A Proposal for the Performance, Classification, and Reporting of Lymph Node Fine-Needle Aspiration Cytopathology: The Sydney System

Endobronchial ultrasound-guided transbronchial fine needle aspiration of mediastinal lymphadenopathy: Diagnostic performance and clinical implications of the World Health Organization reporting system

INTRODUCTION

Lymph node fine-needle aspiration cytology (LN-FNAC) is a common, rapid, minimally invasive and cost-effective diagnostic method. For mediastinal lymph nodes, endobronchial ultrasound (EBUS) guided LN-FNAC is a first-line investigation and has an indispensable role in the diagnosis and staging of patients with suspected lung cancer. Recently, a new WHO system has been proposed for classification of LN-FNAC heralding five different diagnostic categories; insufficient, benign, atypical, suspicious for malignancy and malignant. The aim of this study was to evaluate the diagnostic accuracy and risk of malignancy (ROM) of these categories in EBUS-guided LN-FNAC from mediastinal lymph nodes.

METHOD

We evaluated 2110 consecutive mediastinal lymph nodes during this one-year retrospective study. Corresponding radiological images and histologic material were used as ground truth to calculate accuracy, sensitivity, specificity and ROM.

RESULTS

The WHO system showed an overall accuracy of 93.7% with a sensitivity of 83.0% and a specificity of 97.5%. The positive predictive value was 92.3% and the negative predictive value 94.2%. The overall ROM for each category in the WHO classification system was 12.8% for the inadequate, 2.4% for the benign, 47.4% for the atypical, 81.0% for the suspicious for malignancy and 93.6% for the malignant category.

CONCLUSION

The results of the present study indicate that the new WHO system entails a high diagnostic accuracy regarding EBUS-guided LN-FNAC assessment of mediastinal lymph nodes and supports its integration into clinical practice. Application of the WHO system standardizes risk assessment thus facilitating communication between cytopathologists and clinicians and minimizes the need for histopathological analysis.

Parotid squamous cell carcinoma metastases: Application of human papillomavirus-DNA test on liquid-based cytology to recognize oropharyngeal origin of the neoplasm

Malignancies of the parotid gland are relatively uncommon and in most cases are primary neoplasms; intraparotid metastases are rare. Oral and oropharyngeal squamous cell carcinoma (O- and OP-SCC) can potentially metastasize to the parotid gland or intraparotid lymph nodes. Fine-needle aspiration cytology (FNAC) serves as the initial diagnostic approach for this purpose. HPV status in FNAC specimens is relevant and can guide the diagnostic workup, indicating a potential oropharyngeal origin of the primary tumor. A small series of occult SCC metastases is presented below, in which HPV-DNA testing of FNAC specimens helped identify primary neoplasms located in the oropharynx. US-guided FNAC of parotid nodules was conducted by an experienced interventional cytopathologist in three cases. Each patient underwent assessment of direct smears, cell blocks, and liquid-based samples for HPV testing. The morphological and immunocytochemical features of SCC were documented, and real-time PCR was employed for the detection and genotyping of HPV. The role of HPV testing on FNAC specimens in pinpointing the primary neoplasms in the oropharynx is highlighted. Consequently, FNAC samples emerge as valuable diagnostic and prognostic tools in this context, providing essential insights for patient management.

The Sydney system for lymph node FNA biopsy cytopathology: A detailed analysis of recent publications and meta-analysis and a proposal for the components of an ideal prospective study of a cytopathology reporting system

BACKGROUND

The Sydney system for fine-needle aspiration biopsy of lymph nodes has five categories, stressing the role of correlation of cytopathology with clinical, ultrasound, and ancillary findings to achieve diagnosis. The five categories constitute a hierarchical system with increasing risk of malignancy from benign to atypical, suspicious, and malignant categories, which informs recommendations for further workup to achieve a final diagnosis as possible. This article analyzes 10 publications using the Sydney system and a meta-analysis of nine of these studies. The primary goal of the analysis is to ascertain the causes of the large ranges in risk of malignancy for the "atypical" and "inadequate" compared to "benign," "suspicious," and "malignant" categories, which were comparable to well-established reporting systems. Research protocols are proposed to improve future studies.

METHODS

PubMed literature search from January 2021 to December 2023 identified studies evaluating performance of the Sydney system.

RESULTS

Ten studies showed heterogeneity with clinical setting, study design, ultrasound use and rapid on-site evaluation, operator, cutoff points for "positive" cases, with inherent partial verification biases, resulting in a wide range of risk of malignancy, specificity, and sensitivity values.

CONCLUSION

Analysis shows the large range is due to heterogeneity of the studies, which suffer from biases and variable statistical analysis that are ultimately included in any meta-analysis, detracting from the usefulness of the risk of malignancy derived by the meta-analysis. Components for ideal analyses of reporting systems are presented.

Peripheral lymphadenopathy of unknown origin in adults: a diagnostic approach emphasizing the malignancy hypothesis

The term lymphadenopathy refers to an abnormality in size, consistency or morphological aspect of one or several lymph nodes. Although lymphadenopathies are commonly observed in everyday clinical practice, the difficulty of differentiating benign and malignant disease may delay therapeutic approaches. The present review aims to update diagnostic algorithms in different clinical situations based on the currently available literature. A literature review was performed to assess current knowledge of and to update the diagnostic approach. A short clinical vignette was used as an example of a typical clinical presentation. This case of metastatic lymphadenopathy with incomplete patient history demonstrates how misleading such lymphadenopathy may be, leading to a delayed diagnosis and even a fatal outcome. Any lymphadenopathy persisting for more than 2 weeks should be considered suspicious and deserves further investigation. Precise clinical examination, meticulous history-taking and a search for associated symptomatology are still cornerstones for diagnosing the origin of the condition. The next diagnostic step depends on the anatomical region and the specific patient's situation. Imaging starts with ultrasound, while computed tomography (CT) and magnetic resonance imaging (MRI) allow assessment of the surrounding structures. If the diagnosis remains uncertain, tissue sampling and histological analyses should be performed. Except for head and neck loco-regional lymphadenopathy, there are no methodical guidelines for persistent lymphadenopathy. The present review clarifies several confusing and complex situations. The accuracy of fine needle aspiration cytology could be increased by using core needle biopsy with immunocytologic and flow cytometric methods. Notably, except in the head and neck area, open biopsy remains the best option when lymphoma is suspected or when inconclusive results of previous fine needle aspiration cytology or core needle biopsy are obtained. The incidence of malignant lymphadenopathy varies with its location and the various diagnostic strategies. In metastatic lymphadenopathy of unknown primary origin, European Society for Medical Oncology (ESMO) guidelines and modern methods like next-generation sequencing (NGS) may help to manage such complex cases.

Assessment of Ki-67 Proliferative Index in Cytological Samples of Nodal B-Cell Lymphomas

BACKGROUND

The Ki-67 proliferative index (PI) is part of the diagnosis of nodal B-cell lymphoma (nBCL), but its determination in cytological samples is not standardized. We aimed to establish an approach for the accurate determination of the Ki-67 PI in cytological slides to differentiate between indolent and aggressive nBCLs.

METHODS

Patients diagnosed with nBCL by fine-needle aspiration biopsy and subsequent excision biopsy were included. Cell suspensions were prepared from biopsy samples for CD3/Ki-67 double immunocytochemical staining and flow-cytometric verification of lymphoma B-cell counts. The Ki-67 PI was assessed by manual counting and eyeballing in cytology and eyeballing in histology. The cut-off values for the differentiation between aggressive and indolent lymphomas were determined for each method.

