Seminars in Diagnostic Pathology

There are many research studies and emerging tools using artificial intelligence (AI) and machine learning to augment flow and mass cytometry workflows. Emerging AI tools can quickly identify common cell populations with continuous improvement of accuracy, uncover patterns in high-dimensional cytometric data that are undetectable by human analysis, facilitate the discovery of cell subpopulations, perform semi-automated immune cell profiling, and demonstrate potential to automate aspects of clinical multiparameter flow cytometric (MFC) diagnostic workflow...

This timely captivating topic is organized and presented in this special issue of the journal of Seminar in diagnostic pathology. This special issue will be dedicated to the utilization of machine learning within the digital pathology and laboratory medicine fields. Special thanks to all the authors whose contributions to this review series has not only enhanced our overall understanding of this exciting new field but will also enrich the reader's understanding of this important discipline.

The field of medicine is undergoing rapid digital transformation. Pathologists are now striving to digitize their data, workflows, and interpretations, assisted by the enabling development of whole-slide imaging. Going digital means that the analog process of human diagnosis can be augmented or even replaced by rapidly evolving AI approaches, which are just now entering into clinical practice. But with such progress comes challenges that reflect a variety of stressors, including the impact of unrepresentative training data with accompanying implicit bias, data privacy concerns, and fragility of algorithm performance...

Over the past decade, many new cancer treatments have been developed and made available to patients. However, in most cases, these treatments only benefit a specific subgroup of patients, making the selection of treatment for a specific patient an essential but challenging task for oncologists. Although some biomarkers were found to associate with treatment response, manual assessment is time-consuming and subjective. With the rapid developments and expanded implementation of artificial intelligence (AI) in digital pathology, many biomarkers can be quantified automatically from histopathology images...

Machine learning (ML) is becoming an integral aspect of several domains in medicine. Yet, most pathologists and laboratory professionals remain unfamiliar with such tools and are unprepared for their inevitable integration. To bridge this knowledge gap, we present an overview of key elements within this emerging data science discipline. First, we will cover general, well-established concepts within ML, such as data type concepts, data preprocessing methods, and ML study design. We will describe common supervised and unsupervised learning algorithms and their associated common machine learning terms (provided within a comprehensive glossary of terms that are discussed within this review)...

Cytology plays an important role in diagnosing and managing human diseases, especially cancer, as it is often a simple, low cost yet effective, and non-invasive or minimally invasive diagnostic tool. However, traditional morphology-based cytology practice has limitations, especially in the era of precision diagnosis. Recently there have been tremendous efforts devoted to apply computational tools and to perform molecular analysis on cytological samples for a variety of clinical purposes. Now is probably the appropriate juncture to integrate morphology, machine learning, and molecular analysis together and transform cytology from a morphology-driven practice to the next level - "SMART" Cytology...

Digital pathology has a crucial role in diagnostic pathology and is increasingly a technological requirement in the field. Integration of digital slides into the pathology workflow, advanced algorithms, and computer-aided diagnostic techniques extend the frontiers of the pathologist's view beyond the microscopic slide and enable true integration of knowledge and expertise. There is clear potential for artificial intelligence (AI) breakthroughs in pathology and hematopathology. In this review article, we discuss the approach of using machine learning in the diagnosis, classification, and treatment guidelines of hematolymphoid disease, as well as recent progress of artificial intelligence in flow cytometric analysis of hematolymphoid diseases...

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No abstract text is available yet for this article.

Ovarian germ cell tumors are a diverse group of benign and malignant neoplasms that occur in a wide age range, but with a predilection for younger age group. The majority are represented by the frequently encountered mature cystic teratomas. Malignant germ cell tumors are uncommon, and in some cases have a characteristic clinical presentation. However, from a histologic standpoint these tumors can sometimes be challenging to diagnose due to overlapping morphology with epithelial, and in some cases sex cord tumors...

Ultrasound-guided fine needle aspiration (USG-FNA) biopsies have traditionally been performed in the radiology department, with radiologists performing the procurement with or without on-site cytotechnologists or pathologists to provide adequacy or diagnostic evaluation of the specimen. However, more recently, these image-guided biopsies have been performed by endocrinologists and now cytopathologists. Starting an USG-FNA service is a big task that requires consideration of multiple factors, including training, certification, privileges, equipment, documentation, information technology (IT) issues, and the overall business plan or financial component...

Advances in digital imaging technology and development of high-speed internet has brought a change in ROSE practice from the traditional in-person to remote evaluation. The rapid expansion of image-guided procedures to obtain tissues for diagnosis and ancillary testing has put a huge demand on cytopathologists' time to perform on-site adequacy assessment. The technology of transmitting digital slide images in real-time via the internet from procedure site that can be viewed remotely and provide preliminary diagnosis, has had a huge impact on the practice of ROSE...

