Fine-Needle Aspiration Diagnosis of Lymphoma Based on Cytomorphology Alone: How Accurate is it? - A Cyto-Histopathology Correlative Study

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.

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.

Study of Extramedullary Lymphoblastic Lymphoma (LBL) Diagnosed by Flowcytometric Immunophenotyping (FCI) on Fine Needle Aspirate (FNA) Sample-A Case Series of 18 Cases

Background

Lymphoblastic lymphoma (LBL) accounts for about 2% of all lymphomas. Recognition of T/B-LBL albeit of their rareness is very important as they present as localized diseases with low tumor burden. They can present both at nodal and extranodal sites. Limitation of diagnosis and classification of lymphoma on fine needle aspirate (FNA) can be minimized by clubbing it with flowcytometric immunophenotyping (FCI) to ensure diagnostic accuracy rapidly.

Aim

Study of a series of 18 cases of LBL to assess the utility of FCI on FNA and effusion samples in extramedullary LBL.

Methods and Material

FCI was done on FNA and effusion samples from 130 morphologically diagnosed/suspicious cases of lymphoreticular malignancy, followed by peripheral blood and bone marrow (BM) examination. The patients diagnosed to have B/T LBL, based on WHO 2017 classification, were selected for further analyses.

Results

FCI of 130 cases showed 91 mature and 18 precursor lymphoid neoplasms. These 18 cases were from lymph nodes (11), pleural fluid (03), and soft tissue masses (04). Peripheral blood and BM of 15/18 cases were normal of which FCI revealed T-LBL (11) and B-LBL (04). Two cases (both T LBL) showed BM involvement (<25%), while one case of B-LBL which was misdiagnosed as mature lymphoma by immunohistochemistry (IHC) evolved as B ALL.

Conclusions

Diagnosis of extramedullary B/T-LBL needs comprehensive evaluation of clinical presentation, cytomorphology, and immunophenotyping. Rapid and accurate diagnosis by FCI on FNA and effusion samples allows early therapeutic decisions, thereby avoiding leukemic dissemination.

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.

Evaluating Different Quantitative Shear Wave Parameters of Ultrasound Elastography in the Diagnosis of Lymph Node Malignancies: A Systematic Review and Meta-Analysis

Shear wave elastography (SWE) has shown promise in distinguishing lymph node malignancies. However, the diagnostic accuracies of various SWE parameters that quantify tissue stiffness are yet to be demonstrated. To evaluate the pooled diagnostic accuracy of different SWE parameters for differentiating lymph node malignancies, we conducted a systematic screening of four databases using the PRISMA guidelines. Lymph node biopsy was adopted as the reference standard. E_max (maximum stiffness), E_mean (mean stiffness), E_min (minimum stiffness), and E_sd (standard deviation) SWE parameters were subjected to separate meta-analyses. A sub-group analysis comparing the use of E_max in cervical (including thyroid) and axillary lymph node malignancies was also conducted. Sixteen studies were included in this meta-analysis. E_max and E_sd demonstrated the highest pooled sensitivity (0.78 (95% CI: 0.69-0.87); 0.78 (95% CI: 0.68-0.87)), while E_mean demonstrated the highest pooled specificity (0.93 (95% CI: 0.88-0.98)). From the sub-group analysis, the diagnostic performance did not differ significantly in cervical and axillary LN malignancies. In conclusion, SWE is a promising adjunct imaging technique to conventional ultrasonography in the diagnosis of lymph node malignancy. SWE parameters of E_max and E_sd have been identified as better choices of parameters for screening clinical purposes.

Global patterns of non-Hodgkin lymphoma in 2020

We evaluated the global patterns of non-Hodgkin lymphoma (NHL) in 2020 using the estimates of NHL incidence and mortality in 185 countries that are part of the GLOBOCAN 2020 database, developed by the International Agency for Research on Cancer (IARC). As well as new cases and deaths of NHL, corresponding age-standardized (world) rates (ASR) of incidence and mortality per 100 000 person-years were derived by country and world region. In 2020, an estimated 544 000 new cases of NHL were diagnosed worldwide, and approximately 260 000 people died from the disease. Eastern Asia accounted for a quarter (24.9%) of all cases, followed by Northern America (15.1%) and South-Central Asia (9.7%). Incidence rates were higher in men than in women, with similar geographical patterns. While the incidence rates were highest in Australia and New Zealand, Northern America, Northern Europe and Western Europe (>10/100 000 for both sexes combined), the highest mortality rates (>3/100 000) were found in regions in Africa, Western Asia and Oceania. The large variations and the disproportionately higher mortality in low- and middle-income countries can be related to the underlying prevalence and distribution of risk factors, and to the level of access to diagnostic and treatment facilities.

Role of Polyamines as Biomarkers in Lymphoma Patients: A Pilot Study

Lymphomas represent a heterogeneous and widely diversified group of neoplastic diseases rising from a variety of lymphoid subsets at heterogeneous differentiation stages. These lymphoproliferative disorders lead to the clinicopathological complexity of the classification of lymphoid neoplasms, describing to date more than 40 categories of non-Hodgkin’s lymphoma (NHL) and 5 categories of Hodgkin’s lymphoma (HL). Inflammation has been shown to play a key role in the evolution of cancer diseases, and it might be interesting to understand their role also in the context of lymphoid neoplasms. Among circulating biomarkers, the role of polyamines belonging to the arginine and lysine metabolism is relevant. Through modern analytical methods, such as mass spectrometry (MS), we are enabled to increase knowledge and improve our understanding of cancer metabolism. In this study, high-resolution mass spectrometry was used in combination with high-performance liquid chromatography (LC-HRMS) to measure serum levels of polyamines and identify possible diagnostic circulating biomarkers, potentially allowing a more accurate assessment of the diagnostic stratification of lymphoma patients and robust comparisons between different patient groups.