Utilility of flow cytometry as ancillary study to improve the cytologic diagnosis of thyroid lymphomas

Abstract

Results: A final diagnosis of lymphoma was given in 13 of 35 (37.1%) specimens. Among the 22 cases considered negative for lymphoma by FC, 11 were diagnosed as thyroiditis by cytology, 7 as reactive, 2 were anaplastic carcinoma, and 2 cases were considered cytologically suspicious for lymphoma but were not confirmed by further investigations. Histology on core biopsy or molecular analysis was available in 12 of 13 lymphoma cases (92.3%). Data obtained by the combination cytology/FC were confirmed in all cases on histology biopsies. Correlation with histology showed a sensitivity and a specificity of 100% for the combination cytology/FC. Conclusions: FC is an important additional test that can contribute with cytology to the identification of lymphomas of the thyroid. FC can detect the presence of small neoplastic lymphocyte populations and may contribute to the diagnosis of cases in which the lymphoid infiltrate is difficult to interpret on cytology alone. V C 2014 International Clinical Cytometry Society

Preoperative diagnostic algorithm of primary thyroid lymphoma using ultrasound, aspiration cytology, and flow cytometry

“…Assessment of the κ/λ light chain ratio with FC is one of the most important procedures, enabling differentiation between benign lymphoproliferative lesions and lymphoma. When the κ/λ light chain ratio is greater than 3 to 4:1 or less than 1:2 to 3, clonal proliferation is present [6,[13][14][15]. However, some lymphomas do not satisfy this criterion [16,17].…”

“…To improve the limited diagnostic tools, ancillary techniques have been recently used. Flow cytometry (FC) can detect small-sized primary thyroid lymphoma and may contribute the diagnosis of lymphoid lesions that are difficult to interpret with FNAC alone [6]. The aims of this report were to clarify the diagnostic significance of US, FNAC, and FC for primary thyroid lymphoma, and to establish a preoperative diagnostic algorithm for primary thyroid lymphoma by combining the use of these three diagnostic tools.…”

Mantle cell lymphoma involving the thyroid: a case report

“…Guidelines for the investigation of lymphoproliferative disorders of the thyroid are still missing, and rare publications have addressed this issue. 2,3 The current WHO classification of tumours of haematopoietic and lymphoid tissues recommends as a standard of practice the use of a multi-parametric approach for sub-classifying NHL, which includes confirmation of B-cell clonality either by FC or polymerase chain reaction (PCR). ROSE as part of an algorithm for handling thyroid FNA with a rich lymphoid component ensures appropriate triage and aliquoting of the sample for ancillary testing.…”

“…6 Similar findings were reported in different series of thyroid lymphomas diagnosed by FNA. 2,3 Other subtypes are even more uncommon, including MCL, which is found in less than 1% of thyroid lymphomas. 6 No lymphoepithelial lesion (LEL) was identified.…”

“…1 The cytological diagnosis of lymphomas involving the thyroid gland is aided by clinical, morphological and immunophenotypical features. 2,3 With the current report, we want to highlight the importance of the previous history of lymphoma as an important clinical criterion, and the role of rapid on-site evaluation (ROSE) in triaging the cases that need immunophenotyping and fluorescence in situ hybridization (FISH) studies when handling a lymphocyte-rich thyroid aspirate, in order to distinguish the rare thyroid lymphomas from the common lymphocytic thyroiditis.…”