Adenocarcinoma in situ of the uterine cervix

False Negative Results in Cervical Cancer Screening-Risks, Reasons and Implications for Clinical Practice and Public Health

False negative (FN) results in cervical cancer (CC) screening pose serious risks to women. We present a comprehensive literature review on the risks and reasons of obtaining the FN results of primary CC screening tests and triage methods and discuss their clinical and public health impact and implications. Misinterpretation or true lack of abnormalities on a slide are the reasons of FN results in cytology and p16/Ki-67 dual-staining. For high-risk human papillomavirus (HPV) molecular tests, those include: truly non-HPV-associated tumors, lesions driven by low-risk HPV types, and clearance of HPV genetic material before sampling. Imprecise disease threshold definition lead to FN results in visual inspection with acetic acid. Lesions with a discrete colposcopic appearance are a source of FN in colposcopic procedures. For FAM19A4 and hsa-miR124-2 genes methylation, those may originate from borderline methylation levels. Histological misinterpretation, sampling, and laboratory errors also play a role in all types of CC screening, as well as reproducibility issue, especially in methods based on human-eye evaluation. Primary HPV-based screening combined with high quality-assured immunocytochemical and molecular triage methods seem to be an optimal approach. Colposcopy with histological evaluation remains the gold standard for diagnosis but requires quality protocols and assurance measures.

False-negative Papanicolaou tests in women with biopsy-proven invasive endocervical adenocarcinoma/adenocarcinoma in situ: a retrospective analysis with assessment of interobserver agreement

INTRODUCTION

The objectives of our study were to identify factors contributing to false-negative Papanicolaou (Pap) tests in patients with endocervical adenocarcinoma (EA) or adenocarcinoma in situ (AIS), and to analyze the impact of educational instruction on interobserver agreement in these cases.

MATERIALS AND METHODS

False-negative Pap tests from patients with EA/AIS were reviewed by a consensus group and by 12 individual reviewers in 2 rounds, with an educational session on glandular neoplasia in Pap tests conducted between the 2 rounds.

RESULTS

Of 79 Pap tests from patients with EA/AIS, 57 (72.2%) were diagnosed as abnormal and 22 (27.8%) as negative. Of the 22 false-negative cases, 10 remained negative on consensus review, with false-negative diagnoses attributed to sampling variance. The other 12 cases were upgraded to epithelial abnormalities (including 8 to glandular lesions). The false-negative diagnoses were attributed to screening variance in 2 cases and interpretive variance in 10 cases. On individual review, abnormal cells were misinterpreted as reactive glandular cells or endometrial cells in 7 of 8 and 5 of 8 cases upgraded to glandular abnormalities, respectively. With education, the proportion of individual reviewers demonstrating at least moderate agreement with the consensus diagnosis (Cohen's kappa >0.4) increased from 33% (4 of 12) to 75% (9 of 12).

CONCLUSIONS

Sampling and interpretive variance each accounted for nearly one-half of the false-negative Pap tests, with underclassification as reactive glandular or endometrial cells the main source of the interpretive variances. Educational instruction significantly decreased the interpretive variance and interobserver variability in the diagnosis of glandular abnormalities.

Cervical adenocarcinoma in situ: Human papillomavirus types and incidence trends in five states, 2008-2015