RESULTS

A strong correlation between manual and flow-cytometric counting of lymphoma B cells was confirmed (interclass correlation coefficient (IC coef.) = 0.78). The correlation of the Ki-67 PI determined in cytological and histological slides was also strong (IC coef. > 0.80). Histologically, 55 cases were classified as indolent and 31 as aggressive nBCLs. KI-67 PI cut-off values of 28.5%, 27.5%, and 35.5% were established for manual counting and eyeballing in cytology and eyeballing in histology, respectively, with high sensitivity and specificity.

CONCLUSIONS

The Ki-67 PI, assessed by manual counting and eyeballing in cytological samples, accurately differentiates between indolent and aggressive nBCLs.

Uses and limitations of small-volume biopsies for the diagnosis of lymphoma

Although surgical biopsy remains the gold standard for the diagnosis of lymphoma, small-volume biopsies including fine-needle aspiration and core needle biopsy are increasingly being used as a first line diagnostic tool. Small-volume biopsies are safe, rapid and cost effective; however, diagnostic utility varies by lymphoma subtype. It is important for pathologists and clinicians to recognize both the strengths and limitations of such biopsies.

Diagnostic Accuracy of Fine-Needle Aspiration Cytology in Cervical Lymphadenopathies at a Tertiary Care Center in the Kingdom of Bahrain

Introduction  Fine-needle aspiration cytology (FNAC) has become widely used as a first-line diagnostic tool in the evaluation of cervical lymphadenopathies (LADs). However, there are conflicting reports regarding its accuracy in differentiating between malignant and benign pathologies. In this study, we aim to determine the reliability of FNAC in distinguishing between benign and malignant pathologies causing cervical LAD. Methods This is a cross-sectional study reviewing the electronic medical records of all patients who underwent both FNAC and excisional biopsy of cervical LADs between January 2016 and December 2023 at a tertiary care center in the Kingdom of Bahrain. A comparison was conducted between the cytopathological results obtained by FNAC and the histopathological results obtained by excisional biopsy to determine the diagnostic accuracy of FNAC. Results In the study period, 83 patient records were reviewed and included in the data analysis. Fine-needle aspiration cytology yielded a sensitivity of 89.3%, a specificity of 55.6%, a positive predictive value (PPV) of 72.4%, a negative predictive value (NPV) of 80.0%, and an overall accuracy of 74.7% in diagnosing cervical LADs. Conclusion Despite FNAC being accessible, convenient, and cost-effective, it has certain limitations that can restrict its accuracy in diagnosing lymphomas. We recommend further studies to research these limitations and the possible tools, such as ancillary testing, that may be useful in overcoming them.

Accuracy of ultrasound-guided fine-needle aspiration for small cervical lymph nodes: A retrospective review of 505 cases

Purpose

The overall diagnostic value of fine-needle aspiration (FNA) is not as excellent as that of core needle biopsy (CNB). Limited research has investigated small cervical lymph nodes inaccessible to ultrasound-guided CNB due to technical challenges associated with their small size. Therefore, this study aimed to evaluate the accuracy of ultrasound-guided FNA in determining the etiology of small cervical lymph nodes.

Methods

A retrospective analysis was conducted on patients who underwent FNA between May 2018 and May 2021 at our hospital. Cytological, histopathological, and clinical follow-up data were analyzed. The diagnostic yield of FNA was assessed based on sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy calculations.

Results

This study included 505 patients, each with a small cervical lymph node under evaluation (total number of lymph nodes: 505). The average maximal diameter of the lymph nodes was 14.6 ± 6.2 mm. According to the Sydney system, the cytology results were as follows: Category I in 26 lymph nodes (5.1 %); Category II in 269 (53.3 %); Category III in 35 (6.9 %); Category IV in 17 (3.4 %); and Category V in 158 (31.3 %). We identified 212 malignant cases (203 metastases and 9 lymphomas) and 293 benign lymph nodes. FNA achieved high sensitivity (88.8 %), specificity (99.6 %), PPV (99.4 %), NPV (91.8 %), and overall accuracy (94.8 %) in determining the etiology of small cervical lymph nodes.

Conclusion

FNA cytology is suitable for small lesions inaccessible by CNB and provides a diagnostic basis for implementing clinically appropriate treatment measures.

Analysis of flow cytometry data from ultrasound-guided lymph node biopsies with two types of needles

BACKGROUND

In this study, we combined two techniques, ultrasound-guided needle biopsy and flow cytometry (FCM), to explore their value in patients with enlarged lymph nodes.

METHODS

We compared the results of 198 needle biopsies on FCM and pathology. Forty-two were done by (fine needle aspiration, FNA), and the remaining 156 with (core needle biopsy, CNB), in 36 of 156 patients, a FNA was performed in the same lymph node after completion of the CNB. Except for five types of pathological entities, the rest were differentiated only detected or undetected tumours as the outcome distinction.

RESULTS

Among the 198 needle biopsies, 13 were inadequate specimens, while the remaining 185 had pathological findings, including 47 benign and 138 neoplastic findings. Thirty-six patients underwent puncture with both FNA and CNB, both needles produced identical results by FCM, but more cells were obtained by FNA. Among the pathologically positive results, there were 23 missed diagnoses in FCM, in contrast, evidence of tumours was observed in the FCM images of 15 needle biopsies that reported benign or findings that were inconsistent with pathology, and the final diagnosis was consistent with the FCM in 10 cases. FCM detected haematolymphoid tumours with a sensitivity of 87.8% and a specificity of 91.9%.

CONCLUSION

The combination of FCM and ultrasound-guided lymph node needle biopsy can quickly provide guidance for clinical decision-making. We recommend that all lymph node needle biopsies be sent for FCM, the specimen can be obtained by the last puncture with FNA.

Upcoming World Health Organization system for reporting lymph node cytopathology-A preliminary outline

Purple book for WHO reporting for lymph node cytopathology - 2023. Lymph node cytopathology reporting system may use standardized nomenclature and usage of the terminologies harmonizing with the WHO Blue Book on hematolymphoid tumors.

Bilateral intra-lymph node Warthin's tumor as a potential diagnostic pitfall mimicking metastatic carcinoma

Warthin's tumor (WT) is a benign and frequent salivary gland tumor primarily affecting the parotid gland. In some cases, this tumor can involve the extra parotid region and affect cervical lymph nodes. Fine-needle aspiration can be the first step in the diagnostic approach to lymphadenopathy; however, specimens from intra-nodal WT can present a potential pitfall, leading to a misdiagnosis of metastasis. Here, we report an unusual case of a patient with bilateral WT in parotid lymph nodes misdiagnosed as metastases. In addition, we highlight the cytopathological aspects of WT to alert cytopathologists about this challenging diagnosis.

