Cytology, liquid-based cytology and automation

Computational pathology: A survey review and the way forward

Computational Pathology (CPath) is an interdisciplinary science that augments developments of computational approaches to analyze and model medical histopathology images. The main objective for CPath is to develop infrastructure and workflows of digital diagnostics as an assistive CAD system for clinical pathology, facilitating transformational changes in the diagnosis and treatment of cancer that are mainly address by CPath tools. With evergrowing developments in deep learning and computer vision algorithms, and the ease of the data flow from digital pathology, currently CPath is witnessing a paradigm shift. Despite the sheer volume of engineering and scientific works being introduced for cancer image analysis, there is still a considerable gap of adopting and integrating these algorithms in clinical practice. This raises a significant question regarding the direction and trends that are undertaken in CPath. In this article we provide a comprehensive review of more than 800 papers to address the challenges faced in problem design all-the-way to the application and implementation viewpoints. We have catalogued each paper into a model-card by examining the key works and challenges faced to layout the current landscape in CPath. We hope this helps the community to locate relevant works and facilitate understanding of the field's future directions. In a nutshell, we oversee the CPath developments in cycle of stages which are required to be cohesively linked together to address the challenges associated with such multidisciplinary science. We overview this cycle from different perspectives of data-centric, model-centric, and application-centric problems. We finally sketch remaining challenges and provide directions for future technical developments and clinical integration of CPath. For updated information on this survey review paper and accessing to the original model cards repository, please refer to GitHub. Updated version of this draft can also be found from arXiv.

Screening Methods for Cervical Cancer

Cervical cancer seriously affects the health of women worldwide. Persistent infection of high-risk HPV (Human Papilloma Virus) can lead to cervical cancer. There is a great need for timely and efficient screening methods for cervical cancer. The current screening methods for cervical cancer are mainly based on cervical cytology and HPV testing. Cervical cytology is made of Pap smear and liquid-based cytology, while HPV testing is based on immunological and nucleic acid level detection methods. This review introduces cervical cancer screening methods based on cytology and human papillomavirus testing in detail. The advantages and limitations of the screening methods are also summarized and compared.

Correlation of immediate prevalence of cervical precancers and cancers with HPV genotype and age in women with atypical glandular cells cytology: A retrospective analysis of 369 cases

BACKGROUND

This study aims to assess the immediate risk of cervical precancers and cancers in women with atypical glandular cells (AGC) cytology, based on high-risk human papillomavirus (hrHPV) genotypes and age.

METHODS

A retrospective analysis was conducted on 369 cases of AGC with immediate follow-up biopsy results, including 299 AGC-not otherwise specified (NOS) and 70 AGC-favor neoplastic (FN).

RESULTS

Among the 369 AGC cases, 127 tested positive for hrHPV (34.4%). The predominant high-risk type was other 11 genotypes (44.1%), followed by 16+ (29.1%), 18/45+ (26.0%), and 16 and 18/45 double-positive (0.79%). Precancers and cancers were detected in 30.4% (112 of 369) and 9.8% (36 of 369) of cases, respectively. The HPV-18/45+ group had notably higher adenocarcinoma in situ and adenocarcinoma (AIS+) prevalence compared to other 11 genotype groups (p < .0001 and p = .001, respectively). The HPV-16+ group showed significantly higher high-grade cervical squamous epithelial lesion and squamous cell carcinoma prevalence than other 11 genotype groups (p < .0001 and p = .017, respectively). Using 40-year cutoff, older women had significantly higher prevalence of abnormal glandular lesion+ lesions (17.6% vs. 7.6%, p = .005) and adenocarcinoma (AC) (12.4% vs. 2.5%, p = .001). Using 50-year cutoff, older women had higher prevalence of squamous cell carcinoma (SCC) (3.3% vs. 0.4%, p = .042) and AC (15.2% vs. 5.8%, p = .005). Subgroup analysis revealed that AGC-FN women showed more severe cervical pathology than AGC-NOS women (p < .001).

CONCLUSIONS

AGC women have a significantly increased risk of cervical precancerous lesions and cancer. HPV genotyping and patient age factors need to be taken into consideration in the clinical management process of AGC patients.

ThinPrep® imaging system-assisted vs manual screening of urinary cytology slides in the detection of the "suspicious for high-grade urothelial carcinoma" category

BACKGROUND

The ThinPrep® Imaging System (TIS) is a Food and Drug Administration-approved review system for cervical cytopathology, where it has been shown to increase performance over manually reviewed slides. Application of the TIS to urinary cytology has only been reported in a single study, in 2013.