Primary prevention through the use of human papillomavirus (HPV) vaccination is expected to impact both cervical intraepithelial neoplasia (CIN) and adenocarcinoma in situ (AIS). While CIN is well described, less is known about the epidemiology of AIS, a rare cervical precancer. We identified AIS and CIN grade 3 (CIN3) cases through population-based surveillance, and analyzed data on HPV types and incidence trends overall, and among women screened for cervical cancer. From 2008 to 2015, 470 AIS and 6,587 CIN3 cases were identified. The median age of women with AIS was older than those with CIN3 (35 vs. 31 years; p < 0.01). HPV16 was the most frequently detected type in both AIS and CIN3 (57% in AIS; 58% in CIN3), whereas HPV18 was the second most common type in AIS and less common in CIN3 (38% vs. 5%; p < 0.01). AIS lesions were more likely than CIN3 lesions to be positive for high-risk types targeted by the bivalent and quadrivalent vaccines (HPV16/18, 92% vs. 63%; p < 0.01), and 9-valent vaccine (HPV16/18/31/33/45/52/58, 95% vs. 87%; p < 0.01). AIS incidence rates decreased significantly in the 21-24 year age group (annual percent change [APC] overall: -22.1%, 95% CI: -33.9 to -8.2; APC among screened: -16.1%, 95% CI: -28.8 to -1.2), but did not decrease significantly in any older age group. This report on the largest number of genotyped AIS cases to date suggests an important opportunity for vaccine prevention of AIS, and is the first to document a decline in AIS incidence rates among young women during the vaccine era.

Challenges in the Pap diagnosis of endocervical adenocarcinoma in situ

INTRODUCTION

Recognition of adenocarcinoma in situ (AIS) in cervical cytology is challenging.

MATERIALS AND METHODS

We calculated the sensitivity and accuracy of Papanicolaou (Pap) tests obtained within 1 year of a histologic diagnosis of AIS from 2007 to 2016. We also correlated it with the coexistence of squamous lesions, calculated the interobserver agreement, and compared these measures with those of endocervical adenocarcinoma (ECCA). We correlated AIS detection with high-risk human papillomavirus (hrHPV) status.

RESULTS

Of 72 patients with histologic AIS and 48 patients with ECCA, 92% and 87.5%, respectively, had abnormal Pap test results. A glandular abnormality was detected in 44.4% of the AIS and 77.1% of the ECCA cases. Complete cytohistologic concordance was reached in 8.3% of AIS and 22.9% of ECCA cases. In addition, 27.8% of AIS and 6.3% of ECCA cases were diagnosed on Pap as a high-risk squamous abnormality. Concurrent squamous lesions were present in 79.2% of patients with AIS and 29.2% of patients with ECCA. The Paps from the AIS and ECCA cases were diagnosed as pure squamous abnormalities in 47.2% and 10.4% of cases, respectively. In the AIS cases, interobserver agreement was substantial for detection of any high-risk cytologic abnormality (kappa = 0.67) and fair for detection of any glandular abnormality (kappa = 0.34). Among the 26 patients with AIS tested for hrHPV, 92% had positive results and 8% had negative results.

CONCLUSIONS

The cytologic sensitivity for the detection of AIS remains low. It is directly related to the coexistence of squamous lesions. Cytology and hrHPV as stand-alone screening tests fail in the early detection of a small proportion of glandular lesions, although combined testing will improve their detection rates.

Cytologic patterns of cervical adenocarcinomas with emphasis on factors associated with underdiagnosis

BACKGROUND

New cervical cancers continue to be diagnosed despite the success of Papanicolaou (Pap) tests. In an effort to identify pitfalls that limit the diagnosis of adenocarcinoma, the authors reviewed the cytologic characteristics of endocervical adenocarcinomas in their patient population.

METHODS

Liquid-based cytology slides from 45 women who had concurrent, histologically confirmed cervical adenocarcinomas were reviewed retrospectively and semiquantitatively for 25 key cytologic traits. The original sign-out diagnosis, available clinical findings, and high-risk human papillomavirus (HR HPV) results also were noted.

RESULTS

Abundant tumor cellularity, nuclear size from 3 to 6 times normal, abundant 3-dimensional tumor cell groups, round cell shape, and cytoplasmic neutrophils characterized the 23 cases that were identified correctly as adenocarcinomas. Key reasons for undercalls included low tumor cellularity and low-grade columnar morphology; these also tended to correlate with low-grade or unusual adenocarcinoma variants on histology. Overall, 73% of adenocarcinomas had a concurrent positive HR HPV test.

CONCLUSIONS

Most endocervical adenocarcinomas can be diagnosed accurately in cases with classical features, but some cases continue to be problematic when evaluated based on cytologic features alone. Reflex HPV testing may help increase Pap test sensitivity for challenging cases that have atypical glandular cells of undetermined significance. Occasional cases with negative HR HPV test results remain of concern.

