Image-guided fine-needle aspiration cytology and flow cytometry phenotyping of neck lymphadenopathy for the diagnosis of recurrent lymphoma

Differential Diagnosis of Malignant Lymphadenopathy Using Flow Cytometry on Fine Needle Aspirate: Report on 269 Cases

Introduction: Fine needle aspiration (FNA) is frequently the first noninvasive test used for the diagnostic workup of lymphadenopathy. There have been many studies showing its usefulness, especially in conjunction with other techniques for the diagnosis of lymphoma, but it remains inferior to histological examination. The data regarding this subject have mostly been reported mostly from first-world countries, but are scarce for emerging economies. Thus, the current study assesses the agreement between fine needle aspiration flow cytometry (FNA FC) and histology in the aforementioned region. Material and Methods: We conducted a retrospective study including the FNA FC adenopathy diagnoses made between January 2011 and December 2016 at the Tygerberg Hospital, Cape Town, South Africa. Additional variables included were the histological diagnosis, sex and age of the included patients. Results: In the descriptive part of the current study, 269 FNA FC samples were included. The most frequent diagnoses made on these were represented by B-cell lymphoma, reactive adenopathy, no abnormality detected (NAD), and non-hematological malignancy. In the analytical part of the current study, there were 115 cases included that had both valid FNA FC and histological diagnoses. It could be observed that FNA FC can correctly diagnose B-cell lymphoma in most cases, but it is a poor diagnostic tool especially for Hodgkin lymphoma in this setting as only a four-color flow cytometer was available for diagnosis. Moreover, FNA FC diagnosis of reactive adenopathy and of no abnormalities detected was shown to frequently hide a malignant disease. Conclusion: In countries with scarce resources, FNA FC represents a useful diagnostic tool in the case of B-cell lymphoma, but may misdiagnose reactive adenopathy. Thus, FNA FC should be used in a case-specific manner, in addition to as a screening tool, with the knowledge that in cases with a high clinical suspicion of lymphoma, histological diagnosis is a necessity.

Formulating a Treatment Plan in Suspected Lymphoma: Ultrasound-Guided Core Needle Biopsy Versus Core Needle Biopsy and Fine-Needle Aspiration of Peripheral Lymph Nodes

OBJECTIVES

Image-guided tissue sampling in the workup of suspected lymphoma can be performed by core needle biopsy (CNB) or CNB with fine-needle aspiration (FNA). We compared the yield of clinically actionable diagnoses between these methods of tissue sampling.

METHODS

All ultrasound-guided percutaneous peripheral lymph node biopsies from 2010 to 2017 at a single institution were retrospectively reviewed for biopsy type (CNB versus CNB + FNA), prior diagnosis of lymphoma, size of the target lymph node, number of cores, length of core specimens, and pathologic diagnosis. Lymphoma and lymphoid tissue were included; metastatic disease and nonlymphoid tissue were excluded. An oncologist specializing in lymphoma independently determined whether an actionable diagnosis could be made with the pathologic results in the context of the patient's medical record. χ² analyses and univariable/multivariable logistic regression models were used for statistical analyses.

RESULTS

Of 578 lymph node biopsies, 306 (53%) had a prior diagnosis of lymphoma; 273 (47%) were CNB, and 305 (53%) were CNB + FNA. There was no significant difference between biopsy types (CNB versus CNB + FNA) in the number of cores (median [25th, 75th percentiles], 3 [3, 4] versus 4 [3, 4]; P = .47) or total length of tissue (4.1 [2.5, 6.1] versus 3.7 [2.3, 6] cm; P = .09). There was no difference in obtaining an actionable diagnosis between biopsy types after controlling for a known history of lymphoma (P = .271) or after controlling for the number of core specimens (P = .826).

CONCLUSIONS

In cases of suspected lymphoma, CNB without FNA was sufficient to obtain an actionable diagnosis.