Use of ThinPrep Imaging System for Primary Screening of Anal Paps: A Pilot Study.
Balamurali Varadarajalu, Maria Erroll, Andrew Schreiner, Behzad Vakil, Rana S Hoda. Weill Cornell Medical College, New York Presbyterian Hospital, New York, NY
Background: Anal Pap (AP) is used for screening of high risk population and is similar in many respects to cervico-vaginal Pap (CVP). ThinPrep Imaging System (TIS, Hologic, Boxborough, MA) detects HSIL & Carcinoma in CVP with a sensitivity of 80% vs. 74% for manually-screened ThinPrep (MSTP) (Biscotti. AJCP 2005;123:281). We sought to determine if TIS could also be utilized in primary screening of AP.
Design: AP from HIV positive patients were collected in PreservCyt® (Hologic, Boxborough, MA) via cytobrush without direct visualization and with sampling of transformation zone and processed as one Papanicolaou-stained TP. Bx of mucosal abnormalities were performed after acetic acid application via an anoscope. Two groups of AP were studied; 1) MSTP group: AP received from 01/09 to 05/09 and; 2) TIS+MSTP group: AP received from 01/10 to 08/10 (first screened on TIS and then manually screened). Results of both groups were correlated with biopsy (bx) obtained within 6 months. Technical details of TIS have been published ((Biscotti. AJCP 2005;123:281).
Results: In MSTP group 45/292 cases from 44 patients [male, 34; female,10; age range, 21-61 years (yrs); mean, 43 yrs) had subsequent bx. Twenty-two of 45 cases (49%) had HGAIN on bx. Corresponding cytologic diagnoses were: HGAIN, 5 (23%); other < HGAIN, 15; Negative, 1; Unsatisfactory, 1 (Fig.1). Upon review, 5/17 false-negative (FN) cases were cytology undercall. In TIS+MSTP group 59/263 cases from 56 patients (male, 21; female, 35; age range, 26-69 yrs; mean, 47 yrs) had subsequent bx. Twenty of 59 cases (34%) had HGAIN on bx. Corresponding cytologic diagnoses were: HGAIN, 9 (45%) and other < HGAIN, 11 (55%). Upon review, 3/11 FN cases were cytology undercall and HGAIN cells were also present in the TIS 22 fields of vision (FOV). Sensitivity of AP for detecting bx-proven HGAIN was 23% and 45% for MSTP and TIS+MSTP groups respectively (p=0.11). Corresponding specificities were 91% and 79% (p=0.20).
Conclusions: 1) Primary TIS-assisted screening of AP increases sensitivity for detection of HGAIN (p=0.11). 2) No bx-proven HGAIN cases were diagnosed as negative in TIS+MSTP group. 3) Three TIS+MSTP FN cases were interpretive errors as HGAIN cells were also present in the 22 TIS FOV.
Monday, February 28, 2011 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 56, Monday Morning