Advances In Anatomic Pathology最新文献

The International Consensus Classification (ICC) updated in 2022 the World Health Organization (WHO) classification of hematopoietic tumors (2016 revision of the 4th edition WHO classification). Although the major categories of myeloid neoplasms remained unchanged from the prior WHO classification, many disease entities including those in the myeloproliferative neoplasm (MPN) and myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) categories underwent updates. For all these disease subtypes, a careful integration of clinicopathologic findings and molecular data led to improved diagnostic definitions. Although the classification of MPNs received only minor changes, these included a simpler definition of accelerated phase of chronic myeloid leukemia. For the MDS/MPN group, in addition to the presence of one or more increased peripheral blood cell counts as evidence of myeloproliferative features, concomitant cytopenia as evidence of ineffective hematopoiesis is now an explicit diagnostic requirement for all the entities included in this category. The presence of specific mutations in the appropriate clinicopathologic context is now included in the diagnostic criteria for some of the MPN and MDS/MPN entities. This review aims to briefly discuss the diagnostic approach to MPNs and MDS/MPNs according to the ICC.

The International Consensus Classification (ICC) of myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) expands on the work of prior classifications to refine the diagnostic criteria for MDS and AML and to identify specific genetic disease subtypes. This review summarizes the approach to the diagnosis of MDS and AML from the ICC perspective. For MDS, the significance of detecting mutations in SF3B1 , usually associated with ring sideroblasts, as well as the poor prognosis of mutations of TP53 are now included. For AML, new genetic categories are included, and the classification now incorporates additional clinically significant gene mutations by recognizing AML with TP53 mutation and AML with mutations in genes associated with prior therapy or MDS. Finally, the new category of MDS/AML is introduced for adult patients without recurrent de novo genetic abnormalities with 10% to 19% peripheral blood or bone marrow blasts that allow for more treatment flexibility based on clinical findings. While the increase in genetic categories and changes in blast cell requirements can be confusing, a stepwise approach is provided to allow easy use of the classification.

Over the past few years, several fusion genes have been reported in dermal-based tumors, resulting in the activation of the microphthalmia (MITF) signalling pathway and a melanocytic phenotype by immunohistochemistry. The best-studied example of these tumors is clear cell sarcoma, which rarely may present as a primary dermal tumor. These tumors are characterized by EWSR1 gene rearrangements, typically with ATF1 and less commonly CREB1. More recently reported cutaneous tumors show gene fusions involving CRTC1::TRIM11, ACTIN::MITF, MITF::CREM, and MED15::ATF1. While the entities in this tumor group share many features, they show subtle distinguishing features, including clinical presentation, histopathologic features, immunophenotype, and outcome. The following overview provides a detailed discussion of these rare tumors with emphasis on differentiating features and differential diagnosis.

The International Consensus Classification (ICC) of myeloid and lymphoid neoplasms follows the precedent set in the Revised European-American lymphoma classification for modern lymphoma classifications by defining specific diseases on the basis of all the available morphologic, immunophenotypic, genetic, and clinical findings. Primary cutaneous lymphomas exhibit a broad range of clinical behavior ranging from lesions which spontaneously regress to those which run an aggressive, often fatal course. Accurate separation of entities is therefore essential for prognostication and to ensure appropriate treatment is administered. However, despite marked differences in clinical course, many subtypes of primary cutaneous lymphoma exhibit remarkably similar, often overlapping, and sometimes indistinguishable pathologic features. While molecular analysis has furthered our understanding of some of these disease entities, it does not yet facilitate robust distinction. Thus, clinical correlation retains a central role in both the diagnosis and classification of primary cutaneous lymphoma. This review aims to draw attention to problem areas in differential diagnosis and hopefully offer some practical suggestions for resolving difficult cases. It will also highlight recent advances in the field and discuss how they reinforce the current classification system and how they might impact of future classifications and treatment strategies.

