Human Pathology Reports最新文献

Salivary gland neoplasms are rare and represent a diverse group of tumors. Fine-needle aspiration is a cost effective approach that has been widely applied in preoperative diagnosis of salivary gland lesions to guide clinical management. The wide diversity of entities, significant morphological overlap and limited cellularity make salivary gland cytology challenging. A cellular and architectural pattern-based approach can help narrow down the differential diagnoses. In the meantime, molecular understanding has resulted in a rapid expansion and redefining of salivary gland neoplasms. Herein, we reviewed salivary gland cytology which focused on four patterns: basaloid, oncocytic/oncocytoid, mucinous/cystic/secretory and spindle, along with updated immunohistochemical and molecular features.

This review summarizes changes and updates in the most recently published 2023 Bethesda System for Thyroid Cytopathology (TBSRTC). Further, the review focuses on challenges and pitfalls encountered in cytologic assessment of thyroid fine needle aspiration (FNA) specimens, with an emphasis on atypia of undetermined significance (TBSRTC category III) and the impact on risk of malignancy (ROM) among TBSRTC diagnostic categories following implementation of the terminology noninvasive follicular neoplasm with papillary-like nuclear features (NIFTP). The role of molecular testing as an adjunct to FNA cytology will be discussed.

Cytopathologists have assumed a progressively pivotal role in diagnosing lymphoproliferative disorders. This review outlines a concise approach to the work-up of suspected lymphoma in cytopathology practice, emphasizing the integration of cytomorphologic evaluation with ancillary studies. These include the application of rapid onsite evaluation (ROSE) for proper specimen triage, immunophenotyping through flow cytometry (FC) and immunohistochemistry (IHC), and molecular studies on cytology/small biopsy specimens. Furthermore, the review provides a brief introduction to the forthcoming WHO Reporting System in Lymph Node Cytopathology.

Pancreatic cystic lesions, frequently detected in abdominal imaging, pose diagnostic challenges due to their varying malignancy potential. This review article focuses on the crucial role of molecular diagnostics in differentiating these lesions, with an emphasis on the significance of KRAS and GNAS mutations identified through endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). The use of next-generation sequencing (NGS) is highlighted for its precision in detecting genetic changes, crucial for accurate diagnosis and guiding management decisions.

Integration of molecular studies into standardized reporting for pancreaticobiliary cytopathology is also discussed, enhancing diagnostic accuracy. The potential of precision oncology, informed by molecular insights, is explored for targeted treatments of pancreatic cystic lesions.

Commercial platforms like PancreaSeq® Genomic Classifier and PancraGEN® are assessed for their effectiveness in analyzing pancreatic cystic fluid, proving beneficial in cases where traditional methods fall short.

In summary, molecular studies are indispensable in evaluating pancreatic cystic lesions, offering a pathway to more personalized treatment and management strategies in patient-centered care.

Serous fluids, encompassing pleural, pericardial, and peritoneal fluids, exhibit a wide spectrum of neoplastic and non-neoplastic conditions. Malignant effusions commonly result from metastasis, particularly from adenocarcinomas, and less frequently from primary malignant mesothelioma. Cytologic assessment of serous effusions remains an invaluable tool, especially with the expanding role of ancillary techniques available to resolve diagnostically challenging cases. The recently introduced International System for Reporting Serous Fluid Cytopathology (TIS) establishes a standardized reporting system with five distinct diagnostic categories: nondiagnostic (ND), negative for malignancy (NFM), atypia of undetermined significance (AUS), suspicious for malignancy (SFM), and malignant (MAL). Understanding the distribution of malignancy in serous fluids by site of origin in effusion cytology is important, especially in patients with an unknown primary. Immunohistochemistry (IHC) combined with clinical and radiologic data plays a crucial role in confirming malignancy, establishing the primary site, determining the stage, predicting prognosis, monitoring recurrence, and influencing medical management. This review aims to provide an overview of TIS reporting system, emphasizing its malignant category. It provides updates on the distribution of malignancies in serous fluids and discusses valuable IHC panels based on differential diagnosis, addressing challenging cases within this context.

