Dyhdalo, Kathryn

Context.— The American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) published guidelines in 2007 regarding testing accuracy, interpretation, and reporting of results for HER2 studies. A 2008 survey identified areas needing improved compliance. Objective.— To reassess laboratory response to those guidelines following a full accreditation cycle for an updated snapshot of laboratory practices regarding ASCO/CAP guidelines. Design.— In 2011, a survey was distributed with the HER2 immunohistochemistry (IHC) proficiency testing program identical to the 2008 survey. Results.— Of the 1150 surveys sent, 977 (85.0%) were returned, comparable to the original survey response in 2008 (757 of 907; 83.5%). New participants submitted 124 of 977 (12.7%) surveys. The median laboratory accession rate was 14 788 cases with 211 HER2 tests performed annually. Testing was validated with fluorescence in situ hybridization in 49.1% (443 of 902) of the laboratories; 26.3% (224 of 853) of the laboratories used another IHC assay. The median number of cases to validate fluorescence in situ hybridization (n = 40) and IHC (n = 27) was similar to those in 2008. Ninety-five percent concordance with fluorescence in situ hybridization was achieved by 76.5% (254 of 332) of laboratories for IHC − findings and 70.4% (233 of 331) for IHC + cases. Ninety-five percent concordance with another IHC assay was achieved by 71.1% (118 of 168) of the laboratories for negative findings and 69.6% (112 of 161) of the laboratories for positive cases. The proportion of laboratories interpreting HER2 IHC using ASCO/CAP guidelines (86.6% [798 of 921] in 2011; 83.8% [605 of 722] in 2008) remains similar. Conclusions.— Although fixation time improvements have been made, assay validation deficiencies still exist. The results of this survey were shared within the CAP, including the Laboratory Accreditation Program and the ASCO/CAP panel revising the HER2 guidelines published in October 2013. The Laboratory Accreditation Program checklist was changed to strengthen HER2 validation practices.

Bronchial mucoepidermoid carcinoma (MEC) is rare, comprising about 0.2% of primary lung tumors. Endobronchial ultrasound (EBUS) guided fine‐needle aspiration (FNA) cytology is an integral tool in the diagnosis and staging of malignant lung tumors. Rapid on‐site evaluation (ROSE) has been proven useful as a guide for assessing the adequacy and accuracy of the FNA samples. Therefore, comprehensive knowledge of diagnostic cytomorphologic findings of MEC is critical for ROSE.We reported a 46‐year‐old woman with 6 weeks of cough productive of yellow sputum that did not improve on antibiotics. A chest CT demonstrated a well‐circumscribed nodule in the right lower lobe bronchus that extended into the lung parenchyma. EBUS‐guided FNA was performed to obtain diagnostic materials. The ROSE of cytology specimen revealed numerous tight clusters of cells with well‐defined, but scant cytoplasm. These cells were relatively small and bland with high N/C ratio, resembling benign ductal cells. Neither cilia nor intranuclear inclusions were noted. Focal extracellular metachromatic mucinous materials were also noted. A preliminary diagnosis of “low‐grade epithelial neoplasm, favor low grade MEC” was rendered. The definitive diagnosis was confirmed by both cytology and core biopsy.EBUS‐guided FNA cytology can be a reliable method for the diagnosis of bronchial low grade MEC. The cyto‐morphology of ROSE can indicate the diagnosis of low grade MEC and direct the appropriate follow‐up triage of the specimen.Diagn. Cytopathol. 2013;41:1096–1099. © 2012 Wiley Periodicals, Inc.