Follicular lymphoma (FL) is a mature B cell neoplasm classically characterized by B cells harboring the t(14;18) IGH::BCL2 leading to the overexpression of BCL2 in most cases. Conventional FL occurs in lymph nodes and typically shows a follicular B-cell proliferation expressing at least one germinal center marker. Two early lesions closely related to conventional FL are recognized as variants, namely in situ follicular neoplasia (ISFN), and duodenal-type follicular lymphoma (DTFL). FL lacking BCL2 rearrangement ( BCL2 -R negative) accounts for around 10% to 15% of FLs and constitutes a heterogeneous group of FLs. Most of these alternative forms of FL are considered as distinct entities separate from conventional FL in the 2022 International Consensus Classification. This review aims to summarize the key pathologic and diagnostic features of FL conventional and its alternative forms as well as further emphasize the increasing role of molecular studies in the diagnostic work-up.

Aggressive B-cell lymphomas are a biologically and clinically very heterogeneous group of tumors that may be related to different stages of B-cell differentiation development. This review aims to summarize recent advances in the understanding of these tumors with a focus on the practical approach to the diagnosis of these entities. We analyze the defining characteristics of the different subtypes of aggressive B-cell lymphomas, including nodal and extranodal diffuse large B-cell lymphoma, virus-associated lymphomas, terminally differentiated B-cell lymphomas, high-grade B-cell lymphomas, and Burkitt lymphoma. This review particularly explores the integration of morphologic, immunophenotypic, and genetic data that refine diagnostic accuracy and prognostic stratification, underscoring the necessity for a standardized approach in clinical practice. By synthesizing current knowledge, this review aims to enhance the understanding of aggressive B-cell lymphomas within the context of the evolving classification system, paving the way for future research and clinical advancements.

In recent decades, there have been many meaningful contributions to the pathology literature with respect to T-cell lymphoma pathogenesis and biology and improved diagnostics. We know more about disease classification, clinical characteristics, immunophenotype, and genetics than ever before, and yet diagnosis of nodal T-cell lymphomas continues to be a challenging exercise. Complicating interpretation are the many non-neoplastic mimickers of peripheral T-cell lymphoma including drug effects, viruses, autoimmune, and idiopathic conditions, that must be considered when faced with an abnormal lymph node biopsy. The number of immunohistochemical stains required to make a diagnosis of T-cell lymphoma is not standardized and may be exhaustive, requiring judicious use of tissue sections. Clonality studies may contribute to the diagnosis, though questions remain about test modality, when to exercise interpretive caution, and what to do if a clone cannot be demonstrated. Use of next generation sequencing in the diagnosis of nodal T-cell lymphomas is increasing, but how the data can be practically applied to diagnosis is still under examination. The goal of this paper is to consider nodal T-cell lymphoma diagnosis and classification in a modern context, using a question-and-answer format to capture the interest of the reader and address common pathology consultation queries.

This review focuses on the purported applications of multimodal Gen-AI models for anatomic pathology image analysis and interpretation to predict future directions. A scoping review was conducted to explore the applications of multimodal Gen-AI models in advancing histopathology image analysis. A comprehensive search was conducted using electronic databases for relevant articles published within the past year (July 1, 2023 to June 30, 2024). The selected articles were critically analyzed to identify and summarize the applications of multimodal Gen-AI in anatomic pathology image analysis. Multimodal Gen AI models reported in the literature claim moderate to high accuracy on tasks including image classification, segmentation, and text-to-image retrieval. This review demonstrates the potential of multimodal Gen AI models for useful applications in pathology, including assisting with diagnoses, generating data for education and research, and detection of molecular features from anatomic pathology images. These models use data from a few academic institutions thus they require validation on diverse real-world data. There is an urgent need to build consensus models for optimal model performance through multicenter collaboration using a federated learning approach and the use of carefully curated synthetic anatomic pathology data. These models also need to achieve reliability, generalizability and meet the standards required for clinical use. Despite the rigorous need for evaluation and the need to address genuine concerns, multimodal GenAI models present a promising perspective for the advancement and scalability of anatomic pathology.