Detection of in situ and invasive endocervical adenocarcinoma on ThinPrep Pap Test: Morphologic analysis of false negative cases

Background:

The goal of this study was to calculate the sensitivity and false negative (FN) rate of ThinPrep Pap Test (TPPT) and carefully analyze missed cases for educational purposes.

Materials and Methods:

Patients with histologically proven adenocarcinoma in-situ (AIS) or invasive endocervical adenocarcinoma (EAC) over a 17-year-period (1998-2015) were identified. The TPPT immediately preceding the histological diagnosis of AIS/ECA was designated as index Pap (IP). Paps up to 122 months before histologic diagnosis of AIS/ECA were considered for this study. All available negative and unsatisfactory TPPT were re-reviewed.

Results:

There were 78 patients with histologically-proven AIS (56) or ECA (22) with 184 TPPTs, and 95 of these TPPTs were abnormal. Of the abnormal cases, 55.7% TPPTs were diagnosed as endocervical cell abnormality (atypical endocervical cells/AIS/ECA). Notably, 44.2% of abnormal TPPTs were diagnosed as squamous cell abnormality (atypical squamous cells of undetermined significance/low-grade squamous intraepithelial lesion/high grade squamous intraepithelial lesion). Including the diagnoses of squamous cell abnormality, the sensitivity of index TPPT for histologically-confirmed AIS/ECA was 88%. Eighty-eight of 184 TPPT, including 10 IP, were negative = 87, or unsatisfactory = 1. Forty-two of these slides were available for re-review. Upon review, 21 TPPT (50%) were confirmed negative and 21 TPPT (50%) were reclassified as abnormal = 20, or unsatisfactory = 1. Of the FN cases, the main difficulty in correct diagnosis was the presence of few diagnostic cell clusters which had less feathering, and consisted of smaller, rounder cells in small and tighter clusters, with nuclear overlap. In particular, nuclear overlap in three-dimensional groups precluded the accurate diagnosis. Rare FN cases showed squamous cell abnormality on re-review, and rare cases showed obscuring blood or inflammation.

Conclusion:

A significant proportion of AIS/EAC is discovered after Pap showing squamous cell abnormality. FN cases were most commonly related to nuclear overlap in tight three-dimensional clusters.

Clinical parameters associated with absence of endocervical/transformation zone component in conventional cervical Papanicolaou smears

OBJECTIVE

To study clinical factors predicting the absence of endocervical/transformation zone (EC/TZ) components of conventional cervical Papanicolaou (Pap) smears.

MATERIALS AND METHODS

The medical charts of patients who received Pap smears between March 2006 and August 2006 in the hospital were reviewed. The results of their Pap smears were retrieved while their demographic and clinical information were obtained from the medical charts. After excluding 378 cases with incomplete demographic data and 1397 cases with a history of pelvic irradiation, pelvic malignancy, and hysterectomy, 5662 cases were enrolled for data analysis. The relationship between clinical parameters and the absence of EC/TZ component was analyzed by Pearson Chi-square tests with Yates continuity correction and binary logistic regression tests.

RESULTS

The incidence of satisfactory but absence of EC/TZ component was 8.7% (491/5662). Pregnancy increased the absence of EC/TZ component [odds ratio (OR}: 2.84, 95% confidence interval (CI): 2.14-3.77, p<0.0001]. Postpartum status and endocervical polyps decreased incidence (OR: 0.61, 95% CI: 0.38-0.98, p = 0.043 and OR: 0.33, 95% CI: 0.25-0.44, p<0.0001, respectively).

CONCLUSIONS

Pregnancy is the only clinical factor associated with increased incidence of absence of EC/TZ cells. For these pregnant women undergoing a Pap smear, a more effective strategy may be needed to get a satisfactory smear with adequate EC/TZ components.

