Diagnostic Value of Complementary Cell Block Preparation From Residual SurePath™ Pap Material for Atypical Glandular Cells

Abstract

Intoduction: Within the Bethesda Reporting System, the category of Atypical Glandular Cells (AGC) is an infrequent and diagnostically challenging interpretation, which is predictive of significant lesions in 10-40% of subsequent biopsies. Prior studies have attempted to enhance the diagnostic accuracy of AGC by creating complementary cell blocks (CB), from residual material of conventional or ThinPrep Pap specimens. These studies ranged from 22 to 71 cases, and showed resultant positivity rates of 65-75%. In our study, we sought to determine the efficacy of CB preparations from residual SurePath Pap material of our AGC cases. Materials and Methods: From February 2012 to April 2013, CBs were prepared from residual SurePath material of 57 AGC cases submitted to 2 departmental cytopathologists. During this study period, a total of 100,943 Pap tests were evaluated in our laboratory, with a resultant AGC rate of 0.03%. Results: Fifteen (27%) of our AGC CB preparations histologically demonstrated precancerous or malignant cells (Table 1, Figures 1-3). Five (9%) of the CBs revealed only scant atypical glandular cells, precluding definitive diagnosis. Two (40%) of these cases were confirmed on subsequent biopsy to be endometrial cancers. Of the remaining 37 (65%) negative CBs, 16 (43%) had surgical follow-up. Thirteen (81%) of these biopsies were positive, including 11 (85%) endometrial and 2 (15%) endocervical cancers. Thus, the overall sensitivity of our CB preparations from residual SurePath samples was 50%. Sensitivities for endocervical and endometrial cancers were 67% and 28%, respectively.