Immunocytochemistry on frozen-embedded cell block for the diagnosis of hematolymphoid cytology specimen: a straightforward alternative to the conventional cell block

Agarose-based cell block (CB) technique can be modified to be combined with the frozen section technique for the preparation of a high-quality frozen-embedded CB (F-CB) from an effusion or fine-needle aspiration (FNA) cytology sample. This combined technique can be effectively used for the immunocharacterization of the hematolymphoid cells on F-CB. To demonstrate the applicability of performing diagnostic ICC on F-CB, we have analyzed the immunophenotype of the hematolymphoid cells in a series of eight cases of effusions and eight cases of FNA cytology specimens by using CB-ICC on sections cut from frozen-embedded CBs. The SurePathTM residue or cytologic material scraped off from the FNA cytology smear that was diagnostic for or suspicious of hematolymphoid malignancy was pelleted and pre-embedded in agarose. Half of the agarose-embedded pellet was frozen-embedded in OCT compound for the preparation of F-CB, while the other half was processed for the preparation of paraffin-embedded CB. Sections cut from the F-CB and P-CB were used for CB-ICC. Panels of ICC on the F-CBs could enable the immunocytochemical differential diagnosis of large cell hematologic malignancies that encompass anaplastic large cell lymphoma and other forms of large-cell hematolymphoid malignancies such as large B-cell lymphomas, anaplastic plasma cell myeloma, myeloid sarcoma, and T-lymphoblastic lymphoma. It also appeared that the small B-cell lymphomas in the effusions or FNAs could be differentially diagnosed with the aid of CB-ICC on the F-CB. A modified agarose-based CB technique can be combined with the frozen-embedded CB method for the preparation of F-CB that can be directly used for the immunocytochemical differential diagnosis of hematolymphoid cytology samples.

Resident training in interventional pathology: Ultrasound-guided fine-needle aspiration and rapid on site evaluation-5 years of teaching experience in a single university hospital

INTRODUCTION

Despite the established role of the interventional pathologist, their diagnostic performance is difficult to establish. At least in Spain training of pathology residents in ultrasound-guided interventional procedures for specimen collection is limited or absent in most institutions. We present our teaching experience in the instruction of ultrasound-guided fine-needle aspiration (FNA) to pathology residents in a tertiary-level hospital.

MATERIALS AND METHODS

The training of pathology residents who rotated through the interventional unit of the pathology department and the application of ultrasound-guided FNA and rapid on-site evaluation (U-ROSE) was documented over 5 years. The training period was broken down into learning phases and included the number of ultrasound-guided FNA performed, anatomical location, and their diagnostic performance, among other aspects.

RESULTS

Nineteen (19) pathology residents were trained in U-ROSE, and performed a total of 4003 procedures, with a mean of 211 per resident. In 53% of cases only one pass was required for an adequated sample. The specimen was diagnostic in more than 97% of cases. The most frequently sampled anatomical sites were the thyroid gland (n = 2347), followed by lymph node (n = 667), soft tissues (n = 663) and salivary glands (n = 322).

CONCLUSION

The results support the training programme followed by pathology residents in learning U-ROSE, which is essential to lay the foundations for the future interventional pathologist.

Review of the impact of the International System for Serous Fluid Cytopathology

The International System for Reporting Serous Fluid Cytology (TIS) has been proposed by an expert working team composed of the International Academy of Cytology and the American Society of Cytopathology, following an international survey. Since its introduction, the TIS has gained worldwide acceptance, and this review aims to assess its global impact. A literature search revealed 25 studies which have presented data on the impact of the TIS. Most of them provide data, including risk of malignancy (ROM) for each diagnostic category, separately for pleural, peritoneal and pericardial effusions, while a few do not separate them. A few studies focus on specific diagnoses like mesothelioma on specific types of fluids or more specific issues like the optimal fluid volume for cytology or interobserver variability. A synopsis of the data from the literature search is presented in four tables. The ROM assessment is discussed, as well as interobserver variability and the use of ancillary diagnostic immunochemistry. In conclusion, our review of the published data suggests that the TIS is a valid classification scheme that has been widely accepted by pathologists globally, is highly reproducible and makes a valuable contribution to clinical therapeutic management.

Combined fine needle aspiration cytology and core needle biopsy in the same setting: A two-years' experience

INTRODUCTION

Fine needle aspiration cytology (FNAC) combined with rapid on-site evaluation (ROSE) and ancillary techniques is an accurate diagnostic tool for many pathologies. However, in some cases, it may not be sufficient for actionable diagnoses or molecular testing, especially for cases that require large immunohistochemical panels or cases in which histological features are mandatory for the diagnosis. Core needle biopsy (CNB), on the contrary, provides samples that are suitable for histological features and sufficient for all ancillary studies. However, CNB is often performed by radiologists or clinicians without the direct participation of cytopathologists, which can lead to missed or delayed diagnoses. This study reports on the experience of combining FNAC and CNB performed in one setting by cytopathologists. The aim was to evaluate the impact of CNB on FNAC and the diagnostic efficiency of the combined procedures.

MATERIALS AND METHODS

One hundred forty-two FNAC and CNB procedures performed in the same setting over a period of 2 years were analysed. The FNAC diagnoses were compared and integrated with the subsequent CNB diagnoses. The impact of CNB was categorized as follows: non-contributory, in cases of inadequate samples; confirmed, when the CNB and FNAC diagnoses were the same; improved, when the CNB diagnosis was consistent with the FNAC diagnosis and further specified the corresponding entity; allowed, when CNB produced a diagnosis that could not be reached by FNAC; changed, when the CNB changed the previous FNAC diagnosis.

RESULTS

CNB confirmed the FNAC diagnosis in 40.1% of cases (n = 57/142). CNB improved the FNAC diagnosis in 47.2% of cases (n = 67/142). CNB allowed a diagnosis that could not be performed on FNAC in 2.1% of cases (n = 3/142). CNB changed a previous FNAC diagnosis in 2.1% of cases (n = 3/142). CNB was non-contributory in 8.4% of cases (n = 12/142). CNB produced a positive impact on the whole diagnostic procedure in 51.4% of total cases (n = 73/142). The combined FNAC and CNB resulted in actionable diagnoses in 91.5% of all cases (n = 130/142). A complete molecular assessment was successfully performed in 14.7% of cases (n = 21/142) utilizing either FNAC or CNB material.

CONCLUSIONS

The combined use of FNAC and CNB in one setting improves the diagnostic accuracy of both procedures. This approach exploits the advantages of each procedure, enhancing the accuracy of the final diagnosis.

Pitfalls in Lymph Node Fine Needle Aspiration Cytology

BACKGROUND

Fine needle aspiration cytology (FNAC) is an accurate, minimally invasive, and cost-effective biopsy method for enlarged lymph nodes. While the role of lymph node FNAC in the diagnosis of infectious or reactive conditions and metastatic malignancy is unquestioned, differing views still exist on its role in the diagnosis of lymphoma. Nevertheless, regardless of the practice setting, pitfalls and potential for error exist, and it is incumbent upon the pathologist to be aware of these pitfalls, as this is the first line of defence against errors.

SUMMARY

This discussion will focus on potential interpretational errors, specifically highlighting scenarios leading to false-negative and false-positive diagnosis and errors in tumour classification, with an emphasis on cytomorphology. Potential entities that may fly below the radar of the pathologist - so-called off-radar entities - are also discussed, as a reminder to consider broad differentials in cases with unusual morphologic features. Some reasons for false-negative diagnoses include low-grade lymphomas that mimic a mixed, polymorphous reactive lymphoid population or aspirates with a paucity of lesional cells, through either sampling error or the intrinsic nature of the entity, e.g., nodular lymphocyte predominant Hodgkin lymphoma. Some of the potential causes of false-positive diagnoses that are discussed include viral-associated lymphadenopathy, Kikuchi-Fujimoto lymphadenitis, or benign adnexal lesions mimicking metastatic malignancy. Errors in tumour classification covered include metastatic carcinoma, sarcoma, melanoma, and lymphoma mimicking each other, and Hodgkin lymphoma and its mimics. Finally, less common entities such as follicular dendritic cell sarcoma and others are briefly mentioned, to remind us of conditions that may slip under our diagnostic radar.

