Cytopathology: the small specimen subspecialty

Synovial sarcoma: cytopathology of 51 cases highlighting the application of ancillary molecular testing

INTRODUCTION

Among sarcomas, synovial sarcoma (SS) is defined by its unique SS18 cytogenetic translocation. Fine needle aspiration (FNA) biopsy is in a key position to exploit this uniqueness for diagnostic purposes.

MATERIALS AND METHODS

Our cytopathology files were searched for examples of SS with histopathologic verification. FNA biopsy, imprint smears, and core needle biopsy (CNB) were performed using standard techniques.

RESULTS

Fifty-one cases from 49 patients (male/female ratio, 1:1; age range, 12-79 years; mean age, 40 years) met the inclusion criteria. Of the 51 cases, 44 (86%) were FNAs, 6 were cytology imprints, and 1 was pleural fluid. Eleven aspirates had concurrent CNB. All cases had tissue confirmation. The biopsy sites included extremities (n = 24; 47%), trunk (n = 12; 24%), lung (n = 8; 16%), head or neck (n = 6; 12%), and pleural fluid (n = 1; 2%). The aspirates were from primary (n = 36; 71%), metastatic (n = 12; 24%), and recurrent (n = 3; 5%) neoplasms. The cytologic diagnoses were SS (69%), suspicious for SS (12%), malignancy (10%), spindle cell neoplasm (4%), and malignancy other than SS (6%). In general, smears and imprints contained dense cell aggregates and single cells composed of a monotonous population having fusiform, rounded, or ovoid banal nuclei and scant cytoplasm. Poorly differentiated SS showed both large epithelioid cell and small cell cytomorphology. When performed, SS18 immunohistochemical and genetic testing was positive in all 19 FNA and 3 CNB cases.

CONCLUSIONS

When coupled with appropriate ancillary testing, FNA biopsy allows for a specific, accurate diagnosis of SS in most cases.

State-of-the-art cytology of pleural fluid, focusing on the diagnosis of mesothelioma

Mesothelioma has always been a challenging diagnosis to render in body cavity cytology samples. This review is a timely update on pleural fluid cytology and ancillary studies that should be considered in the diagnosis of mesothelial proliferations, specifically mesotheliomas. Information about new diagnostic approaches and ancillary studies in mesothelioma was obtained from the peer-reviewed literature and the authors' experiences. Although the morphological diagnosis of mesothelioma is fraught with numerous challenges given the overlap with other diagnostic entities, there are a variety of immunohistochemical and fluorescence in situ hybridization studies available to help in determining mesothelial origin and in distinguishing malignant proliferations from the more common benign or reactive mesothelial proliferations. Although ancillary studies can be helpful, there are important pitfalls to be aware of when interpreting these cases, and this review highlights some of the challenges that require caution.

To whom the specimen goes: a look at how touch preparations and core needle biopsies are handled in different practices and the effect on fellowship education

INTRODUCTION

Core needle biopsies (CNBs) have proven to be an excellent source of tissue for diagnosis and ancillary testing in the era of personalized medicine, commonly yielding sufficient material for testing via a relatively minimally invasive technique. Thus, there has been an increase in touch preparations (TPs) evaluated with rapid onsite evaluation (ROSE) of these small biopsies either in isolation or with concurrent fine needle aspiration (FNA). This in turn has forced cytopathology practices to make decisions with regard to processing and workflow of CNBs, which affects cytopathology fellowship education substantially.

STUDY DESIGN

The present review is based on a review of recent literature and an evaluation of the authors' personal experiences.

RESULTS AND CONCLUSIONS

Deciding whether CNBs with associated TPs should be assigned to the cytology service, the subspecialty or general surgical pathology service, or a split between cytopathology and surgical pathology, is complicated. The workflow is variable at different institutions depending on multiple factors. Each of these routes has benefits and disadvantages that can affect patient care and laboratory workflow, in addition to having downstream effects on the quality and type of education our pathology trainees receive. Herein, the advantages and disadvantages of the different approaches for CNB triage are discussed, with an emphasis on the impact upon cytopathology fellowship education.

Cytopathology fellowship recruitment: Has the time come to consider a unified approach?

INTRODUCTION

Cytopathology (CYP) fellowship training is a critical component of maintaining a skilled group of cytopathologists. For years, the recruitment process for CYP fellowship programs has remained unchanged, with individual programs outlining their own requirements and timeline, and applicants bearing the cost of travel and dealing with the variable processes outlined by individual programs. However, there has been renewed interest in analyzing the recruitment process for CYP fellowships to look for areas of potential improvement and uniformity.

METHODS

With the goal of gauging the interest of CYP fellowship program directors (PDs) in a more unified approach to recruitment or a formal match process, the ASC Cytopathology Program Directors Committee (CPDC) surveyed PDs via SurveyMonkey and organized special webinars with polling over a 4-year time frame (2017-2021), and examined Qualtrics survey data collected by the American Board of Pathology (ABPath) in 2020.

RESULTS

The response rate for PDs was greatest in a formal survey by the ABPath (66 respondents; 71% of PDs) conducted in 2020, and lower for an ASC survey in 2021 (61 respondents, 66% of PDs) and 2017 (19 respondents; 21% of PDs) and two recent ASC webinars (10 and 26 respondents; 11% and 28% of PDs). Support for a fellowship match process varied from 29% to 77%, respondent uncertainty ranged from 13% to 50%, and a lack of support ranged from 10% to 60%. In aggregate, approximately 56% of respondents would be in favor of a more standardized process. Recently, after hearing about other fellowships experimenting with a standardized process, the interest in a unified approach doubled from approximately 29% to 60%, and the percentage of PDs with uncertainty decreased from 50% to 26%. In the most recent follow up survey, interest reached the highest level of 77% among PDs.

CONCLUSIONS

Herein we present several years of feedback from the CYP fellowship PD community regarding a more standardized approach to CYP fellowship recruitment, culminating in the latest survey with 77% of CYP fellowship PDs expressing interest. Thus, details about what a unified timeframe may look like for CYP fellowships is presented to show how this may improve the recruitment process for the mutual benefit for programs and applicants.

Impact of laboratory work-up of lymphoma guidelines on cytopathology practices

A multi-society expert panel recently published evidence-based guidelines and recommendations for the primary diagnosis and classification of lymphoma, which included a public comment period. The guideline concludes: "primary diagnosis and classification of lymphoma can be achieved with a variety of specimens." The guideline recommends that fine-needle aspiration biopsy (FNAB) cytomorphology not be used without ancillary testing, and that either flow cytometry or immunohistochemical immunophenotyping be performed for any type of specimen. Either excisional or core biopsy should be obtained when there is a high suspicion of lymphoma, and excision is recommended when feasible for Hodgkin lymphoma primary diagnosis. The use of cerebrospinal fluid to diagnose central nervous system lymphoma is discussed. For any patient with initial negative biopsy or fluid specimens and a high suspicion of lymphoma, additional tissue samples should be obtained. Additional molecular testing and good practice statements are summarized in the guideline. Cytopathologists should continue to advocate for judicious use of lymph node FNAB as an excellent triage tool that may require additional tissue biopsy for definitive diagnosis.