Variability among observers utilizing the CellSolutions BestCyte Cell Sorter imaging system for the assessment of urinary tract cytology specimens.

INTRODUCTION: Image analysis systems are not currently commonly used for evaluating urinary cytology specimens. We evaluated whether the BestCyte Cell Sorter (CellSolutions, Greensboro, NC) imaging system can reliably identify atypical cells in urinary cytology specimens. METHODS: Fifty-three consecutive urine cytology specimens underwent 2 preparations: one slide using SurePath (SP; BD Diagnostics, Sparks, MD)™ for routine clinical evaluation, and a second slide using the CellSolutions F50 system for analysis by the BestCyte Cell Sorter (BCCS) scanning system. Eight observers reviewed atypical cells flagged by BCCS and assigned a BCCS diagnosis to each of the 53 specimens. The observers also blindly reviewed the SP preparation (when available) and assigned an SP diagnosis. The SP diagnoses given by one "expert" observer was considered as a reference diagnosis. RESULTS: There was fair-to-moderate agreement among observers for identifying any atypia and high-grade atypia (Fleiss kappa: 0.417 and 0.338, respectively) using BCCS. Review of SP preparations had slightly better agreement (Fleiss kappa: 0.558 and 0.564, respectively). Intraobserver agreement between the two methods varied greatly between individuals (Cohen's kappa range: 0.260 to 0.647). When a consensus diagnosis could be reached among the observers for cases with surgical follow-up, the consensus diagnosis was concordant in 11 of 12 instances, with one instance being a one-step discrepancy. CONCLUSIONS: Specimen review by BCCS resulted in slightly greater interobserver variability than review of routine SP preparations. This may have been due to variations in observer experience and comfort with the use of a digital imaging system, which is further suggested by the wide range of intraobserver agreement among individuals.

The Clinical Utility of the Heparin Neutralization Assay in the Diagnosis of Heparin-Induced Thrombocytopenia.

Heparin-induced thrombocytopenia (HIT) remains diagnostically challenging. Immunoassays including PF4/heparin enzyme-linked immunosorbent assay (ELISA) have high sensitivity but low specificity. Whether the heparin neutralization assay (HNA) improves the diagnostic accuracy of the PF4/heparin ELISA for HIT is uncertain. In this study, to assess its clinical utility and evaluate whether it improves the diagnostic accuracy for HIT, we implemented HNA in conjunction with PF4/heparin ELISA over a 1-year period. A total of 1194 patient samples were submitted to the laboratory for testing from December 2015 to November 2016. Heparin neutralization assay alone is a poor predictor for HIT, but it has high negative predictive value (NPV): Cases with %inhibition <70% are always negative for serotonin release assay. It improves the diagnostic positive predictive value (PPV) of ELISA without compromising sensitivity: ELISA optical density (OD) ≥1.4 alone has a sensitivity of 88% (14/16) and a PPV of 61% (14/23); with HNA %inhibition ≥70%, the sensitivity remains 88% (14/16) and PPV is 82% (14/17). 4Ts score correlates with ELISA OD and predicts HIT; the predictive accuracy of 4Ts score is further improved by HNA. Interestingly, HNA %inhibition of <70% correlates with low 4Ts scores. Based on its high NPV, HNA has the potential to facilitate more timely and accurate HIT diagnosis.

Nonuniform Distribution of High-risk Human Papillomavirus in Squamous Cell Carcinomas of the Oropharynx: Rethinking the Anatomic Boundaries of Oral and Oropharyngeal Carcinoma From an Oncologic HPV Perspective.

The oral cavity and oropharynx have historically been viewed as a single anatomic compartment of the head and neck. The practice of combining the oral cavity and oropharynx has recently been revised, largely owing to the observation that human papillomavirus (HPV)-related carcinogenesis has a strong predilection for the oropharynx but not the oral cavity. The purpose of this study was to determine whether HPV is evenly distributed across squamous cell carcinomas of the oropharynx including those sites that do not harbor tonsillar tissues such as the soft palate. A search of the medical records of the Johns Hopkins Hospital identified 32 primary squamous cell carcinomas of the soft palate (n=31) and posterior pharyngeal wall (n=1). All were evaluated with p16 immunohistochemistry and high-risk HPV in situ hybridization (ISH) (29 by RNA ISH and 3 by DNA ISH). For comparison, we also reviewed the medical records to obtain the HPV status of patients who had undergone HPV testing of primary tonsillar carcinomas over the same time interval as part of their clinical care. High-risk HPV as detected by ISH was present in just 1 (3.1%) of the 32 oropharyngeal squamous cell carcinomas, including 1 of 2 p16-positive carcinomas. The difference in HPV detection rates between tonsillar and nontonsillar sites was significant (1/32, 3.1% vs. 917/997, 92%; P<0.0001). HPV is not frequently detected in squamous cell carcinomas arising from nontonsillar regions of the oropharynx. Indeed, squamous cell carcinomas of the soft palate more closely resemble those arising in the oral cavity than those arising in areas of the oropharynx harboring tonsillar tissue. This finding not only further sharpens our understanding of site-specific targeting by HPV, but may have practical implications regarding HPV testing and even the way the oral vault is oncologically compartmentalized to partition HPV-positive from HPV-negative cancers.