KEY MESSAGES

A systematic review of diagnostic pitfalls and traps is elucidated here, with some tips to avoid these traps. The triple approach to the diagnostic workup is emphasised, which includes rigorous clinicopathologic correlation, attention to cytomorphology, and judicious application of ancillary tests.

The rationale for the development and publication of the World Health Organization reporting systems for cytopathology and a brief overview of the first editions of the lung and pancreaticobiliary systems

The International Academy of Cytology has joined with the International Agency for Research on Cancer and the World Health Organization (WHO) to develop international systems for reporting the cytopathology of lung, pancreas and biliary tract, lymph nodes, soft tissue, liver, breast, and kidney and adrenal gland. The WHO recently published the reporting systems for lung and pancreaticobiliary cytopathology. The objectives of this collaboration are to standardize the reporting of cytopathology; improve the quality of reporting by establishing the key diagnostic cytopathological features of entities and neoplasms; provide detailed best-practice guidelines in sampling techniques, specimen handling and processing, and the use of ancillary techniques; and facilitate communication between cytopathologists and clinicians to improve patient care. Each WHO system has defined specific categories and terminology for reporting cytopathology, and each category has an estimated risk of malignancy as far as the current literature allows and a suggested diagnostic management algorithm to assist clinicians. The WHO systems recognize that local medical and pathology infrastructure will vary, particularly in low-income and middle-income countries, and the WHO systems and their diagnostic management recommendations have been developed to allow them to be applied worldwide in all resource settings. The process of the selection of editors and authors and the writing and editing responsibilities has used the same model as that used for the fifth edition WHO Classification of Tumours, to which the WHO cytopathology systems are directly linked. This review provides the rationale and history of this joint International Academy of Cytology, International Agency for Research on Cancer, and WHO cytopathology project and a brief overview of the WHO reporting systems for lung and pancreaticobiliary cytopathology.

Challenges and opportunities in lymph node FNA: Insights from the DELYCYUS study

The DELYCYUS study represents a significant step forward in the field of lymph node cytology, providing evidence that digital cytopathology, when applied using the Sydney system, yields reliable and reproducible results.

Digital Examination of LYmph node CYtopathology Using the Sydney system (DELYCYUS): An international, multi-institutional study

BACKGROUND

After a series of standardized reporting systems in cytopathology, the Sydney system was recently introduced to address the need for reproducibility and standardization in lymph node cytopathology. Since then, the risk of malignancy for the categories of the Sydney system has been explored by several studies, but no studies have yet examined the interobserver reproducibility of the Sydney system.

METHODS

The authors assessed interobserver reproducibility of the Sydney system on 85 lymph node fine-needle aspiration cytology cases reviewed by 15 cytopathologists from 12 institutions in eight different countries, resulting in 1275 diagnoses. In total, 186 slides stained with Diff-Quik, Papanicolaou, and immunocytochemistry were scanned. A subset of the cases included clinical data and results from ultrasound examinations, flow cytometry immunophenotyping, and fluorescence in situ hybridization analysis. The study participants assessed the cases digitally using whole-slide images.

RESULTS

Overall, the authors observed an almost perfect agreement of cytopathologists with the ground truth (median weighted Cohen κ = 0.887; interquartile range, κ = 0.210) and moderate overall interobserver concordance (Fleiss κ = 0.476). There was substantial agreement for the inadequate and malignant categories (κ = 0.794 and κ = 0.729, respectively), moderate agreement for the benign category (κ = 0.490), and very slight agreement for the suspicious (κ = 0.104) and atypical (κ = 0.075) categories.

CONCLUSIONS

The Sydney system for reporting lymph node cytopathology shows adequate interobserver concordance. Digital microscopy is an adequate means to assess lymph node cytopathology specimens.

COVID-19 post-vaccination lymphadenopathy: A review of the use of fine needle aspiration cytology

COVID-19 vaccine-associated clinical lymphadenopathy (C19-LAP) and subclinical lymphadenopathy (SLDI), which are mainly detected by 18F-FDG PET-CT, have been observed after the introduction of RNA-based vaccines during the pandemic. Lymph node (LN) fine needle aspiration cytology (FNAC) has been used to diagnose single cases or small series of SLDI and C19-LAP. In this review, clinical and LN-FNAC features of SLDI and C19-LAP are reported and compared to non-Covid (NC)-LAP. A search for studies on C19-LAP and SLDI histopathology and cytopathology was performed on PubMed and Google Scholar, on 11 January 2023. Reports on LN-FNAC of C19-LAP were retrieved. A total of 14 reports, plus one unpublished case of C19-LAP observed in our institution, diagnosed by LN-FNAC were included in a pooled analysis and compared to the corresponding histopathological reports. In total, 26 cases were included in this review, with a mean age of 50.5 years. Twenty-one lymphadenopathies assessed by LN-FNAC were diagnosed as benign, and three cases as atypical lymphoid hyperplasia; the latter were subsequently confirmed as benign (one by repetition of LN-FNAC, two by histological control). One case of mediastinal lymphadenopathy in a patient suffering from melanoma was reported as reactive granulomatous inflammation, while one unsuspected case was diagnosed as metastasis from melanoma. In all cases, the cytological diagnoses were confirmed by follow-up or excisional biopsy. The high diagnostic value of LN-FNAC in excluding malignant processes was extremely useful in this context and may be particularly valuable when CNB or histological excisions are difficult to perform, as was the case during Covid lockdowns.

Fine-Needle Aspiration of Sarcomas Metastatic to Lymph Nodes: A Cytomorphologic Study over a 10-Year Period

INTRODUCTION

Metastasis of sarcomas to lymph nodes is an uncommon event in its natural history. We aimed to present our experience with fine-needle aspiration (FNA) of metastatic sarcomas to lymph nodes over a 10-year period.

MATERIAL AND METHODS

The cytopathology archives were searched for FNA of lymph nodes involved by metastatic sarcomas. Available clinicopathologic data were recorded. All slides were retrieved and reviewed.

RESULTS

Thirty-three lymph nodes, from 30 patients, with metastatic soft tissue sarcomas were identified. The lymph node metastases occurred in 16 males and 14 females (median age, 56 years). The size of the lymph nodes ranged from 1.2 to 7.5 cm (median size, 2.9 cm). The inguinal lymph nodes were the most commonly involved nodes, followed by thoracic and cervical neck nodes. The most common metastatic soft tissue sarcoma encountered was Kaposi sarcoma (n = 7, 23.3%), followed by angiosarcoma (n = 6, 20%) and rhabdomyosarcoma (n = 6, 20%). The most common site of primary soft tissue sarcoma was the head and neck (n = 8, 26.6%), followed by lower extremity (n = 7, 23.3%). The initial diagnosis of sarcoma was established in 6 cases. Seventen patients had metachronous involvement of lymph nodes, while the remaining patients had synchronous involvement. Seventen patients died of disease, and the survival after lymph node metastasis ranged from 1 to 43 months.