Interventional cytopathology is a unique area of pathology, where cytopathologists play a primary role in obtaining fine needle aspiration biopsies and/or making determinations through rapid on-site evaluations to guide sample procurement in real-time. Unsurprisingly, experience and skill are directly related to success in these endeavors, and both can be fostered with formal instruction. There is a wealth of resources available to aid in teaching interventional cytopathology, including instructional videos, courses, and model phantoms which can help to build familiarity and confidence...

In light of the significant clinical benefits of novel HER2-targeting antibody-drug conjugates in advanced HER2-low expressing breast cancers in recent phases I and III clinical trials, particularly trastuzumab-deruxtecan (T-Dxd), the new "HER2-low" category in breast cancers (breast cancer with a HER2 IHC score of 1+, or 2+ without gene amplification) has gained increasing attention. In the past year, "HER2-low" breast cancers have been under active investigation by both oncologists and pathologists. In this current review, we update the recent cutting-edge research on HER2-low breast cancers, with a focus on the biology of HER2-low breast cancers, the issues on the identification of HER2-low breast cancers by immunohistochemistry in current practice of pathology, and the future directions in this emerging category in breast cancers...

Pathologic examination of the sentinel lymph nodes (SLNs) in patients with breast cancer has been impacted by the publication of practicing changing trials over the last decade. With evidence from the ACOSOG Z0011 trial to suggest that there is no significant benefit to axillary lymph node dissection (ALND) in early-stage breast cancer patients with up to 2 positive SLNs, the rate of ALND, and in turn, intraoperative evaluation of SLNs has significantly decreased. It is of limited clinical significance to pursue multiple levels and cytokeratin immunohistochemistry to detect occult small metastases, such as isolated tumor cells and micrometastases, in this setting...

Breast cancer represents a heterogeneous group of human cancer at both histological and molecular levels. Estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) are the most commonly used biomarkers in clinical practice for making treatment plans for breast cancer patients by oncologists. Recently, PD-L1 testing plays an important role for immunotherapy for triple-negative breast cancer. With the increased understanding of the molecular characterization of breast cancer and the emergence of novel targeted therapies, more potential biomarkers are needed for the development of more personalized treatments...

Papillary lesions of the breast represent a heterogeneous group of neoplasm featuring fibrovascular cores covered by epithelial cells with or without intervening myoepithelial cells. According to the World Health Organization classification of breast tumors, papillary lesions of the breast are further classified into intraductal papilloma (including intraductal papilloma with atypical ductal hyperplasia /ductal carcinoma in situ), papillary ductal carcinoma in situ, encapsulated papillary carcinoma, solid papillary carcinoma (in situ and invasive) and invasive papillary carcinoma...

Breast fibroepithelial lesions, which are composed of biphasic epithelial and stromal proliferations, comprise the fascinating spectrum of fibroadenomas and phyllodes tumours. Common difficulties surrounding their diagnosis include distinguishing between cellular fibroadenomas and benign phyllodes tumours, grading phyllodes tumours, classifying fibroepithelial lesions in paediatric patients, and handling surgical margins. Recent molecular advances have provided insights into the pathogenesis of fibroepithelial lesions and may offer diagnostic, prognostic, and therapeutic information...

Due to the high prevalence of breast cancer in the female, a metastasis from primary breast cancer is usually considered in the differential diagnosis of metastatic carcinoma in the female patient, even for those without a history of breast cancer, as some breast cancers are first diagnosed as metastases. Immunohistochemical analysis for breast cancer markers is the most common way to determine breast cancer origin besides clinical history and histology. In this review, we (1) summarize the commonly used and the newly identified breast cancer markers, including GCDFP-15, mammaglobin, GATA3, SOX10, and TRPS1; (2) point out the strengths and weaknesses of using these markers for breast cancers with luminal/epithelial or basal/myoepithelial differentiation; and (3) recommend diagnostic panels to differentiate breast carcinoma from carcinoma with similar morphology of other origins...

Classification of breast tumors has been evolving in the last decade. Uncommon types of breast neoplasms have been increasingly recognized. While the pathogenesis of a subset of these tumors remains to be ascertained, integration of state-of-the-art knowledge from molecular advancements and clinical practice has enhanced our understanding of these diseases, be they unique to the breast or more frequently seen in other organs. Furthermore, these lesions may have diverse clinical outcomes despite of similar histopathologic and immunophenotypic characteristics or even molecular alterations, thus warranting different clinical management...