A stepwise approach to fine needle aspiration cytology of lymph nodes

Institutional Experience of Lymphoproliferative Disorders with Initial Diagnosis Made via Fine Needle Aspiration at Otolaryngology Clinic

BACKGROUND

This study characterizes lymphomas presenting as palpable head and neck masses and evaluates the role of fine needle aspiration (FNA) and flow cytometry (FC) in diagnosis.

DESIGN

A 5-year retrospective review of FNAs performed by pathologists in an ENT clinic identified cases with a predominant lymphoid population that lacked an epithelial component. Cytology, FC, and subsequent surgical pathology diagnoses were correlated.

RESULTS

Of 821 FNAs, 154 (19%) met selection criteria. Reactive lymph nodes accounted for 43% (67/154), with most diagnosed as 'negative for malignancy,' except one 'atypical' (ATY) case. Lymphoma was confirmed in 57% (87/154) of cases, categorized as ATY (55%), suspicious for lymphoma (SFM) (36%), or positive for lymphoma (PFM) (9%). Lymphoma patients were older (median 66 vs. 46 years). Thyroid and salivary gland lymphomas typically indicated systemic involvement, except for two cases of marginal zone lymphoma (MZL) in patients with Sjögren syndrome. FC alone had a sensitivity of 67.5% for detecting lymphoma, but when combined with cytology, the sensitivity increased to 100%. The combined approach maintained a specificity of 98%. More abnormal clonal cells were identified by FC in PFM cases compared to SFM or ATY cases (P=0.004). Cytologic atypia with negative FC occurred in 29% of lymphomas, including Hodgkin and diffuse large B-cell lymphoma (DLBCL).

CONCLUSION

Lymphomas presenting as neck masses are diverse, with FNA playing a key diagnostic role. Cytologic atypia and FC complement each other, as some cases show minimal atypia but positive FC, while others show significant atypia with negative FC.

Pitfalls in the Cytological Diagnosis of Nodal Hodgkin Lymphoma

BACKGROUND

Hodgkin lymphoma (HL) is a hematopoietic neoplasm characterized by malignant Reed-Sternberg (RS) cells in an inflammatory background. Although the cytological features of HL are well elucidated in literature, yet many postulated factors cause its misdiagnosis. This study aims to assess the diagnostic reliability of fine needle aspiration cytology (FNAC) in HL and evaluate the factors contributing to a false-negative and false-positive diagnosis, taking histopathology as the gold standard.

METHODS

This was a retrospective study in which 47 cases of HL diagnosed on histopathology were compared with their prior cytological diagnosis.

RESULTS

The patient's age ranged from 3 to 80 years (median: 36 years) with a M:F ratio of 2.9:1. Lymph node aspirations were performed from multiple anatomical sites, out of which the cervical was the most common (57.8%). FNAC was inconclusive in two cases due to unsatisfactory smears. The false-negative diagnosis of reactive lymphadenitis was given in four cases, and false-positive in four cases, which included three cases of non-HL, and one case of malignant small round blue cell tumor. The overall diagnostic accuracy of FNAC in the diagnosis of HL was 82.2%.

CONCLUSIONS

The cytological diagnosis of HL can be challenging when classic RS cells are absent. Contributing factors for a false-negative diagnosis include obscuring reactive inflammatory cells, fibrosis of the involved lymph nodes, partial involvement of the lymph node, and misinterpretation. A thorough clinical examination with evaluation of FNAC smears from multiple areas, and ancillary tests help improve the diagnostic accuracy of cytological diagnosis.

Efficiency of Fine-Needle Aspiration (FNA) in Relation to Tru-Cut Biopsy of Lateral Neck Swellings

