Impact of Flow Cytometry in Thyroid Cytopathology

Abstract

Background: Fine-needle aspiration (FNA) is a useful diagnostic tool for preoperative evaluation of thyroid nodules. However, cytomorphology alone has poor accuracy for the diagnosis of lymphoproliferative disorders involving the thyroid. This study reviews our experience with flow cytometry on thyroid FNA and correlation with surgical follow-up at The Johns Hopkins Hospital. Methods: The 11,118 thyroid FNAs performed over a 20-year period were reviewed for clinical flow cytometry data (n = 62) or a subsequent diagnosis of lymphoma in the thyroid without flow cytometry data (n = 2). Result: Sixty-four cases (0.6%) were included out of 11,118 thyroid FNAs collected over a 20-year period. Lymphoma was diagnosed 13 times. In 8 cases, both cytomorphology and flow cytometry arrived at the correct diagnosis. Cytomorphology alone made the correct diagnosis twice in the absence of flow cytometric results; flow cytometry made the diagnosis once in the absence of suspicious morphology. Neither flow cytometry nor cytomorphology made the correct diagnosis in 2 sparsely cellular cases. Conclusion: The combination of cytomorphology and flow cytometry is a useful diagnostic modality for the work-up of lymphocyte-rich thyroid nodules that show atypical lymphocyte populations.

Fine Needle Cytology and Flow Cytometry in Hashimoto Thyroiditis and Primary Thyroid Lymphoma

“…Clinical and US data of these 2 cases were consistent with the FC and/or the FNC diagnoses of TL and the histological examinations confirmed the TL diagnoses. Therefore, we think that the report of 2 ‘clonal', non-lymphomatous HT cases in the series of Boonyaarunnate et al [1] may further confirm the possible occurrence of small B-cell populations with light chain restriction in a variable number of HT cases. We would also like to stress the risk of overevaluating their meaning, especially in the absence of any clinical and US evidence of TL, and in our opinion the data of Boonyaarunnate et al [1] may support these data, too.…”

“…We read with great interest the article ‘Impact of flow cytometry in thyroid cytopathology' by Boonyaarunnate et al [1] published in the last November-December issue of Acta Cytologica . In this study, the authors investigated 13 cases of primary thyroid non-Hodgkin lymphoma (TL) and 33 cases of Hashimoto thyroiditis (HT) by fine needle cytology (FNC) and flow cytometry (FC).…”

Rapidly Enlarging Midline Neck Mass

“…1 The annual incidence of primary thyroid lymphoma (PTL) has been reported to be 1 to 2 cases per million. 2 Most thyroid lymphomas are nonHodgkin B-cell lymphomas, such as diffuse large B-cell lymphoma (DLBCL) and extranodal marginal zone lymphoma (ENMZL).…”

Extranodal Lymphoproliferative Processes and Flow Cytometry

“…The literature that we are aware of that reports the use of FC is listed in table 2[29,30,31,32,33,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58]. Two papers were case reports [48,54]; some included thyroid specimens in studies performed to assess the overall value of FNA in NHL diagnosis [29,30,32].…”

“…Two papers were case reports [48,54]; some included thyroid specimens in studies performed to assess the overall value of FNA in NHL diagnosis [29,30,32]. Among the studies carried out to evaluate the role of cytology in the differential diagnosis of thyroid lymphoproliferative processes, only three reports focused on the role played by FC [42,56,57]. Our study [42] and the work by Boonyaarunnate et al [56] reported the highest number of lymphomas identified, both concluding that the combined use of FNA-FC plays a fundamental role in the identification of this rare form of extranodal lymphoma.…”