The upcoming World Health Organization (WHO) Reporting System in Liver Cytopathology marks the first internationally applicable system for diverse medical infrastructure settings. This system categorizes cases into five groups: Insufficient/Inadequate/Nondiagnostic, Benign, Atypical, Suspicious for Malignancy, and Malignant. Each category is associated with a risk of malignancy (ROM), guiding recommendations for further diagnostic testing to achieve specific diagnoses or refine differential diagnoses and follow-up management. The primary goal is to enhance and standardize cytopathology reporting, improve communication between cytopathologists and clinicians, and ultimately elevate patient care. The online WHO System provides direct access to the WHO Classification for Tumours 5th Edition. This review delves into the latest classification guidelines, addresses terminology standardization, navigates diagnostic complexities, and aligns patient management options with cytopathological interpretations, contributing to an overall enhancement of patient care.

Malignant Brenner tumor (MBT) of the ovary is exceedingly rare, and studies of MBT have been limited to case reports and small case series. MBT shares similar clinical and radiological presentations with other ovarian epithelial malignancies, and the diagnosis of MBT is predominantly based on histopathologic evaluation. Recently, relatively large retrospective studies have advanced understanding of their histogenesis and malignant transformation, as well as on the clinical management of this rare subtype of ovarian carcinoma. In this article, we review the published English literature on MBT, with an emphasis on the histopathologic evaluation, molecular biology, and clinical management of MBT.

The World Health Organization (WHO) has recently introduced an international approach to standardize reporting of pancreaticobiliary cytopathology. The WHO Reporting system for Pancreaticobiliary Cytopathology (WHO system) introduces two distinct categories for non-invasive premalignant lesions of the ductal system, based on cytomorphological grading: “pancreatic neoplasm of low risk/grade” (PaN-low) and “pancreatic neoplasm of high risk/grade” (PaN-high). This reclassification aims to provide a more precise assessment of risks of malignancy (ROM) for different neoplastic categories. The WHO system focuses on the diagnostic categories, their associated ROM, and recommended management per category.

Pancreatic neoplasms comprise various histological types, each displaying distinct background features that can assist in the diagnostic process. Recognizing background features like mucin background, necrotic background, desmoplastic stroma, cancer-associated fibroblasts, and stromal fragments presents notable challenges. Certain background features may overlap across histological types.

In this review, we present a summary of the key updates in the WHO system and highlight diagnostic challenges associated with background features.

The mesenchymal tumors of the pancreas account for approximately 1–2% of all pancreatic neoplasms and they are not commonly encountered in our daily practice. When these rare entities are seen during endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) with rapid onsite evaluation (ROSE) or EUS-guided fine-needle biopsy (FNB) specimens sampled from the pancreas, it is usually difficult to establish a diagnosis solely based on cytohistology due to the significant overlapping cytomorphological features among these neoplasms. Ancillary studies including immunohistochemical stains and molecular testing are critical to reach the correct final diagnosis. Here, we reviewed the pancreatic mesenchymal neoplasms diagnosed with EUS-FNA cytology specimens or EUS-FNB small biopsy specimens. Gastrointestinal stromal tumors (GIST), solitary fibrous tumors (SFT), paraganglioma, perivascular epithelioid cell tumor (PEComa), and Granular cell tumor were discussed in detail each with a representative case from our practice collections. The characteristic cytohistological features and immunostaining markers for each entity are highlighted for differential diagnosis. In summary, cytopathologists need to be vigilant for these rare entities and perform necessary immunostaining to establish an accurate diagnosis.

With the increasing emphasis on early detection of lung carcinoma in clinical practice, the utilization of small biopsies including cytology specimens has become more prevalent and an integral part of the diagnostic process. While holding immense significance for patient care and decision-making, the accurate identification of lung carcinoma from these small biopsies poses challenges. There is a significant overlap in the characteristics among benign, reactive, and malignant processes. This is aggravated by the absence of distinguishing biomarkers. Preserving specimen material for additional cytogenetic and molecular testing has also gained prominence to enable targeted precision medicine.

The focus of our review is directed towards understanding the morphologic attributes and potential diagnostic mimickers associated with the most frequent types of lung carcinoma observed in small biopsies. Additionally, we emphasize the importance of proper immunohistochemical staining practices to preserve tissue for further molecular testing.