CONCLUSION

FNA is an accurate and effective method in the diagnosis of metastatic sarcoma to lymph nodes. Knowledge of clinical findings and primary tumor diagnosis along with careful assessment of the cytomorphology is extremely helpful for an accurate diagnosis of metastases.

A stepwise approach to fine needle aspiration cytology of lymph nodes

The cytological diagnosis of lymph node lesions is extremely challenging because of the diverse diseases that cause lymph node enlargement, including both benign and malignant or metastatic lymphoid lesions. Furthermore, the cytological findings of different lesions often resemble one another. A stepwise diagnostic approach is essential for a comprehensive diagnosis that combines: clinical findings, including age, sex, site, multiplicity, and ultrasonography findings; low-power reactive, metastatic, and lymphoma patterns; high-power population patterns, including two populations of continuous range, small monotonous pattern and large monotonous pattern; and disease-specific diagnostic clues including granulomas and lymphoglandular granules. It is also important to remember the histological features of each diagnostic category that are common in lymph node cytology and to compare them with cytological findings. It is also essential to identify a few categories of diagnostic pitfalls that often resemble lymphomas and easily lead to misdiagnosis, particularly in malignant small round cell tumors, poorly differentiated squamous cell carcinomas, and nasopharyngeal undifferentiated carcinoma. Herein, we review a stepwise approach for fine needle aspiration cytology of lymphoid diseases and suggest a diagnostic algorithm that uses this approach and the Sydney classification system.

An economic evaluation of fine-needle cytology as the primary diagnostic tool in the diagnosis of lymphadenopathy

Fine-needle aspiration cytology (FNAC) is commonly used to obtain a pre-surgical pathological diagnosis in many organs, but its cost-effectiveness in lymphadenopathy has not been studied yet. We calculated the cost and diagnostic accuracy of a diagnostic algorithm that uses FNAC as a first-line procedure and compared it to a purely surgical approach in 545 consecutive lymphadenopathies. In 74% of the cases, FNAC alone can obtain a sufficiently detailed diagnosis, avoiding the surgical biopsy. In doing so, the average cost of diagnosis is cut to less than one-third, the patient avoids an invasive procedure and the diagnosis is reached earlier. In conclusion, the systematic use of lymph node-FNAC in the initial assessment of lymphadenopathy is clinically and economically advantageous as it avoids surgical biopsies in cases where cytology can suffice.

Utility of the Proposed Sydney System for Classification of Fine-Needle Aspiration Cytopathology of Lymph Node: A Retrospective Study at a Tertiary Care Center

INTRODUCTION

Fine-needle aspiration cytology (FNAC) is an established first-line technique for the evaluation of lymphadenopathy and, with the help of ancillary testing, can in many instances obviate the need for an open biopsy. The Sydney system was recently proposed to provide consensus guidelines for the performance, classification, and reporting of lymph node FNAC. The present study was undertaken to evaluate its utility and study the impact of rapid on-site evaluation (ROSE).

MATERIAL AND METHODS

A retrospective analysis in which 1,500 lymph node FNACs was reviewed and assigned a diagnostic category from the Sydney system. Cyto-histopathological correlation and adequacy parameters were evaluated.

OBSERVATION AND RESULTS

The cervical group of lymph nodes was the commonest group aspirated (89.7%). A total of 1,205/1,500 (80.3%) cases were category II (benign), and necrotizing granulomatous lymphadenitis was the most common pathology. The 750 cases with ROSE were subclassified as follows: 15 category I (inadequate), 629 category II (benign), 2 category III (atypia of undetermined significance), 9 category IV (suspicious for malignancy), and 95 category V (malignant). Among 750 cases without ROSE, 75 cases were in category I, 576 in category II, 3 in category III, 6 in category IV, and 90 in category V. Category I was thus significantly lower in the ROSE group compared to the non-ROSE group. Overall, the risk of malignancy was L1-0%, L2-0.20%, L3-100%, L4-92.3%, and L5-100%. Accuracy parameters revealed a sensitivity of 97.7%, specificity of 100%, PPV of 100%, NPV of 99.10%, and diagnostic accuracy of 99.54%.

DISCUSSION AND CONCLUSION

FNAC can be used as the 1st line of treatment for lymph node pathology. ROSE can be used as an add-on to FNAC for reducing unsatisfactory rates and help triage material for ancillary testing whenever possible. The Sydney system should be implemented for achieving uniformity and reproducibility.

Salivary gland fine-needle aspiration biopsy: quality assurance results from a tertiary cancer center

INTRODUCTION

Fine-needle aspiration biopsy (FNAB) plays a critical role in the management of patients with salivary gland lesions. A specific diagnosis can be difficult due to the wide range of lesions with overlapping morphologic features, potentially leading to interpretation errors. We analyzed the cytologic-histologic discrepancies identified in the quality assurance program of a major cancer center in cases of salivary gland FNAB and performed a root cause analysis.

MATERIALS AND METHODS

Salivary gland FNAB specimens performed during a 12-year period at a major tertiary cancer center were reviewed. The inclusion criteria for this study included FNAB cases of salivary glands with subsequent histologic or flow cytometry follow up. The cytologic diagnoses for these cases were recategorized according to the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) based on the original reports. The risk of neoplasm and malignancy based on the cases with subsequent resection or flow cytometry and the most common causes of discrepancy were analyzed.

RESULTS

The risk of neoplasm ranged from 41% to 99% and the risk of malignancy ranged from 22% to 99% among the different MSRSGC categories. Lymphoid and myoepithelial rich lesions were the most common miscategorized lesions using the MSRSGC. Reactive changes due to inflammation were associated with overcalls. The most common malignancy in the atypical category was mucoepidermoid carcinomas.

CONCLUSIONS

Myoepithelial and lymphoid rich lesions arising in the salivary gland are associated with a higher risk of misclassification. The use of category IVB in the MSRSGC is appropriate for lesions with abundant myoepithelial cells. Reactive atypia seen in sialadenitis was the most common feature associated with overcall.

Diagnostic utility of fine-needle aspiration cytology in syphilitic lymphadenitis: A case report

Syphilis is a sexually transmitted infection that causes serious health problems without treatment. Detection of syphilis is necessary to stop the spread of the infection. Cytological screeners and pathologists may experience fine-needle aspiration cytology (FNAC) for syphilitic lymphadenitis; however, its characteristic cytological features are rarely reported. We present FNAC cytological features of syphilitic lymphadenitis in a case of a 21-year-old man. He presented with a sore throat and painful neck lymphadenopathy. His swollen and painful neck persisted even with antibiotic treatment. Necrotizing lymphadenitis and lymphoma were clinically suspected. FNAC was taken from the swollen lymph node. Cytologic findings of the specimen showed various inflammatory cells with small-sized vessels arranged in a branching/arborizing fashion. The vessels were surrounded by inflammatory cells, including plasma cells, neutrophils, and macrophages. Perivascular plasma cell cuffing was focally seen along with inconspicuous granulomas. Neutrophils appeared to involve the vascular wall. The cytological findings suggested syphilitic lymphadenitis, and clinical findings and serological tests confirmed primary syphilis with concomitant human immunodeficiency virus infection. Branching/arborizing vessels associated with many plasma cells, vascular involvement of neutrophils, and granulomas may suggest syphilitic infection if the specimen is obtained via FNAC. (189 words).

