Extranodal Lymphoproliferative Processes and Flow Cytometry

Abstract

Objective: Fine-needle aspiration (FNA) cytology is a safe and cost-effective technique for the diagnosis of lymphoproliferative processes, especially when correlated with clinical and imaging studies. However, cytology alone may be unable to detect a lymphoid neoplastic process, as architectural features are less obvious than in histologic preparations and, in certain cases, reactive processes may mimic lymphoma. Flow cytometry (FC) has been recognized as an important ancillary technique in the diagnosis of lymphoid neoplasms and it can be used in conjunction with FNA in the evaluation of lymphoproliferative processes. Study Design: We performed a review of the published literature concerning FC applied to the detection of salivary glands and thyroid lymphoproliferative processes, which are frequently related to autoimmune diseases and difficult to diagnose by cytomorphology alone. Results: FC is able to detect and subtype non-Hodgkin lymphomas and may contribute to the exclusion of a neoplastic process in cytologically unclear cases. Conclusions: FC can be successfully applied in the differential diagnosis of lymphoproliferative processes in the head and neck region. The FNA-FC combined approach can reduce time to therapy and may prevent unnecessary surgical biopsies.

Thyroid FNAC: Causes of false‐positive results

“…Aspirates in the florid lymphoid phase may be entirely composed of lymphocytes and may be confused with low‐grade lymphoma (Figure ). Detailed clinical findings and flow cytometry would be very useful in this differential diagnosis . Serology testing for thyroid autoantibodies should be part of the workup of cases of lymphocytic thyroiditis and in presence of a positive autoantibody test in an atypical cytology the risk of malignancy differs if the test is negative.…”

A retrospective study of flow cytometric characterization of suspected extranodal lymphomas in dogs

“…9,11,15,31 Conversely, in human medicine, FC is routinely included in the diagnostic workup of extranodal lymphomas. 3,19,32,34,37,38 In addition, FC is a safe and minimally invasive technique to confirm the diagnosis of lymphoma in cats, a species with a high prevalence of extranodal forms. 14,23 Given these premises, the aim of our retrospective study was to describe FC results in a case series of suspected canine extranodal lymphomas.…”

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

“…As a proof-ofconcept, we present the dot blot-based gating strategy of a small lymphocytic lymphoma case in Figure 5A-L. As mentioned before, FNA FC can be useful to detect lymphoma recurrence, but there is still a question of whether it is feasible to be used in the primary diagnosis of lymphoma [6,10,11]. This principle has reached the point in which there are authors that consider FNA FC sufficient to detect head and neck lymphomas without the need for subsequent histological examination on surgical biopsy [12]. Moreover, FNA FC showed its utility in a deep-seated lymphoma setting where surgical biopsy would present a higher degree of difficulty and risk [13][14][15].…”