Christos Meristoudis

Identification of Women for Referral to Colposcopy by Neural Networks: A Preliminary Study Based on LBC and Molecular Biomarkers

Objective of this study is to investigate the potential of the learning vector quantizer neural network (LVQ-NN) classifier on various diagnostic variables used in the modern cytopathology laboratory and to build an algorithm that may facilitate the classification of individual cases. From all women included in the study, a liquid-based cytology sample was obtained; this was tested via HPV DNA test, E6/E7 HPV mRNA test, and p16 immunostaining. The data were classified by the LVQ-NN into two groups: CIN-2 or worse and CIN-1 or less. Half of the cases were used to train the LVQ-NN; the remaining cases (test set) were used for validation. Out of the 1258 cases, cytology identified correctly 72.90% of the CIN-2 or worst cases and 97.37% of the CIN-1 or less cases, with overall accuracy 94.36%. The application of the LVQ-NN on the test set allowed correct classification for 84.62% of the cases with CIN-2 or worse and 97.64% of the cases with CIN-1 or less, with overall accuracy of 96.03%. The use of the LVQ-NN with cytology and the proposed biomarkers improves significantly the correct classification of cervical precancerous lesions and/or cancer and may facilitate diagnosis and patient management.

mRNA and DNA Detection of Human Papillomaviruses in Women of All Ages Attending Two Colposcopy Clinics

Objective HPV infection is a common finding, especially in young women while the majority of infections are cleared within a short time interval. The aim of this study was to examine the efficacy of HPV DNA and mRNA testing in a population attending colposcopy units of two University hospitals. Methods 1173 liquid based cervical samples from two colposcopy clinics were tested for HPV DNA positivity using a commercial typing kit and HPV E6/E7 mRNA positivity with a flow cytometry based commercial kit. Statistic measures were calculated for both molecular tests and morphological cytology and colposcopy diagnosis according to histology results. Results HPV DNA, high-risk HPV DNA, HPV16 or 18 DNA and HPV mRNA was detected in 55.5%, 50.6%, 20.1% and 29.7% of the cervical smears respectively. Concordance between the DNA and the mRNA test was 71.6% with their differences being statistically significant. Both tests’ positivity increased significantly as lesion grade progressed and both displayed higher positivity rates in samples from women under 30 years old. mRNA testing displayed similar NPV, slightly lower sensitivity but significantly higher specificity and PPV than DNA testing, except only when DNA positivity for either HPV16 or 18 was used. Conclusions Overall mRNA testing displayed higher clinical efficacy than DNA testing, either when used as a reflex test or as an ancillary test combined with morphology. Due to enhanced specificity of mRNA testing and its comparable sensitivity in ages under 25 or 30 years old, induction of mRNA testing in young women could be feasible if a randomized trial verifies these results.

Using classification and regression trees, liquid-based cytology and nuclear morphometry for the discrimination of endometrial lesions

‘The objective of this study is to investigate the potential of classification and regression trees (CARTs) in discriminating benign from malignant endometrial nuclei and lesions. The study was performed on 222 histologically confirmed liquid based cytological smears, specifically: 117 benign cases, 62 malignant cases and 43 hyperplasias with or without atypia. About 100 nuclei were measured from each case using an image analysis system; in total, we collected 22783 nuclei. The nuclei from 50% of the cases (the training set) were used to construct a CART model that was used for knowledge extraction. The nuclei from the remaining 50% of cases (test set) were used to evaluate the stability and performance of the CART on unknown data. Based on the results of the CART for nuclei classification, we propose two classification methods to discriminate benign from malignant cases. The CART model had an overall accuracy for the classification of endometrial nuclei equal to 85%, specificity 90.68%, and sensitivity 72.05%. Both methods for case classification had similar performance: overall accuracy in the range 94–95%, specificity 95%, and sensitivity 91–94%. The results of the proposed system outperform the standard cytological diagnosis of endometrial lesions. This study highlights interesting diagnostic features of endometrial nuclear morphology and provides a new classification approach for endometrial nuclei and cases. The proposed method can be a useful tool for the everyday practice of the cytological laboratory. Diagn. Cytopathol. 2014;42:582–591.