Utility and Limitations of Fine-Needle Aspiration Cytology in the Diagnosis of Lymphadenopathy

BACKGROUND

Fine needle aspiration cytology (FNAC) is a valuable tool for evaluating lymphadenopathy. The purpose of this study was to assess the reliability and effectiveness of FNAC in the diagnosis of lymphadenopathy.

METHODS

Cytological characteristics were evaluated in 432 patients who underwent lymph node FNAC and follow-up biopsy at the Korea Cancer Center Hospital from January 2015 to December 2019.

RESULTS

Fifteen (3.5%) of the four hundred and thirty-two patients were diagnosed as inadequate by FNAC, with five (33.3%) of these diagnosed as metastatic carcinoma on histological examination. Of the 432 patients, 155 (35.9%) were diagnosed as benign by FNAC, with seven (4.5%) of these diagnosed histologically as metastatic carcinoma. A review of the FNAC slides, however, showed no evidence of cancer cells, suggesting that the negative results may have been due to FNAC sampling errors. An additional five samples regarded as benign on FNAC were diagnosed as non-Hodgkin lymphoma (NHL) by histological examination. Of the 432 patients, 223 (51.6%) were cytologically diagnosed as malignant, with 20 (9.0%) of these diagnosed as tissue insufficient for diagnosis (TIFD) or benign on histological examination. A review of the FNAC slides of these 20 patients, however, showed that 17 (85.0%) were positive for malignant cells. The sensitivity, specificity, positive predictive value (PPV), negative predictive values (NPV), and accuracy of FNAC were 97.8%, 97.5%, 98.7%, 96.0%, and 97.7%, respectively.

CONCLUSIONS

Preoperative FNAC was safe, practical, and effective in the early diagnosis of lymphadenopathy. This method, however, had limitations in some diagnoses, suggesting that additional attempts may be required according to the clinical situation.

Ultrasonographic and cytological characterization of ultrasound-guided fine-needle aspiration cytology of cervical lymph nodes for false-negative and false-positive diagnosis

OBJECTIVES

The primary goal of this study was to examine the ultrasound and cytological characteristics of inconsistent cases (false negatives and false positives)of ultrasound-guided fine-needle aspiration cytology (US-FNAC) of cervical lymph nodes, to investigate factors influencing the diagnostic accuracy of fine-needle aspiration, and to improve diagnostic efficiency.

METHODS

The results of US and FNAC of cervical lymph nodes in 562 cases treated at our institution from February 2019 to June 2021 were retrospectively analyzed. FNAC cytology results were compared with the final diagnostic results (242 surgical resections/core-needle biopsy, 320 cases followed up for more than 1 year), and the final diagnostic results were taken as the gold standard, and the ultrasound features and clinicopathology-related features were systematically retrospectively analyzed in cases of inconsistency.

RESULTS

The overall diagnostic accuracy of US-FNAC for cervical lymph nodes was 94.9%, with a false-negative rate of 6.7% and a false-positive rate of 3.8%. Analyzing the cases, sampling error due to factors associated with ultrasound features, such as larger, more numerous nodes, non-solid, hypoechoic, inhomogeneous, and increased vascularity are the main causes of false-negative diagnosis, while smaller nodules, overlapping cytologic patterns, and overinterpretation by pathologists are associated with false-positive FNAC results.

CONCLUSIONS

Proper interpretation of cytomorphologic and ultrasound features can improve diagnostic accuracy, and diagnostic misdiagnosis should be carefully observed, the identification of both features should be enhanced to reduce interpretation errors and sampling errors and to reduce the rate of misdiagnosis and missed diagnoses in fine needle aspiration of lymph nodes.

A roadmap for a comprehensive diagnostic approach to fine needle cytology of lymph node metastases

OBJECTIVE

Fine needle cytology (FNC) is widely used as a first-line procedure in the diagnostic algorithm of lymphadenopathies. In a metastatic setting, a first-line diagnostic approach identifies non-haematopoietic malignancy; however, cytopathologists could also provide a second diagnostic level, identifying the origin of the primary tumour. This paper outlines a comprehensive and practical approach to the cytological diagnosis of lymph node metastases.

METHODS

Cytological diagnoses of lymph node metastases performed over a 10-year period were selected and divided into two groups. The first group, labelled "oncological," comprised patients with a previous history of malignancy; the second group, labelled "naïve," included patients with no relevant history. Pathology records were retrieved to record microscopic findings, namely, background appearance, group architecture, and specific cell features; data from cell block (CB) preparations were also collected.

RESULTS

Overall, 982 cases were selected: 497 cases (50.61%) in the naïve group, and 485 (49.39%) in the oncological group. Overall, a second diagnostic level was achieved in 834/982 cases (84.92%); cases diagnosed as carcinoma not otherwise specified were more frequent in the naïve group than in the oncological group (17.51% vs. 8.04%, P < 0.01). Notably, although CB material was available in only 44.87% of the naïve cases, we were able to achieve a second diagnostic level thanks to the integration of clinical and cytomorphological findings, plus lymph node topography, in 82.49% of the cases.

CONCLUSION

Our results confirmed that in a metastatic setting, FNC can reliably lead to the identification of the origin of the primary tumour.

[New aspects in fine needle biopsies of the lymph nodes]

BACKGROUND

The cytology of lymph nodes is a cost-effective method with a short turnaround time and low risk to patients that delivers valuable information on the cause of the lymphadenopathies.

OBJECTIVES

To discuss the value of lymph node cytology in the diagnosis of lymph node swellings.

METHODS

Analysis of the causes of the controversially discussed aspects of lymph node cytology. Presentation of the diagnostic groups of lymph node cytology according to the Sydney system.

RESULTS

The technical aspects of lymph node sampling during fine needle biopsy, as well as the subsequent preparation of the correctly fixed direct smears and the triage of the sample for the auxiliary studies, may pose a significant challenge for some puncturers. The whole spectrum of modern pathologic auxiliary studies can be applied to correctly triaged cytologic samples. The diagnoses of fine needle biopsies of the lymph nodes can be divided into five groups according to the recently proposed Sydney reporting system: insufficient/non-diagnostic, benign, atypical, suspicious, and malignant. Further details concerning the diagnosis as well as recommendations on how to proceed are additionally included in cytologic reports.

CONCLUSIONS

The improvement of lymph node sampling as well as the technical aspects of the sample handling, including the application of auxiliary studies, considerably increase the diagnostic value of fine needle biopsy of the lymph nodes. Wide implementation of the usage of the diagnostic groups for reporting fine needle biopsies of the lymph nodes can standardize reporting and improve communication with other clinical specialists.

Diagnostic performance of melanocytic markers for immunocytochemical evaluation of lymph-node melanoma metastases on cytological samples

AIMS

The diagnosis of metastatic cutaneous melanoma (CM) on lymph node fine needle aspiration samples may be challenging and usually requires confirmation by immunocytochemistry. However, the cytological material could be too scant to order a broad panel of markers. In this case, the pathologist is forced to choose the most advantageous antibodies. The most commonly used melanocytic markers include S100, Melan-A, HMB45 and SOX10 but their diagnostic yield on cytological samples has been poorly studied. The current work aimed to evaluate the diagnostic performance of melanocytic markers when applied to cell blocks obtained from fine needle aspiration cytology (FNAC) of lymph node metastases from CM.