METHODS

We aimed to compare the agreement of two cytotechnologists' and a pathologist's manual screening (dots) with the fields of view (FOVs) selected by the TIS. We also aimed to track cases in which the TIS could identify missed abnormals and reduce the false-negative fraction. Electronically marked TIS fields (EMTFs) suspicious for high-grade urothelial carcinoma (SHGUC) were controlled by follow-up cystoscopy and histology, where available.

RESULTS

A total of 826 consecutive specimens were studied. Of those, 94 (11.4%) were unreadable by the TIS. There were 710 possible comparisons, of which 380 (53.5%) received no dot after manual screening. Of the 330 remaining slides, 149 (45.1%) had at least one dot matching with the TIS FOVs. After TIS reading, EMTFs were noted in 13 of 636 (2.0%) negative cytology cases. Surveillance showed that 3/13 (23.1%, 0.4% of the 710 possible comparisons) of those cases matched with high grade urothelial carcinoma (HGUC), whereas 6/13 (46.1%, 0.8% of the 710 possible comparisons) had negative follow-up at 24 months, and 4/13 (30.8%) were lost for follow-up.

CONCLUSION

The TIS increases the detection rate of SHGUC cells, potentially leading to a slight decrease in the false-negative fraction, but at the expense of a slight but larger increase in the number of false-positive cases. These findings stress the importance of a careful approach to the evaluation of the FOVs.

Direct hysteroscopic endometrial sampling and pipelle sampling in perimenopausal women

BACKGROUND

Abnormal uterine bleeding is a common cause of hospital admission in perimenopausal women. It can be the first sign of many diseases such as endometrial cancer and endometrial hyperplasia. Endometrial sampling is valuable in early diagnosis and treatment. Although hysterectomy is the gold standard in the diagnosis of endometrial pathology, it is not considered an acceptable method for diagnosis. With the principle of "see and treat, hysteroscopy seems to be the most successful method.

METHODS

After obtaining the necessary ethics committee approval, we obtained liquid-based cytology samples of our perimenopausal patients who frequently applied to our outpatient clinic with abnormal uterine bleeding. To conduct endometrial sampling of our patients, we used pipelle aspiration method in our 75-disease group and direct hysteroscopic sampling method in our other 75 disease group. We then compared the pre- and postoperative pathology results.

RESULTS

There was no statistically significant difference between preoperative and postoperative pathological results in both pipelle and hysteroscopic sampling groups.

CONCLUSIONS

Evaluation of endometrial pathologies by hysteroscopic method and pipelle method has high sensitivity and specificity. Gynecologists may determine the method preference according to the status of the health system together with their patients.

Rehydration of Air-Dried Smears with Normal Saline: An Alternative for Conventional Wet Fixation Method in Cervical Cytological Study

Context:

Papanicolaou (Pap) smear is an effective exfoliative cytological investigation done for early recognition of cervical cancer. It also plays role in diagnosis of inflammatory lesions of cervix.

Aims:

The aim of this study is (1) to compare the cytomorphological features in conventional Pap smear (C-PAPS) and rehydrated air-dried Pap smear (RADPS) and (2) to evaluate the efficacy of RADPS in cytodiagnosis of cervical lesion by comparing with cytomorphological features of conventional wet-fixed Pap smear.

Subjects and Methods:

Paired cervical smears were prepared for 247 patients. One was labeled as C-PAPS and another was labeled as RADPS. Comparison of both smears was done for various cytomorphological parameters.

Results:

Out of 247 smears, 2.4% RADPS and 7.3% C-PAPS were reported as unsatisfactory. Red blood cell (RBC) background was present in 2% of RADPS and 42% of C-PAPS. Cytolysis and air-drying artifact were observed more in C-PAPS amounting to 2% and 4% in RADPS and 11% and 15% in C-PAPS. Cytoplasmic staining (97% RADPS vs. 94% C-PAPS) was superior in RADPS. Cell border, nuclear border, and chromatin of squamous and endocervical cells were better appreciated on RADPS compared to C-PAPS, and also statistically significant difference was observed.

Conclusion:

Rehydrated air-dried technique can be satisfactory alternative for conventional wet fixation method which can be followed routinely or in conjugation with C-PAPS, especially in cervical screening programs.

Clinical comparison of liquid-based and conventional cytology of oral brush biopsies: a randomized controlled trial

Background

Exfoliative cytology performed on oral brush samples can help dentists to decide, whether a given oral lesion is (pre-) malignant. The use of non-invasive brush biopsies as an auxiliary tool in the diagnosis of oral mucosal lesions has gained renewed interest since improvements in cytological techniques such as the development of adjuvant diagnostic tools and liquid-based cell preparation techniques.

