Guidelines for anal cytology—to make cytological diagnosis and follow up much more reliable

Abstract

Anal intraepithelial neoplasia is a difficult diagnostic and management problem, particularly when it occurs in women with synchronous or metachronous genital intraepithelial neoplasia. Diagnosis and follow up by colposcopy is too specialized for widespread use, and although anal cytology has been used before it has been thought of as too inconsistent for practical application. This study standardized collection of specimens and investigated interobserver variation. The aim of the study was to determine whether observers could reliably distinguish high grade anal intraepithelial neoplasia from other conditions. Standardized collection of anal preparations was achieved in the host centre. A meeting of experienced cytopathologists was convened to agree guidelines for anal cytology. These guidelines were sent to the panel of six observers who were subsequently circulated with 30 cytopathological preparations in random order and asked to report them all. The results were collected and processed centrally. Four individuals were in complete agreement about those preparations which were inadequate for reporting, but two others had a lower threshold for rejecting preparations as inadequate. There was agreement between the observers in over 95% of cases in distinguishing high grade intraepithelial neoplasia from other cytological conditions. Kappa values range from 0.66 to 1.00. This study demonstrates that the provision of guidelines for the interpretation of anal cytopathological preparations can result in a high degree of interobserver agreement about the clinically important distinction between high grade anal intraepithelial neoplasia and other conditions. Anal cytology is a more useful technique for diagnosis and follow up of 'at risk' individuals than has previously been suggested, and should be utilized more widely in this group of patients.

Interobserver agreement in the interpretation of anal intraepithelial neoplasia

“…26,27 Few studies have evaluated the reliability of anal specimen reporting. [17][18][19] Scholefield et al 17 circulated 30 cytology slides with material obtained from the perianal skin to 6 pathologists and reported point estimates of pairwise agreement ranging from 0.65 (moderate) to 1.00 (perfect). Carter et al 18 circulated 100 paraffin and fresh frozen histology slides to 5 pathologists.…”

“…However, previous studies on reliability for cytologic and histologic interpretations of anal intraepithelial neoplasia (AIN) specimens are limited. [17][18][19] We, therefore, assessed the interobserver agreement for interpretation of thin-layer cytology and biopsy specimens in the context of an ongoing prospective cross-sectional survey.…”

Anorectal cytology as a screening tool for anal squamous lesions

“…9,10 Fewer studies, however, have described the cytomorphologic features and diagnostic limitations associated with this new specimen type. [13][14][15] The current study evaluated the use of anorectal cytology in a high-risk population and the cytomorphologic features associated with a variety of anorectal lesions. Detection of abnormalities in ThinPrep slides is more effective than conventional preparations.…”

“…However, there are few studies addressing morphologic findings in anal cytology to support this assumption. Scholefield et al 13 reported some guidelines regarding anal cytology but included only 30 anal preparations without histologic correlation or follow-up. Sherman et al 14 described some morphologic features encountered in smears and ThinPrep (Cytyc, Boxborough, MA) preparations from anal specimens, but no histologic or anoscopic correlation was provided.…”

The value of high-resolution anoscopy in the diagnosis of anal cancer precursor lesions in hiv-positive patients

“…In this example, it is observed, with special attention, the squamocolumnar transition zone after topical application of acetic acid 3%, lesions suspected to be produced by the cytopathic effect of HPV will become whitish and underwent biopsy (26) . The histopathological result of a high resolution anoscopy (HRA) monitored biopsy is considered the goldstandard test for confirming the presence of an anal squamous intraepithelial lesion (35,43) . However, even though HRA is a tool routinely used in the diagnosis of anal lesions, there is little information in the medical literature regarding the success of this medical diagnostic technique regarding the detection of anal cancer precursor lesions.…”