Interobsenrer Variability of a Papanicolaou Smear Diagnosis of Atypical Glandular Cells of Undetermined Significance

Abstract

A b s t r a c t The interobserver variability of a Papanicolaou smear diagnosis of atypical glandular cells of undetermined significance (AGUS) has not been measured. Four expert cytopathologists restrospectively reclassified 100 smears originally diagnosed as AGUSAlthough the Papanicolaou smear is one of the most effective screening tools in medicine, errors still occur. One source or error that has received a great deal of attention is diagnostic error, which is a leading cause of medical litigation.1-17 There has been considerably less study of interobserver diagnostic variability, including the relationship of variability to error and its impact on patient care. 4,18-31For Papanicolaou smear interpretation, most cytopathologists use the Bethesda System, which is composed of semiquantitative categories. 32 Interobserver diagnostic variability has been measured for only some of these categories. The diagnosis of atypical glandular cells of undetermined significance (AGUS) has been poorly characterized and has not been evaluated in terms of interobserver diagnostic variability. Follow-up studies show that a clinically significant lesion, ranging from squamous dysplasia to adenocarcinoma, is present in up to 83% of women with a diagnosis of AGUS. 33 " 41 Only 12% to 46% of these lesions are true glandular neoplasias, and up to 68% are high-grade squamous intraepithelial lesions (HSILs). 33^11 Thus, AGUS is a high-risk diagnosis. Assuming equal disease prevalence, if a laboratory has a low rate of making a diagnosis of AGUS, lesions that would be called AGUS by a second laboratory are either being classified in another clinically significant category or being missed. Such potential diagnostic discrepancies raise the possibility that some errors are simply manifestations of interobserver diagnostic variability.In this study, expert cytopathologists, including 3 cytopathology laboratory directors, retrospectively and independently reviewed 100 cases that originally were diagnosed as AGUS. Interobserver agreement, diagnostic accuracy, and

Atypical Glandular Cells: Interobserver Variability according to Clinical Management

“…Our interobserver statistical data on AGC correlates with that of others including Raab et al [25], Lee et al [26], and Simsir et al [27]; however, these prior studies utilized conventional smears rather than liquid-based preparations. Due to the timing of studies, Raab et al [25] relied on criteria from TBS from 1988, while Lee et al [26] and Simsir et al [27] referenced TBS from 2001.…”

“…Due to the timing of studies, Raab et al [25] relied on criteria from TBS from 1988, while Lee et al [26] and Simsir et al [27] referenced TBS from 2001. In the study by Raab et al [25] with 4 cytopathologist reviewers, there was complete interobserver agreement in only 15% of AGC [25]. In the study by Lee et al [26], 20.3% of AGC were reclassified by at least 1 cytopathologist reviewer [26].…”

Follow-up Study of Atypical Glandular Cells in Gynecologic Cytology Using Conventional Pap Smears and Liquid-Based Preparations

“…[14][15][16][17][18][19][20] ratio, nuclear membrane irregularities and presence of single atypical cells. 21 In this study, however, highgrade CIN is not the most common end point in follow-up assessment of AGUS/AGC cases. This may be due to the application of more stringent cytologic criteria in diagnosing glandular lesions in Queen Mary Hospital.…”

Endocervical Atypical Glandular Cells of Undetermined Significance

“…11,25,27 Hence, AGUS is still considered today "a poorly understood Bethesda System diagnostic category that needs further characterization." 22 Indeed, according to that system, the only quantitative cytologic feature identified for AGUS cases, including AIS, is a nuclear area three to five times larger than normal. 19 However, as has been the case in previous quantitative studies on AIS, 13,29 our morphometric results showed AGUS nuclear area to be only twice that of normal nuclei.…”