area Laboratory Services, Walter Reed Army Medical Center, Washington, District of Columbia (Dr Crothers).
Andrew H
AH
Fischer
Mary R
MR
Schwartz
Ann T
AT
Moriarty
David C
DC
Wilbur
Rhona
R
Souers
Lisa
L
Fatheree
Christine N
CN
Booth
Amy C
AC
Clayton
Daniel F I
DF
Kurtyz
Vijayalakshmi
V
Padmanabhan
Barbara A
BA
Crothers
D000230:Adenocarcinoma / Q000175:diagnosis / Q000235:genetics; D003584:Cytological Techniques / Q000379:methods / Q000592:standards*; D003625:Data Collection; D004502:Education, Medical, Continuing; D018734:Genes, erbB-2; D017408:Guidelines as Topic; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods / Q000592:standards*; D007753:Laboratories / Q000592:standards*; D010338:Pathology, Clinical / Q000379:methods / Q000592:standards*; D057089:Pathology, Molecular / Q000379:methods / Q000592:standards; D011795:Surveys and Questionnaires