BACKGROUND The Australian Terminology for Cervical Cytology Reporting includes the category "Inconclusive‐Possible high grade epithelial abnormality." METHODS The frequency of use of this category, the types of associated cell patterns, and the yield of high grade lesions at biopsy were studied. RESULTS One hundred and two cases categorized as "Inconclusive" were reported between January and June 1995, representing 0.24% of 41,712 Papanicolaou (Pap) smears screened. The abnormal cells were reported as squamous in 74.5% of cases, endocervical in 4.9% of cases, endometrial in 3.9% of cases, and indeterminate in 16.7% of cases. The main cellular patterns included disorganized groups of hyperchromatic squamous, glandular, or indeterminate cells (64.2% of cases) and atypical metaplastic squamous cells (28.4% of cases). Cell preservation was suboptimal. In 25.3% of cases the cells were highly degenerate or air‐dried. Follow‐up included biopsy (84.3% of cases), colposcopy alone (7.8% of cases), and repeat Pap smears without any detected abnormality (3.9% of cases). No follow‐up was available in 3.9% of cases. High grade abnormalities were found in 66.3% of the biopsied cases and 55.9% of the total cases (48 cervical intraepithelial neoplasia [CIN] of Grade 2 or 3; 2 squamous cell carcinomas; 3 endocervical adenocarcinoma in situ [ACIS]; 3 adenocarcinomas of endocervical, ovarian, and endometrial origin; and 1 endometrial stromal sarcoma). In 16.2% of cases a low grade squamous lesion was present on biopsy (CIN, Grade 1 or human papillomavirus effect); and no lesion was found in 17.4% of cases. CONCLUSIONS The "Inconclusive" category was not overused, and gave a high yield of biopsy abnormalities. Accepting uncertainty in the diagnosis of some high grade lesions reduces their likelihood of being classified incorrectly as reactive changes, ignored because of poor cell preservation, or lost in the larger group of classifications such as atypical cells of undetermined significance, borderline nuclear abnormality, or non‐specific minor changes. Cancer (Cancer Cytopathol) 1998;84:208‐217. © 1998 American Cancer Society.

BACKGROUND The current study examines 1) the sensitivity of detection and 2) sampling and screening/diagnostic error in the cytologic diagnosis of adenocarcinoma in situ (AIS) of the cervix. The data were taken from public and private sector screening laboratories reporting 25,000 and 80,000 smears, respectively, each year. METHODS The study group was comprised of women with a biopsy diagnosis of AIS or AIS combined with a high‐grade squamous intraepithelial lesion (HSIL) who were accessioned by the Western Australian Cervical Cytology Registry (WACCR) between 1993–1998. Cervical smears reported by the Western Australia Centre for Pathology and Medical Research (PathCentre) or Western Diagnostic Pathology (WDP) in the 36 months before the index biopsy was obtained were retrieved. A true measure of the sensitivity of detection could not be determined because to the authors' knowledge the exact prevalence of disease is unknown at present. For the current study, sensitivity was defined as the percentage of smears reported as demonstrating a possible or definite high‐grade epithelial abnormality (HGEA), either glandular or squamous. Sampling error was defined as the percentage of smears found to have no HGEA on review. Screening/diagnostic error was defined as the percentage of smears in which HGEA was not diagnosed initially but review demonstrated possible or definite HGEA. Sensitivity also was calculated for a randomly selected control group of biopsy proven cases of Grade 3 cervical intraepithelial neoplasia (CIN 3) accessioned at the WACCR in 1999. RESULTS For biopsy findings of AIS alone, the diagnostic “sensitivity” of a single smear was 47.6% for the PathCentre and 54.3% for WDP. Nearly all the abnormalities were reported as glandular. The sampling and screening/diagnostic errors were 47.6% and 4.8%, respectively, for the PathCentre and 33.3% and 12.3%, respectively, for WDP. The results from the PathCentre were better for AIS plus HSIL than for AIS alone, but the results from WDP were similar for both groups. For the CIN 3 control cases, the “sensitivity” of a single smear was 42.5%. CONCLUSIONS To the authors' knowledge epidemiologic studies published to date have not demonstrated a benefit from screening for precursors of cervical adenocarcinoma. However, in the study laboratories as in many others, reasonable expertise in diagnosing AIS has been acquired only within the last 10–15 years, which may be too short a period in which to demonstrate a significant effect. The results of the current study provide some encouraging baseline data regarding the sensitivity of the Papanicolaou smear in detecting AIS. Further improvements in sampling and cytodiagnosis may be possible. [See editorial on pages 000–000, this issue.] Cancer (Cancer Cytopathol) 2002. © 2002 American Cancer Society.

