Robust Nuclei Segmentation using Statistical Level Set Method with Topology Preserving Constraint
Ayman El-Baz, Jasjit S. Suri in Level Set Method in Medical Imaging Segmentation, 2019
Pathology is a medical specialty which concerns laboratory examination of cells and tissue samples with the purpose of diagnosis and characterization of diseases. More specifically, cytopathological and histopathological examinations of a biopsy or surgical specimen are two main branches of anatomical pathology that are commonly applied to diagnose various diseases, including cancer. Cytopathology (or cytology) refers to the microscopic investigation of samples at the cellular level and is mainly advantageous when quick preparation, staining, and interpretation procedures are needed. Despite the fact that cytopathological imagery are highly beneficial as they provide great cellular detail at low cost, cytopathological examinations alone are not sufficient for accurate diagnosis purposes. For instance, they cannot indicate whether the cancer cells are spreading into and damaging surrounding tissues. Therefore, to obtain higher diagnostic accuracy, the preliminary cytopathological tests must be confirmed by the so-called histopathological (or histological) assessments for which the overall tissue architecture is evaluated. Pathologists usually make diagnostic interferences by visual inspection of cells based on their morphological features and architecture, such as shape, position, size, number, etc. Although still being considered as the gold standard, manual examination of biological images is tedious work which requires many hours of human labor. This highlights the requirement for an automatic system that accurately measures these features in a few seconds.
Non-melanoma skin cancer
Pat Price, Karol Sikora in Treatment of Cancer, 2014
There are four generally accepted methods for obtaining tissue diagnosis. These are: shave biopsy, punch biopsy, cytology or definitive surgical excision. A shave biopsy usually is adequate for raised lesions such as nodular BCC. Punch biopsy is effective for sampling superficial BCC, for which shave or excision would be technically inappropriate. An excision biopsy may be used to sample deep dermal and subcutaneous tissue. A comparison of shave biopsy versus punch biopsy was performed retrospectively in 86 cases showing that the two techniques have equivalent diagnostic accuracy rates. Cytology provides a rapid alternative to either punch biopsy or shave biopsy, and it can yield a diagnosis during the initial out-patient appointment. The accuracy of cytology in eyelid lesions suspected clinically to be BCCs was compared retrospectively in 20 lesions from 17 consecutive patients who underwent cytology followed by excision biopsy.99 The sensitivity of cytology for the diagnosis of BCC was 92%. This was compared with a second group of 26 clinical BCCs from 22 consecutive patients who had an incisional biopsy and histological examination followed by excision with histological confirmation, in which the sensitivity was 100% and the accuracy was 96%. Cytology is sufficiently accurate to plan excision and reconstructive surgery when the diagnosis can be confirmed histologically, but may not be sufficiently sensitive for conservative regimens such as RT because of the small risk of false-negative diagnosis; however, it may be accepted clinically for subsequent diagnoses.99
Sexually Transmissible Viral Pathogens: Human Papillomaviruses and Herpes Simplex Viruses
Attila Lorincz in Nucleic Acid Testing for Human Disease, 2016
Published data show that the clinical sensitivity of conventional cytology is low — in the range of 50 to 60%.15,16 Most Pap testing in the United States is now performed via liquid cytology (e.g., ThinPrep), which appears to show moderately higher clinical sensitivity than conventional cytology — in the range of 60 to 85%17,18 — but potentially lower specificity. However, none of these cytology tests appears to approach the 95 to 100% clinical sensitivity required for a truly effective screening program.
PAX1 and SEPT9 methylation analyses in cervical exfoliated cells are highly efficient for detecting cervical (pre)cancer in hrHPV-positive women
Published in Journal of Obstetrics and Gynaecology, 2023
Lulu He, Xiping Luo, Qiaowen Bu, Jing Jin, Shuai Zhou, Shaoyi He, Liang Zhang, Yu Lin, Xiaoshan Hong
Around the world, cytology and/or HPV-based screening are currently the most commonly used methods for cervical cancer screening (Partanen et al.2021). There is strong evidence that hrHPV testing has superior sensitivity for detecting cervical (pre)cancer (Elfstrom et al.2014). However, 90% of HPV infections clear the virus spontaneously; thus, HPV testing cannot identify transient infections (Giorgi-Rossi et al.2012, Vink et al.2020). The combined use of cytology and HPV testing maximises sensitivity, while increasing specificity to detect certain cervical (pre)cancers (Sahasrabuddhe et al.2011). However, the obvious disadvantages of cytology testing include high false-negative rates and the fact that cytology testing is easily affected by sampling, i.e. laboratory and pathologist-subjective interpretations. To date, even high-quality Pap cytology may miss >30% of cervical (pre)cancer cases (Lorincz 2016). Thus, it is important to find an efficient triage strategy that is sensitive enough to detect cervical (pre)cancer but that has high enough specificity to rule out HPV-positive women without potential for progression.
Advances in technologies for cervical cancer detection in low-resource settings
Published in Expert Review of Molecular Diagnostics, 2019
Kathryn A. Kundrod, Chelsey A. Smith, Brady Hunt, Richard A. Schwarz, Kathleen Schmeler, Rebecca Richards-Kortum
In high-resource settings, the standard of care for cervical cancer screening includes cervical cytology and/or high-risk HPV DNA or RNA testing, as the vast majority of cervical cancer is caused by infection with HPV. Cytology, commonly referred to as the Pap test, involves examining the morphology of exfoliated cervical cells under a microscope and generally has a low sensitivity (53–55.4%) and high specificity (84.2–94.5) [9–12]. Cytology performance varies greatly, even within the United States due to interpretative variability [13]. In low-resource settings, the challenge of achieving high-quality cytology is greater because of a lack of medical capacity and even logistical capacity to get high-quality reagents into the country. Therefore, sensitivity may be even lower in low-resource regions than in higher-resource settings, where it is at best moderate, because validated Pap staining and/or liquid-based cytology is not available. As such, quality assurance of cytology is important to achieve similar preventive impact on cervical cancers compared with validated cytological methods. To compensate for low sensitivity in the United States, cytology testing efficacy comes from repeated, regular screening [14]. HPV DNA testing, in comparison, has relatively higher sensitivity (90.2–96.1%) and lower specificity (84.2–94.5%) in screening populations [9–11,15].
Diagnostic accuracy of preoperative palpation- versus ultrasound-guided thyroid fine needle aspiration cytology: an observational study
Published in Postgraduate Medicine, 2020
Ibrahim Taha, Hassan Al-Thani, Ayman El-Menyar, Mohammad Asim, Maryam Al-Sulaiti, Abdelhakem Tabeb
In the present study, 70% of palpation-guided and 55% of ultrasound-guided FNA smears had benign cytology. This is in agreement with other reports showed benign cytology (around 70%) to be the most frequent findings of the FNA biopsies [1]. Furthermore, the reported risk of malignancy among cases with benign cytology on FNA was low (0–3%) [1]. Therefore, patients with benign nodules on US-guided FNA are mostly treated nonoperatively; without further immediate diagnostic work-up [14]. With respect to benign cytology results, our study showed that the rate of malignancy was comparable among the US-guided and palpation-guided groups. This shows that there is a risk of false negative results associated with cytology reporting which needs to be carefully considered for long-term management and follow-up [29].