METHODS

S100, Melan-A, HMB45 and SOX10 were tested on cell block sections of 38 lymphnode metastases from CM diagnosed by cytology. A combined score was built to evaluate each immunostaining, considering the intensity of the staining and the percentage of stained neoplastic cells.

RESULTS

S100 and SOX10 revealed a higher sensitivity (100%) than Melan-A and HMB45 for the diagnosis of metastatic CM. Furthermore, SOX10 emerged as the melanocytic marker with the best staining performance.

CONCLUSION

SOX10 has a 100% detection rate and the most easily interpretable staining pattern compared with other melanocytic markers. Therefore, it is strongly recommended that SOX10 is included in the minimal immunocytochemical panel for the diagnostic evaluation of lymph node FNAC in patients with suspected CM metastasis.

Observations on hematogones with light chain restriction

Light-chain restricted hematogones (LCR HGs) detected by flow cytometry (FC) may, occur in bone marrow mimicking involvement by a B-cell lymphoma. This phenomenon can present a diagnostic pitfall and negatively impact patient management, and may occur in other organs, including lymph nodes, For this reason, it is recommended to utilize, in case of LCR in lymph node, one additional morphological, phenotypical or molecular criteria for the diagnosis of lymphoma on cytological samples.

Real-world experience with the Sydney System on 1458 cases of lymph node fine needle aspiration cytology

INTRODUCTION

Lymph node (LN) fine needle aspiration cytology (FNAC) is a safe, quick, inexpensive, reliable, and minimally invasive technique for the diagnosis of lymphadenopathies. Recently, an international committee of experts proposed guidelines for the performance, classification, and reporting of LN-FNAC: the Sydney System. We set out to analyse the diagnostic performance of the Sydney System in a retrospective study.

METHODS

We retrieved 1458 LN-FNACs, reformulated the diagnoses according to the Sydney System, and compared them to the histological control where available (n = 551, 37.8%).

RESULTS

The risk of malignancy for each of the five categories was 66.7% for inadequate/insufficient, 9.38% for benign (overall: 0.84%), 28.6% for atypical, 100% for suspicious and 99.8% for malignant. LN-FNAC showed a sensitivity of 97.94%, a specificity of 96.92%, a positive predictive value of 99.58%, and a negative predictive value of 86.30%.

CONCLUSIONS

These data support the usage of LN-FNAC as an agile first-level technique in the diagnosis of lymphadenopathies. The Sydney System supports and enhances this role of LN-FNAC, and its adoption is encouraged. In negative cases, coupled with ancillary techniques, LN-FNAC can reassure the clinician regarding the benignity of a lymphadenopathy and indicate the need for clinical follow-up, which will catch possible false negatives. In positive cases, LN-FNAC can provide sufficient information, including predictive biomarkers, to initiate management and obviate the need for subsequent, more invasive procedures. Given its speed, minimal invasiveness, and low cost, LN-FNAC can be performed in most cases, even when more invasive techniques are not feasible.

Application of Hans Algorithm for Subcategorization of Diffuse Large B-Cell Lymphoma in Fine-Needle Aspiration Biopsy Cytology

INTRODUCTION

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with remarkably variable clinical presentation and outcome. Hans algorithm subclassified DLBCL into prognostically distinct molecular subtypes by using immunohistochemistry (IHC). Fine-needle aspiration biopsy cytology (FNABC) is a first-line diagnostic modality in lymphadenopathy. The study aims to perform IHC on FNABC cell blocks (CBs) for subclassifying according to the Hans algorithm and correlate with case-matched histopathology.

METHODS

This was a retrospective study carried out between January 2017 and December 2019. All DLBCL FNABC cases with CBs and smears and which had follow-up histopathology were included in the study. Detailed cytomorphological evaluation and CD10, B-cell lymphoma 6 (BCL6), and multiple myeloma oncogene 1 IHCs were performed on CBs. The cases are divided into 3 distinct molecular subtypes based on the Hans algorithm as germinal centre B-cell (GCB), activated B-cell (ABC), and unclassified subtypes. The results were compared with the final histopathology.

RESULTS

A total of 44 cases were diagnosed as DLBCL, and 33 cases with sufficient material for further IHC were included in the study. Twelve cases were of the GCB type, 19 were of the ABC type, and 2 remained unclassified. Follow-up histopathology was available in 20 cases. Overall, histopathological concordance was found in 95% of cases (19/20). The single discordant case was classified as GCB on FNABC and was ABC on histopathology.

CONCLUSION

FNABC with CBs is an acceptable alternative to biopsy for providing a complete diagnosis of DLBCL as per the current WHO classification.

Cytomorphological characterisation of angioimmunoblastic T cell lymphoma: a case-control study

AIMS

Angioimmunoblastic T cell lymphoma (AITL) is often misdiagnosed in cytology. Hence, the present study was conducted to identify the distinctive cytomorphological features of AITL in lymph node fine-needle aspirates (LN-FNA).

METHODS

This was a 4-year retrospective case-control study. Cases included LN-FNAs from patients with histopathologically confirmed AITL. The controls included LN-FNAs from patients with histopathologically confirmed reactive lymphoid hyperplasia (RLH; n=25). Eleven cytomorphological features were assessed in all the aspirates; the strength of association was determined by OR, Cramer's V and multiple correspondence analysis (MCA).

RESULTS

Of a total of 22 cases of AITL reported on histopathology, 19 adequate aspirates from 14 patients (63.6%) were available for review. On univariate analysis, 5 of 11 cytomorphological variables were found to be significant for AITL; however, on MCA, 3 of these parameters, viz absence of tingible body macrophages (OR=0.014; V=0.74), presence of atypical lymphoid cells (OR=10.8; V=0.41) and singly scattered epithelioid cells (OR=19.3; V=0.31), were found to be the strongest predictors of AITL.

CONCLUSIONS

The absence of tingible body macrophages, presence of atypical lymphoid cells and singly scattered epithelioid cells in polymorphic LN-FNAs are significant cytomorphological predictors of AITL in comparison with RLH. Knowledge of these diagnostic predictors, supplemented by clinicoradiological correlation and appropriate ancillary studies, can help diagnose AITL on aspiration cytology.

Lymph node FNA cytology: Diagnostic performance and clinical implications of proposed diagnostic categories

BACKGROUND

Despite widespread clinical use, lymph node fine-needle aspiration cytology (LN-FNAC) lacks universal acceptance for definitively diagnosing lymphomas. This is likely due to reports of lower diagnostic performance, inconsistent terminology use in cytopathology diagnostic reports, and only limited data on the clinical implications of LN-FNAC diagnoses. Recently, a uniform LN-FNAC cytopathological diagnostic reporting system was proposed (the Sydney System). This study evaluated LN-FNAC diagnostic performance and risks of malignancy associated with the proposed diagnostic categories.

METHODS

LN-FNAC specimens obtained in 2018-2019, with and without concurrent core biopsy, to evaluate for suspected lymphoma were analyzed (n = 349). LN-FNAC diagnoses were compared with final diagnoses obtained via subsequent tissue biopsy and/or clinical assessment.