BACKGROUND.The current study examines 1) the sensitivity of detection of invasive adenocarcinoma of the cervix in a routine cervical screening service, and 2) the frequency in smears of cytologic criteria previously found to be useful in diagnosis. METHODS. RESULTS.Thirty-six smears from 24 women were reviewed. Of those, 58.3% had been reported as a possible or definite high grade epithelial abnormality (HGEA). On review it was thought that this could be improved to 77.8%. The screening or diagnostic error was thus 19.4% and the sampling error 22.2%. The likelihood of an individual woman receiving a report of a possible or definite HGEA in the three years before biopsy was 83.3%. In retrospect this could have been improved to 91.7%. Heavy bloodstaining with abundant abnormal glandular epithelium (14 smears) and small three-dimensional or papillary clusters (16 smears) were the most frequent clues to invasion.Tumor necrosis/diathesis was present in eight smears, but easily seen in only four, while marked nuclear pleomorphism and macronucleoli were seen in three and one smears respectively. In cases with a discrepancy between the initial and the review findings, very small amounts of abnormal material (three smears), a resemblance to endometrial cells (one smear), and an unusual appearance of folded monolayered sheets (three smears) contributed to the difficulty of diagnosis.CONCLUSIONS. There were significant sampling and screening/diagnostic errors (22.2% and 19.4%, respectively). Screening and diagnostic errors could perhaps be reduced by a greater awareness of the range of cytologic changes, but these may be subtle. Heavy bloodstaining with abundant abnormal glandular material may be a useful clue to invasive, rather than in situ, adenocarcinoma, even in the absence of tumor diathesis or fully malignant nuclear criteria. Cancer (Cancer Cytopathol) 2002;96:5-13.

BACKGROUND.Little attention has been given to the reasons for failure to detect adenocarcinoma in situ (AIS) of the uterine cervix in Papanicolaou (Pap) smears. In the current study, the authors examined a series of screening or diagnostic errors in cases in which the final histologic diagnosis was either AIS or AIS combined with a high-grade squamous intraepithelial lesion (AIS ϩ HSIL). METHODS.Smears obtained in the 3 years before histologically proven AIS or AIS ϩ HSIL was diagnosed and within a specified 6-year period (1993)(1994)(1995)(1996)(1997)(1998) were reviewed and reclassified. All were conventional Pap smears. The smears studied were those with a review diagnosis of possible or definite high-grade epithelial abnormality that initially were reported by a cytotechnologist to be negative (screening error) or that were reported by a pathologist to be negative, unsatisfactory, or indicative of a low-grade epithelial abnormality (diagnostic error). A semiquantitative, blinded assessment of the frequency of cytologic criteria for the diagnosis of AIS was made for smears with erroneous diagnoses compared with a series of smears that yielded true-positive findings. CONCLUSIONS. Sampling errors were the main cause of false-negative reports in cases of AIS and AIS ϩ HSIL. The primary factors that contributed to screening or diagnostic errors in AIS were minimal, poorly preserved abnormal material and an overly conservative approach to the assessment of unusual large sheets or aggregates of glandular cells. With regard to AIS ϩ HSIL, most laboratory errors were related to the presence of crowded groups of squamous epithelial cells. There were fewer errors in the last 3 years of the study, raising the possibility of improvement over time. RESULTS.