Background Lateral neck masses have always been difficult to diagnose without proposing a differential diagnosis. Fine-needle aspiration (FNA) was proposed to be a cost-effective method and less invasive than a tru-cut biopsy and may provide a provisional diagnosis in relation to cytopathology. FNA has also been shown to improve the diagnosis of neck masses such as cervical lymphadenopathy, neck cysts, and parotid masses, whether malignant or benign. This study aims to evaluate the accuracy of FNA cytopathology versus a tru-cut biopsy histopathological examination. Materials and methods This study was conducted retrospectively in King Hussein Medical Hospital, Royal Medical Services, Hashemite Kingdom of Jordan, from January 2019 to January 2024. Ethical approval was taken to conduct this study with reference number 06/2024. All patients included in this study have given verbal and written consent to perform FNA and surgical tru-cut biopsy. The inclusion of patients was based on any person above the age of 16 who underwent an FNA followed by a surgical biopsy to correlate with the primary diagnosis. Exclusion criteria involved any patient who missed one of the above criteria. Statistical analysis was performed using IBM SPSS v29 (IBM Corp., Armonk, NY, US) with significant results considered with a p-value <0.05. Results A total of 107 patients were included in this study. A correlation between FNA results and final histopathological biopsy was done with an accuracy of 90.6%, specificity of 94.3, predictive positive value of 73.6%, and negative predictive value of 94.3%. There was a statistical significance between FNA and tru-cut biopsy with a p-value of <0.001. Conclusion FNA is a great tool to consider when diagnosing lateral neck swellings. Since it was statistically significant, FNA should be considered for any lateral neck swelling before any surgical tru-cut biopsy for a definitive diagnosis.

The Incidence of Thyroid Cancer in Bethesda III Thyroid Nodules: A Retrospective Analysis at a Single Endocrine Surgery Center

BACKGROUND

Fine-needle aspiration cytology (FNAC) is widely used to diagnose and monitor thyroid nodules. The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is the standard for interpreting FNAC specimens. The risk of malignancy in Bethesda III nodules, also known as Atypia of Undetermined Significance (AUS), varies significantly throughout several studies published worldwide. This retrospective study examines the risk of cancer in thyroid FNAC categorized as Bethesda III as identified in the final histopathology of thyroidectomy specimens at a single endocrine surgery center.

METHODS

This retrospective cohort analysis included 1038 consecutive patients who underwent elective thyroid surgery with complete follow-up data between January 2020 and March 2024. Preoperative data on clinical and pathological characteristics have been collected. The final histopathology report from the thyroidectomy specimen was compared to the results of the preoperative FNAC on nodules that were judged to be Bethesda category III. Statistical methods were performed using SPSS version 29.

RESULTS

A total of 670 ultrasound-guided FNACs (64.5%) performed during the study period were included in the final analysis. The study population was predominantly female, represented by 79.6% of patients with a mean age of 42.5 (SD 12.1), while 20.4% were male and significantly older with mean age of 45.13 years (p = 0.02). The FNAC inadequacy rate was 5.1%, which was associated with a high risk of malignancy (6 out of 34; 17.6%). Out of the total sample size of 170 patients classified as group III, 57 were found to have malignancies in final surgical histopathology, representing 33.5% of the cases within this category. The secondary gender-related outcome analysis showed that female patients classified under the Bethesda II category had a significantly higher risk of malignancy, with a rate of 21.2%, compared to males who had a malignancy rate of 3.4% in the same Bethesda category (p = 0.001, chi-square test). However, the female patients exhibited prognostically superior non-invasive tumors compared to male individuals (p = 0.02, chi-square test).

CONCLUSION

This study's results indicate that Bethesda categories II and III are associated with a higher risk of malignancy in comparison to the reports of the first and third editions of the TBSRTC, particularly for female patients classified under category II.

Immunocytochemical markers, molecular testing and digital cytopathology for aspiration cytology of metastatic breast carcinoma

Fine-needle aspiration cytology (FNAC) is a versatile diagnostic procedure uniquely suited for tissue biopsy of breast carcinomas and axillary metastases and/or recurrences. With the expanding treatment options and accompanying theragnostic tests, it is crucial to recognize the developments on ancillary testing and digital cytopathology techniques related to aspiration cytology of metastatic breast carcinoma. In this review, we aim to summarize and update the evidence of immunocytochemistry, for the detection of carcinoma cells (epithelial markers), confirmation of breast primary (breast-specific markers), assessment of surrogate immunostains (hormone receptors, ki-67 proliferative index and HER2) and theragnostic biomarkers, with discussion on potential diagnostic pitfalls, followed by the application of molecular tests, and digital cytopathologic techniques for assessing metastatic breast carcinoma in cytology.