RESULTS

The mean patient age was 57.6 years, and 41% were female. LN-FNAC was the initial diagnostic test in 223 (63.9%), and it was used to evaluate for recurrence in 126 (36.1%). LN-FNAC diagnosed 202 hematological malignancies (57.9%), 23 nonhematological malignancies (6.6%), and 124 reactive processes (35.5%). Subsequent tissue biopsy was performed in 42 (12%). The risks of malignancy per diagnostic category were as follows: inadequate, 58.3%; benign, 6.4%; atypical, 69.2%; suspicious, 96.7%; and malignant, 99.3%. LN-FNAC demonstrated up to 96.3% sensitivity, 91.91% specificity, and 87.35% accuracy. Optimal specimen quality and the use of intradepartmental consultation reduced diagnostic error rates in FNA cases without concurrent core biopsy (P = .029 and P = .0002 respectively).

CONCLUSIONS

LN-FNAC is accurate and reliable for the diagnosis of lymphoma. Inadequate LN-FNAC samples should be resampled due to a significant associated risk of lymphoma. The diagnostic performance of LN-FNAC may be improved with good specimen quality and reviews by multiple pathologists. Understanding the risks of malignancy associated with LN-FNAC diagnostic categories will help to guide optimal patient management.

Accuracy of fine-needle aspiration of lymph nodes: A cancer center's experience

INTRODUCTION

Lymph node fine needle aspiration (LN-FNA) is a minimally invasive method of evaluating lymphadenopathy. Nonetheless, its use is not widely accepted due to the lack of guidelines and a cytopathological categorisation that directly relates to management. We report our experience with LN FNA at a large Cancer Center in Latin America.

METHODS

We retrospectively collected cytological cases of lymph node FNA from the department of pathology at AC Camargo Cancer Center performed over a 2-year period. Data extracted included LN location, age, sex and final cytological diagnosis. Patients that had undergone neoadjuvant chemotherapy and/or cases for which the surgery specimen location was not clearly reported were excluded. For those cases with surgical reports, risk of malignancy was calculated for each diagnostic category, along with overall performance of cytology. False positive cases were reviewed to assess any possible misinterpretation or sampling errors.

RESULTS

A total of 1730 LN-FNA were distributed as follows: 62 (3.5%) non-diagnostic (ND); 1123 (64.9%) negative (NEG), 19 (1.1%) atypical (ATY), 53 (3.1%) suspicious for malignancy (SUS), and 473 (27.3%) positive (POS). Surgical reports were available for 560 cases (32.4%). Risk of malignancy (ROM) for each category was 33.3% for ND, 29.9% for NEG, 25% for ATY, 74.2% for SUS and 99.6% for POS. Overall sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were 78.5%, 99.4%, 70.2% and 99.6%, respectively.

CONCLUSION

Lymph node FNA is a very specific and accurate exam, which is reliable in the detection of lymph node metastasis and other causes of lymphadenopathy.

Ultrasound-Guided Fine-Needle Aspiration of Superficial Lymphadenopathy Performed by Interventional Pathologists: The Applicability of the Sydney System from 2 Years of Experience and 363 Cases

INTRODUCTION

The Sydney system proposal for the study and reporting of lymphadenopathy by fine-needle aspiration (FNA) constitutes one of the first attempts to standardize this procedure. Here, we review its applicability.

MATERIALS AND METHODS

A retrospective study in which all ultrasound-guided FNAs (USFNAs) of superficial lymphadenopathy (palpable or not) performed by interventional pathologists in 2 specialized hospital centers were quantified over 2 years. The procedure was systematized, and the diagnoses were reclassified according to the Sydney system categories.

RESULTS

We analyzed 363 USFNAs of lymphadenopathies. The distribution of cases by categories was as follows: insufficient (n = 13; 3.58%), benign (n = 208; 57.30%), atypia of uncertain significance (n = 7; 1.93%), suspicious (n = 21; 5.79), and malignant (n = 114; 31.40%). The risks of malignancy calculated for categories I, II, III, IV, and V were 27%, 3%, 50%, 100%, and 100%, respectively.

CONCLUSION

The implementation of the Sydney system allows the systematization and standardization of the lymph node FNA methodology, with increased efficacy and efficiency. Assimilating the recommendations enables the qualification of the diagnostic procedure.

A Novel Approach to Classification and Reporting of Lymph Node Fine-Needle Cytology: Application of the Proposed Sydney System

Fine-needle cytology (FNC) is a useful diagnostic tool in the first line evaluation of lymphadenopathy of unknown aetiology. Nevertheless, considering the large number of conditions presenting as lymphadenopathy, lymph node cytology represents a challenging scenario. Recently, an expert panel published the proposal of the Sydney system for performing classification and reporting of lymph node cytopathology; the aim of the present study was to evaluate the applicability of this system. Thus, 300 lymph node FNCs performed over 1 year were reviewed and categorized according to the Sydney system classification. Overall, n = 20 cases (6.7%) were categorized as L1-inadequate/non-diagnostic; n = 104 (34.7%) as benign (L2); n = 25 (8.3%) as atypical (L3); n = 13 (4.3%) as suspicious (L4), and n = 138 (46%) as malignant (L5). FNC diagnoses were correlated with histopathologic and clinical follow-up to assess the diagnostic accuracy and the risk of malignancy (ROM) for each diagnostic category. Statistical analysis showed the following results: sensitivity 98.47%, specificity 95.33%, positive predictive value 96.27%, negative predictive value 98.08%, and accuracy 97.06%. The ROM was 50% for the category L1, 1.92% for L2, 58.3% for L3, and 100% for L4 and L5. In conclusion, FNC coupled with ancillary techniques ensures satisfactory diagnostic accuracy and the implementation of the Sydney system may improve the practice of cytopathologists.

Image-guided lymph node fine-needle aspiration: the Johns Hopkins Hospital experience

INTRODUCTION

Although the diagnostic utility of lymph node fine-needle aspiration (FNA) is well established in the evaluation of metastatic malignancy, its value in the diagnosis of lymphoma is more controversial; yet, there is a growing trend among practitioners towards less-invasive procedures such as FNA and core needle biopsy (CNB). The guidelines recently published by the American Society for Clinical Pathology/College of American Pathology (CAP) regarding the workup of lymphoma include recommendations on the value and limitations of FNA.

MATERIALS AND METHODS

We reviewed 1237 image-guided lymph node aspirates from 695 procedures (410 nodes from 360 ultrasound [US]-guided cases, 799 from 309 endobronchial ultrasound [EBUS], 25 from 23 endoscopic ultrasound [EUS], and 3 from 3 computed tomography [CT]).

RESULTS

The majority (40 of 46, 87%) of lymph nodes suspected of lymphomatous involvement were aspirated under ultrasound. Core needle biopsy [CNB] was obtained for 41 (89%) lymph nodes, including all 40 US specimens. Flow cytometry (FC) was performed on 37 (80%) aspirates; aspirates without FC were from patients who had a history of Hodgkin lymphoma, or showed granulomata or non-hematologic malignancy onsite. Thirty-one (67%) lymph nodes were sent for review by hematopathology. Forty-two (91%) lymph node FNA/CNB yielded actionable diagnoses. Seventeen of 241(7%) cases aspirated for other indications (14 US, 3 EBUS) were involved by a lymphoproliferative process. All were reviewed by hematopathology. All 14 US cases had FC and CNB.

CONCLUSION

Our institutional approach towards lymph node cytopathology for lymphoma workup appears to be in accordance with the new CAP guidelines, and demonstrates a potential triage and workflow model for lymph node FNA specimens that allows for accurate diagnosis in cases where lymphoma is a consideration.