Methods

The aim of this study was to compare the quality of two different preparation techniques (cell collectors): the conventional transfer procedure to glass slides and the so-called liquid-based cytology preparation method. Cell smears were collected from 10 orally healthy individuals (mean age: 24 years) from the palatine mucosa at two different times (baseline and 4 weeks later). Slides of both techniques were stained by Giemsa (n = 40) and May-Gruenwald Giemsa (n = 40). The statistical analysis was performed with Excel.

Results

On specimen analysis, the liquid-based cytology showed statistically significant improvement compared to conventional glass sides (p < 0.001). Thin layers, which were performed by liquid-based cytology showed significantly better results in the parameters (p < 0.001): uniform distribution, cellular overlapping, cellular disformation, mucus, microbial colonies and debris. The conventional glass slides approach showed more cell overlapping and contamination with extraneous material than thin layers, which were performed by Orcellex® Brush cell collectors.

Conclusions

Both techniques are diagnostically reliable. The liquid-based method showed an overall improvement on sample preservation, specimen adequacy, visualization of cell morphology and reproducibility.

Liquid-based cytology simplifies cell collection due to easier handling and less transfer errors by dentists.

Exploration of treatment strategies for normal cytology smears with reactive cellular changes

OBJECTIVE

To evaluate the use of high-risk humanpapillomavirus (HR-HPV) DNA testing in women who have normal cytology result with reactive cellular changes to identify high risk patients of developing precancerous cervical lesions and cervical cancer.

STUDY DESIGN

Outpatient patients with normal liquid-based cytology (LCT) results showing reactive cellular changes (case group, n=1085) and normal LCT without reactive cellular changes (control group, n=1085) were recruited from cervical clinics at the International Peace Maternity & Child Health Hospital from January 2012 to December 2013. The HPV status and cervical biopsy pathology results were analyzed.

RESULTS

The HR-HPV positive rate of the case group (598/1085) was higher than that of the control group (163/1085) (P<0.001). HR-HPV prevalence among CIN1, CIN2, CIN3 and cervical cancer was 73%, 87%, 100%, and 100% respectively (P<0.05). In patients with positive HR-HPV results, more CIN2+ were found significantly in case group (37/598) than those in control group (3/163), P=0.027. The sensitivity of diagnosis of CIN2+ lesions by HR-HPV testing was 92.5%, the specificity was 36%, the positive predicted value was 8.6%, and the negative predictive value was 98.6%. The incidence of CIN2+ lesions was not different among different age groups (P>0.05).

CONCLUSION

Reactive cellular changes in normal cervical smears should be further investigated. HR-HPV testing could be used as an effective triage in cases of reactive cellular changes. Colposcopy is recommended for those cases showing reactive cellular changes combined with HR-HPV positivity to reduce the risk of failure to diagnose cervical cancer and precancerous lesions.

Malignant mixed Müllerian tumor with an extensive squamous-cell carcinomatous component: a potential pitfall in liquid-based cervical cytology

BACKGROUND

Malignant mixed Müllerian tumors (MMMTs) are aggressive tumors arising in the female lower genital tract and characterized by the presence of both a malignant epithelial and a mesenchymal component. Here, we report a case of an MMMT of the uterine corpus with an extensive squamous-cell carcinomatous component processed by liquid-based cytology (LBC).

CASE REPORT

An 84-year-old woman with a prior history of anal squamous-cell carcinoma, who complained of vaginal bleeding, was discovered to have a mass protruding from the uterine cervix. A Papanicolaou (Pap) test was performed and the LBC (ThinPrep) preparation showed a background of neutrophils and cellular debris. Atypical cells were identified that presented with hyperchromatic nuclei, nuclear membrane irregularities, multinucleation and abundant cytoplasm with focal keratinization. Scattered nucleolated malignant elements were also identified. The cytological diagnosis resulted in 'suspicious for squamous-cell carcinoma', favoring primary cervical carcinoma rather than extracervical (anal) carcinoma. The histological examination showed that it was an MMMT with an extensive squamous-cell carcinomatous component.

CONCLUSION

This case illustrates the potential diagnostic pitfall of MMMTs with extensive squamous-cell carcinomatous components in LBC Pap smears. Cytopathologists should keep in mind this diagnostic possibility in postmenopausal women who experience vaginal bleeding or spotting.