Promoter Methylation of p16INK4A, hMLH1, and MGMT in Liquid-Based Cervical Cytology Samples Compared with Clinicopathological Findings and HPV Presence

Cervical cancer is a common cancer inflicting women worldwide. Even though, persistent infection with oncogenic Human Papillomavirus (HPV) types is considered the most important risk factor for cervical cancer development, less than 5% of women with HPV will eventually develop cervical cancer supporting that other molecular events, like methylation-dependent inactivation of tumor suppressor genes, may cocontribute in cervical carcinogenesis. We analyzed promoter methylation of three candidate genes (p16, MGMT, and hMLH1) in 403 liquid-based cytology samples. Methylation was commonly identified in both benign and pathologic samples and correlated with higher lesion grade determined by cytological, colposcopical, or histological findings, with HPV DNA and mRNA positivity of specific HPV types and p16INK4A protein expression. Overall accuracy of methylation is much lower than traditional diagnostic tests ranking it as an ancillary technique with more data needed to identify the exact value of methylation status in cervical carcinogenesis.

Molecular epidemiology of HPV infection using a clinical array methodology in 2952 women in Greece

The molecular epidemiology of human papillomavirus (HPV) infection in a sample of Greek women (n = 2952, mean age 42.2 ± 13.3 years) was examined. HPV prevalence was 50.7% (95% confidence interval, 48.8-52.6). The most frequent HPV types were HPV 53, 51 and 66 (10.2%, 9.4% and 9.3%, respectively). HPV positivity was associated with age, age of sexual debut, number of sexual partners and duration of sexual relationship, while marriage or multiparity protected against infection (all p <0.001). Follow-up of this cohort will assist in predicting the effect of vaccination with the new HPV vaccines on future screening with HPV-based tests for cervical cancer.

Simultaneous occurrence of Warthin-like papillary carcinoma and lymphoma of the mucosa associated lymphoid tissue in Hashimoto thyroiditis

Simultaneous occurrence of papillary carcinoma and lymphoma in the thyroid is extremely rare, only three cases having so far been reported. In a 51-year-old woman with thyroid nodules, papillary carcinoma was diagnosed in an ultrasound-guided fine needle aspiration of a right lobe nodule. Subsequent thyroidectomy revealed a 1 cm large, Warthin-like papillary carcinoma (figure 1), whereas a 0.7 cm focus of classical type papillary carcinoma was found in the lower third of the right lobe. Hashimoto thyroiditis was also seen (figure 2). Moreover, a 1.2 cm area with scant thyroid follicles and large lymphoid follicles surrounded by small lymphocytes was found in the left lobe. The lymphoid infiltrate showed immunopositivity for both CD20 and CD43; …

Internal quality control in an academic cytopathology laboratory for the introduction of a new reporting system for endometrial cytology

To evaluate reproducibility of a reporting system for endometrial cytology.

B-lymphocyte, Macrophage and Mast Cell Density in the Stroma Underlying HPV-Related Cervical Squamous Epithelial Lesions and their Relationship to Disease Severity: an Immunohistochemical Study

Introduction: B lymphocyte, macrophage and mast cell densities in the stroma underlying cervical low and high grade squamous intraepithelial lesions (LSIL and HSIL) and squamous cell carcinoma (SCC) in 200 tissue samples, with concomitant HPV typing, was assessed, in order to examine their relationship to disease status and progression. Methods: Sections from 215 cervical specimens (149 LSIL, 38 HSIL, 13 SCC and 15 normal cervical mucosae) were immunostained for B lymphocytes (CD20), macrophages (CD68) and mast cells (CD117). The number of cells per high power field (henceforth called density) in the stroma underlying epithelial lesions was assessed. Statistical analysis was performed using four ordinal scale groups of increasing severity (normal, LSIL, HSIL and SCC). Results: Densities of all three cell types had a statistically significant, proportional correlation to disease severity, more so for B lymphocytes. Increased density of any cell type is linked to an increase in the densities of the remaining two. A statistically significant difference in B lymphocyte and mast cell density was found between LSIL and HSIL. No cell type density was found to be predictive of the outcome of LSIL. No relationship with HPV type was found. Discussion: Increased B lymphocyte and mast cell density in the stroma underlying cervical HSIL and SCC compared to LSIL suggests a possible relationship of both cell types to progression of cervical SIL. No predictive value of the density of any cell type was found concerning the outcome of LSIL. Immunohistochemistry may contribute to elucidate the relationship of local immunity effector cells to cervical epithelial lesions.