Practical issues related to uterine pathology: in situ and invasive cervical glandular lesions and their benign mimics: emphasis on cytology-histology correlation and interpretive pitfalls

In situ and invasive neoplastic glandular lesions of the uterine have cytologic correlates that must be distinguished from a variety of benign and reactive conditions. Careful study of the cytologic features allows discrimination in the majority of cases; however, the designation of 'atypical glandular cells' is reserved for equivocal cases that cannot be readily resolved. In this article, the cytologic features of endocervical adenocarcinoma in situ and invasive endocervical adenocarcinoma will be presented, highlighting their correlation to the well-known histologic features. Variants of the usual type of endocervical neoplasms that have important clinical and differential diagnostic features, including mucinous adenocarcinoma and clear-cell carcinoma, will be discussed. There are a number of common cytologic mimics of endocervical neoplasms, including tubal metaplasia, directly sampled (abraded) endometrium, and high-grade squamous intraepithelial lesion involving endocervical glands. The cytologic features of these entities and their differentiation from endocervical neoplasia will be explored. Finally, the role of ancillary studies such as human papillomavirus testing in the management of glandular lesions of the cervix will be integrated into the discussion.

Cytological variations and typical diagnostic features of endocervical adenocarcinoma in situ: A retrospective study of 74 cases

Background:

The sensitivity of Papanicolaou smears for detecting endocervical adenocarcinoma in situ (AIS) is very low. A comprehensive cytological analysis of endocervical AIS is necessary to increase diagnostic accuracy.

Methods:

The subjects were 74 patients with pathologically-diagnosed AIS. A total of 140 Papanicolaou smears were reviewed to calculate the sensitivity of the Papanicolaou smears for detecting AIS and the incidence of sampling/screening/diagnostic errors. The cytological review was performed by 6 cytotechnologists, and the final cytological diagnosis was obtained at the consensus meeting. We classified the cases into three differentiation types; typical type (well-differentiated AIS), polymorphic type (poorly differentiated AIS), and mixed typical and polymorphic type. Three cytological subtypes (endocervical, endometrioid and intestinal subtypes) of AIS were also analyzed.

Results:

The sensitivity of the original Papanicolaou smears for the detection of AIS was 44.6%, while that for the detection of AIS and adenocarcinoma was 63.5%. The diagnostic accuracy of AIS increased to 78.5% in the final diagnosis. The common characteristic features were microbiopsies/hyperchromatic crowded groups (HCG) (82.0%) and mitotic figures (72.2%). The appearance of single cells (2.8%) was rare, and all the cervical cytology smears showed no evidence of necrotic tumor diathesis. The most common AIS was the typical type (41 cases, 67.2%) among all cytologically-diagnosed AIS or adenocarcinoma cases (61 cases). Although mixed typical and polymorphic AIS existed in 17 cases (27.9%), pure polymorphic AIS was very rare (3 cases, 4.9%). The endocervical subtype was the most predominant subtype (67.2%), followed by a few mixed subtypes. The important diagnostic keys for AIS cytology are as follows: (1) The appearance of microbiopsies/HCG (single-cell pattern is rare), (2) mitotic figures in the microbiopsies/HCG, (3) a lack of necrotic tumor diathesis in cases with polymorphic AIS, and (4) recognition of typical cytological subtypes.

Conclusions:

The relatively low diagnostic accuracy AIS was caused by the underestimation of microbiopsies/HCG and the overestimation of polymorphic components. The typical cytological features of AIS are the presence of microbiopsies/HCG with mitotic figures in the absence of necrotic tumor diathesis in specimens containing endocervical samples. The recognition of infrequent AIS subtypes (endometrioid and intestinal subtypes) is also important.

