Anal Cytology: Is There Any Universal Guideline for Adequacy?
G Rasty, B Bandarchi, S Hafezi, F Siadat, M Rouzbahman. University of Toronto, Toronto, ON, Canada; University of Ottawa, Ottawa, ON, Canada
Background: Anal intraepithelial neoplasia (AIN), which may be a precursor of anal carcinoma, has been identified on histology following anal biopsies. The majority of reports describe lesions occurring in homosexual and bisexual men, a group in which there is a known high prevalence of anal condylomata. Anal cytology has recently been proposed as a useful method of identifying AIN lesions. Currently there is no standard guideline for adequacy based on cellularity of the specimen and the presence of transformation zone. Our objective is to compare anal cytology with histology and HPV testing as a method of detecting AIN. We also assess the impact of cellularity of the specimen and presence or absence of glandular cells on diagnosis.
Design: We retrieved anal cytology smears of 80 HIV-seropostive patients from archives of cytology at University Health Network, University of Toronto, between January and August 2008. All samples were collected in cytolyte (Cytyc Corp.). The presence or absence of glandular cells was documented. The cellularity of samples was arbitrarily assessed as 10, 11-49 and 50 squamous cells on 10x objective. These 2 parameters were analysed against cytology interpretation, surgical diagnosis and HPV testing (Digene Corp.).
Results: The patients' age ranged from 29-71 year old (mean of 48). Four of these cases were excluded form study due to lack of concurrent biopsies and HPV testing. 61 of 76 cases had concurrent biopsies and 57 had HPV testing done on the residue of anal cytology samples. Our data revealed that the group of cases with high cellularity ( 50) shows higher diagnostic yield in cytology (61.8%), in surgical biopsies (62.3%) and HPV testing (62.7%) in comparison to lower cellularity ( 10, 11-49). Also presence of glandular cells improved the diagnostic yield in cytology (71.1%), surgical biopsies(73.8%) and HPV testing (70.1%).
Conclusions: The cellularity and presence of transformation zone elements in anal cytology are essential parameters for more accurate diagnosis. Similar guidelines used for adequacy in cervical cytology may also be applicable in interpretation of anal cytology. Larger series may be needed to establish a universal approach for interpretation.
Wednesday, March 11, 2009 9:30 AM
Poster Session V # 25, Wednesday Morning