High-grade endometrial stromal sarcoma (HGESS) is a rare sarcoma with aggressive biological behavior. Here we report a case of molecularly confirmed ZC3H7B-BCOR HGESS in extrauterine, with morphologic and immunohistochemical findings resembling a gastrointestinal stromal tumor. The patient, a 51-year-old woman, presented with extensive pelvic and abdominal masses. Histologically, the tumor displayed fascicles of spindle cells with myxoid stroma and abundant mitosis. Immunohistochemical staining revealed that the tumor cells were diffusely positive for cluster of differentiation 117 (CD117) and discovered on gastrointestinal stromal tumor 1 (DOG1). Gastrointestinal stromal tumor was initially diagnosed, and DNA sequencing was performed for targeted therapy. Unexpectedly, no mutations in KIT proto-oncogene, receptor tyrosine kinase (CKIT) or platelet-derived growth factor receptor, alpha polypeptide (PDGFRA) were identified, but amplification of murine double minute 2 (MDM2) and cyclin-dependent kinase 4 (CDK4) was found. Further, ZC3H7B-BCOR fusion was detected via RNA sequencing. Additional immunostaining showed that CD10 was diffusely positive, the estrogen receptor was negative, and the progesterone receptor was weakly positive. ZC3H7B-BCOR HGESS was definitively diagnosed. In conclusion, the coexpression of CD117 and DOG1 may present a potential diagnostic pitfall in the evaluation of pelvic/abdominal masses, which should be paid great attention.

Malignant rhabdoid tumor (MRT) is an aggressive malignancy driven by pathogenic variants of SMARCB1/INI1 or, rarely, SMARCA4/BRG1. The heterogeneity of MRT suggests that other genomic alterations might contribute to tumor behavior. This study aimed to evaluate somatic copy number alterations (SCNAs) and mutation landscapes in MRT before and after treatment.

With IRB approval, five patients underwent normal-tumor paired whole exome sequencing. Subsequently, the results were further analyzed using MuTect v1.1 for variant DNA and cn.mops for SCNA.

Our study revealed recurrent SCNAs harboring genes known to be involved in tumorigenesis. These include 2q37.3 gain (4/5, 80%, programmed death 1, TWIST2), 7q32.1 gain (3/5, 60%), 11q12.2 gain (3/5, 60%), 14q32.3 gain (4/5, 80%), 19p13.2 loss (SMARCA4, 4/5, 80%), 21q22.3 gain (3/5, 60%), and 22q11.1 loss (2/5, 40%, involving SMARCB1). Alterations more common in posttreatment MRTs included 11p15.4 gain (3/3, 100%) and 11q12.2 gain (2/3, 67%). No actionable pathogenic variants were observed. PD-1 immunohistochemistry correlated with 2q37.3 gain.

Our study revealed recurrent SCNAs in MRT. Genes within these regions are known to be associated with the tumor immune response and metastasis. This preliminary study demonstrated the potential value of SCNAs in furthering the understanding of this highly malignant tumor.

The World Health Organization Reporting System for Lung Cytopathology is the first international system that was developed to standardize the reporting of lung cytopathology specimens across all settings of cytopathology practice. The system is composed of five diagnostic categories, which apply to all lung cytopathology specimen types. Each category contains cytomorphologic criteria, an estimated risk of malignancy, and clinical management recommendations. International uniformity in the reporting of lung cytopathology will refine the communication between cytopathologists and clinicians and ultimately improve patient care. Furthermore, standardizing the cytomorphologic criteria for each lesion will improve reproducibility among cytopathologists and highlight areas in lung cytopathology that require further research. The system also provides best practice recommendations for the selection of ancillary tests to aid in the diagnosis of each lesion, or group of lesions, keeping in mind that resources will vary across different practice settings. The goal of this review is to summarize the cytomorphologic criteria, potential diagnostic pitfalls, ancillary testing, estimated risk of malignancy, and clinical management recommendations for each diagnostic category.

Coagulation testing is essential for the diagnosis and management of a variety of hemophilia, thrombophilia, and complicated coagulopathies. This is often used prior to surgery, or as a follow-up investigation for patients being scrutinized for bleeding diathesis, or to monitor the anticoagulant therapy. When the results are abnormal, a mixing study is often the initial reflexive test that can provide valuable information to conclude the assessment, or help guide further investigations. If the mixing “corrects” the test results, a factor deficiency would be suspected. Otherwise, the presence of an inhibitor would be more likely. However, defining “correction” remains difficult and controversial. There are several available methods to determine whether a result is corrected. Each method has its own advantages and limitations. It is noteworthy that although a complete correction can be interpreted as factor deficiency, a partial or incomplete correction does not rule out the coexistence of factor deficiency and the presence of a coagulation inhibitor. Hence, caution should be taken in interpreting mixing study results for patients who are taking direct-acting oral anticoagulants. Ideally, mixing study results are interpreted in correlation with the patient’s clinical history, including bleeding or thrombosis history, and the use of anticoagulants.

The Bethesda System for Reporting Thyroid Cytopathology is the first reporting system established in non-gynecologic cytopathology after the Bethesda System for Reporting Cervical Cytopathology. It adopts the same concept of providing a uniform reporting system for all pathologists and clinicians to follow in thyroid cytology. The reporting system is composed of six diagnostic categories. There are defined diagnostic criteria, estimated risk of malignancy, and management recommendations for each category. The reporting system has undergone two revisions upon the emergence of a new entity, updated terminology in histology, and development and refinement of molecular testing. The third edition is soon to be published in 2023. This review will provide an updated summary of the reporting system. Potential diagnostic pitfalls and molecular testing are also discussed.

The Paris System for Reporting Urinary Cytology (TPS 1.0, published in 2016) is the first standardized, evidence-based reporting system established as an international reporting system for urine specimens after the International Congress of Cytology in Paris. Its primary purpose is to reduce the rate of unnecessary indeterminate diagnoses, but maintain the excellent performance of urine cytology, in detecting high-grade urothelial carcinoma. The reporting system comprises of six diagnostic categories, as well as each category’s diagnostic criteria, estimated risk of malignancy, and management recommendations. After six years, TPS 2.0 was applied in 2022 upon the unfolding of new data. TPS 2.0 clarifies the diagnosis categories, and updates the risk of malignancy in each category and developments of molecular tests. This review provides an updated summary of TPS 2.0. Some diagnostic pitfalls and molecular tests were also discussed.