Cytological screening of endocervical adenocarcinoma

Invasive endocervical adenocarcinoma represents on average 15% of cervical carcinomas and it is associated with the human papillomavirus infection high risk types 16 and 18 in most cases. Its detection has some special features compared to squamous cell carcinoma; glandular precancerous lesions are less known and only adenocarcinoma in situ is diagnosed by consensus among pathologists; adenocarcinoma in situ develops in the squamocolumnar junction by reserve cells but it is hard to be located by colposcopy in the endocervical canal or in the deep glandular recess. Sampling of endocervical cells requires brushes rather than an Ayre spatula. Cytological diagnosis of glandular cells abnormalities is based on the Bethesda System 2001 terminology which redefined endocervical cells abnormalities and also introduced the entity of adenocarcinoma in situ. This entity is characterized by specific morphological features, such as the radial arrangement of nuclei in the periphery, like "at the end of the feathers of a bird's wing"(feathering of cells), images of nuclei palissading or rosette without tumoral diathesis. Glandular cells abnormalities are rare and represent less than 0.1% of all smears and less than 5% of abnormal smears. By improving the collection and the interpretation of abnormal endocervical cells, cytological screening should allow the diagnosis of in situ adenocarcinoma and detection of invasive adenocarcinoma at a very early stage. This will lead to a decrease in mortality from endocervical adenocarcinoma, especially in young women.

Histologic follow-up results in 662 patients with Pap test findings of atypical glandular cells: results from a large academic womens hospital laboratory employing sensitive screening methods

OBJECTIVE

Atypical glandular cell (AGC) Pap interpretations and screening for glandular neoplasias remain major challenges. We document the largest reported AGC histopathologic follow-up experience and include verification bias-adjusted data on laboratory screening sensitivity.

METHODS

AGC Pap tests of endocervical origin (AGC-EC), endometrial origin (AGC-EM), and not otherwise specified (AGC-NOS) were documented at a center serving an older low risk population. 98% of Pap tests were liquid-based cytology (LBC) specimens screened using computer-assisted screening. Follow-up diagnoses were correlated with cytology and stratified into age groups. Screening sensitivity was assessed by examining Pap results during 1 year preceding neoplastic diagnoses. Verification bias was adjusted with findings in over 2000 patients with hysterectomies.

RESULTS

Of 247,131 Pap tests, 1021 (0.41%) reported AGC results and 662 cases had tissue follow-up. Precancerous or malignant neoplastic histologic outcomes were documented in 101 patients (15.3%), including 8.3% cervical, 6.3% endometrial, and 0.6% ovarian. AGC results were most often associated with neoplastic cervical outcomes in women younger than 40 and with neoplastic endometrial outcomes in women 50 or older. AGC-NOS with a squamous cell abnormality and AGC-EC results suggested cervical neoplasia, while AGC-EM results suggested endometrial neoplasia.

CONCLUSIONS

AGC Pap results detected significant numbers of cervical and non-cervical neoplasias. Since 38 of 44 (86%) of AGC-detected carcinomas were endometrial or ovarian, HPV co-testing would not have aided screening in detecting the majority of malignancies diagnosed after AGC Pap results. Verification bias-adjusted Pap screening sensitivity in the laboratory for detection of significant neoplastic cervical disease was 93%.

Reducing the burden of glandular carcinomas of the uterine cervix

Widespread use of the Papanicolaou test for the screening of cervical cancers has lead to a significant decline in overall incidence and mortality rates over the past 3 decades. When different histologic types of cervical cancers are considered and trends are reexamined, it becomes apparent that observed declines are reflective of squamous cell carcinomas predominantly; the rates for adenocarcinomas continue to rise. This rise in incidence may be due to the greater difficulty in screening for glandular precursor lesions that often arise high within the endocervical canal. Reducing the incidence and mortality rates that are associated with adenocarcinomas can be accomplished by using improved screening techniques and large-scale implementation of cervical cancer vaccines that target the predominant oncogenic human papillomavirus types that are associated with adenocarcinoma.

Human papillomavirus (HPV) test and PAP smear as predictors of outcome in conservatively treated adenocarcinoma in situ (AIS) of the uterine cervix

OBJECTIVE

The present study assessed (i) the clinical outcome of patients with conservatively treated cervical adenocarcinoma in situ (AIS), (ii) the accuracy of diagnosing AIS by cytology, colposcopy and histology, as well as (iii) the performance of cervical cytology and HPV testing in detection of residual or recurrent disease after conservatively treated AIS.

