Axillary lymph node metastasis: Fine‐needle aspiration biopsy sensitivity as a function of node size, percent replacement of lymph node by tumor and tumor deposit size

Abstract

BackgroundFine‐needle aspiration (FNA) is commonly used to investigate lymphadenopathy of suspected metastatic origin. While diagnostic accuracy of FNA for lymph node disease is well described, the relationship between node size, percent tumor replacement, and size of metastatic deposit with diagnostic accuracy is less well documented.MethodsAll axillary lymph nodes undergoing ultrasound‐guided FNA for suspected breast metastases were correlated with subsequent surgical excision specimens. FNAs were judged as positive or negative for malignancy and the percent of false negative FNAs was correlated with node size, percent tumor replacement and size of metastatic depositResultsSensitivities were calculated for nodes greater than 15 mm (92%), nodes 11 to 14.9 mm (83%), nodes 7 to 10.9 mm (61%), and for nodes less than 7 mm (60%). Sensitivity increases with increasing node size (P = .001). Percent tumor replacement correlated with sensitivity: 90% or greater replacement (85%) 60% to 89.9% replacement (75%), 40% to 59.9% replacement (75%) and less than 39.9% replacement (64%)(P < .001). Metastases size correlated with sensitivity: metastases greater than 10 mm (94%), 6 to 9.9 mm (70%), 4 to 5.9 mm (54%), and less than 4 mm (72%).ConclusionsPercentage of false negative FNAs associate with investigation of metastatic disease correlates with node size, size of metastatic deposit and percentage of nodes replaced by tumor. Lymph nodes smaller than 7 mm, deposit diameter less than 6 mm and percentage replacement of less than 40% have the highest percentage of false negative results.

Surgical Lymph Node Biopsy for the Diagnosis of Lymphoma: A Case Report

“…Sampling errors using CNB and FNA may result in misdiagnoses and incomplete subclassification of lymphoma. Prior studies document that CNB provided the correct lymphoma diagnosis in only 66% of patients, provided an incorrect lymphoma subtype in 18% of patients, yielded inconclusive results in 14% of patients, and misidentified the tissue as benign in 2% of patients [16][17][18][19].…”

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

“…The diagnosis of lymphoma on FNA alone remains controversial and practice guidelines typically advise against FNA alone in the primary diagnosis of lymphoma as reported sensitivity especially in the absence of ancillary studies has varied 14 . In contrast, FNA‐only biopsies for metastatic disease are generally more accepted, have typically demonstrated high diagnostic performance and can frequently identify primary tumour origin, particularly if lymph node size is greater than 0.7 cm with greater than 40% involvement by metastasis 16,17 …”

“…14 Current National Comprehensive Cancer Network guidelines discourage both FNA and CNB in the primary diagnosis of lymphoma and suggest that a SB should be obtained if possible. 15 Therefore, it is important for pathologists and clinicians to recognize both the utility and limitations of small biopsies.…”

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

“…Moreover, FNC can also identify some specific morphological features, indicative of certain types of tumour differentiation, such as adenocarcinomas and sarcomas, as well as a pool of possible primary origins. Although the cytological features of metastases from almost any type of malignant tumour have been described, most of the published data generally focus on FNC of metastatic lymph nodes from single specific neoplasms or from single topographic locations 8–17 . Unfortunately, the reality in routine clinical practice is much more complex than that.…”

“…Although the cytological features of metastases from almost any type of malignant tumour have been described, most of the published data generally focus on FNC of metastatic lymph nodes from single specific neoplasms or from single topographic locations. 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 Unfortunately, the reality in routine clinical practice is much more complex than that. Indeed, lymphadenopathies of various anatomical districts still pose a great diagnostic challenge for cytopathologists.…”