METHODS

A series of 42 consecutive women (mean age 40.5 years; range 27-63 years) underwent conservative (cone) treatment of AIS and were prospectively followed up for a mean of 40 months (median 42 months), using colposcopy, PAP smear, biopsy and HPV testing (with hybrid capture II) repeated at 6-month intervals.

RESULTS

In their referral PAP test, only 42.9% of patients had atypical glandular cells (AGC) smear. Colposcopy was unsatisfactory in 54.8% cases and negative in 16.7%. Twenty four patients (57.1%) had AIS as a pure lesions and 18 combined with squamous cell lesion (four had invasive SCC). Persistent or recurrent disease was observed in 17 (40.4%) cases, 19% in patients with free margins, and 65% among those with involved margins on the first conization. In four patients, an adenocarcinoma (AdCa) stage IA1 was diagnosed during the follow-up. HPV testing significantly predicted disease persistence/clearance with OR 12.6 (95% CI 1.18-133.89), while the predictive power of PAP smear did not reach statistical significance at any of the follow-up visits. The combination of PAP smear and HPV testing gives SE of 90.0%, SP 50.0%, PPV 52.9% and NPV 88.9% at first follow-up, and 100% SE and 100% NPV at the second follow-up visit.

CONCLUSIONS

These results suggest that HR-HPV test in conjunction with cytology offers clear advantages over single cytology in monitoring the women conservatively treated for cervical AIS.

Cervical cancer in the developing world

In developed countries, systematic screening programmes have reduced the morbidity and mortality resulting from cervical cancer. Cytological methods of screening have been the mainstay in these countries. Nevertheless, there is scant evidence that cytology-based screening has had any effect in reducing cervical cancer mortality in less-developed countries. In fact, the challenge in less-developed countries is surpassed by the complex array of problems that go far beyond the introduction of simplified technologies. Currently, there are two main issues on this subject: the assessment of simpler screening methods, and the evaluation of different strategies regarding which women to target and the screening interval. Achieving high rates of coverage and compliance of the target population through high-quality procedures has remained the most difficult goal to achieve. Nevertheless, it is believed that creativity, flexibility and well-focused use of resources can reduce the inequitable burden of cervical cancer borne by women in poor countries.

Superficial (early) endocervical adenocarcinoma in situ: a study of 12 cases and comparison to conventional AIS

Although established histologic criteria for the diagnosis of endocervical adenocarcinoma in situ (AIS) have been published, some lesions are not readily classified or present with more subtle degrees of epithelial atypia. Lesions confined to the surface mucosa may be particularly challenging, possibly because they represent early disease. Twelve cases of superficial AIS (SAIS) confined to the surface mucosa or crypt openings culled from the in-house and consultation practices were examined histologically, immunostained for MIB-1 and p16, and analyzed (when possible) for HPV nucleic acids by DNA-DNA in situ hybridization (INFORM). The mean age was 26.7 years for SAIS versus 37.0 years for 42 consecutive cases of conventional AIS from the same practice (P < 0.001). Seven and five were biopsies and conization specimens, respectively. Five coexisted with CIN, four arose in endocervical papillae, and two arose in endocervical polyps. Nuclear hyperchromasia was conspicuous in 10 and mitoses were present in all; however, apoptosis was rare or absent in four, and six exhibited only mild nuclear atypia. Mib-1 staining exceeded 40% in 5 of 7 cases tested, and all (8 of 8) were strongly positive for p16(ink4). Five of five were positive for HPV by ISH with an "integrated" dot-like pattern. SAIS is an early variant of AIS that 1) occurs at a younger mean age, 2) exhibits variable atypia, and 3) arises adjacent to morphologically normal columnar epithelium. Diffuse p16 expression and integrated HPV pattern are identical to that seen in more extensive forms of the disease. Superficial AIS should be suspected in endocervical columnar epithelium with segmental nuclear hyperchromasia with mitotic activity, and confirmed by biomarker staining (p16 and Mib-1) if the pathologist is uncertain of the diagnosis.