Cytological Findings for the Diagnosis of Primary Thyroid Mucosa-Associated Lymphoid Tissue Lymphoma by Fine Needle Aspiration

Abstract

Objective: We examined cytological findings for the diagnosis of primary thyroid mucosa-associated lymphoid tissue (MALT) lymphoma by fine needle aspiration. Study Design: During the study period of 4 years, a total of 101 cases including 51 MALT lymphomas, 20 Hashimoto's thyroiditis (HT), and 30 diffuse large-cell B-cell lymphomas were cytologically examined. MALT lymphomas were divided into 44 common MALT and 7 MALT lymphomas with extreme plasmacytic differentiation (MALT-EPCD). Results: (1) Small- to medium-sized cells displaying irregularly shaped nuclei with prominent nucleoli (ISN-PN) were neoplastic cells. (2) In the case of a frequency of plasma cells (PC) below 15%, the accuracy rate for distinguishing common MALT from HT was 97% for ISN-PN cell frequencies above 20% in combination with the presence of lymphoepithelial lesion clusters (LELC) and mountain range-like clusters (MRLC). The frequency of large-sized cells was below 15% in common MALT. (3) In the case of a frequency of PC above 15%, cases with a sum of PC and ISN-PN cells above 30% were MALT-EPCD. (4) MRLC were cell clusters derived from regions of follicular colonization, and LELC were cell clusters from lymphoepithelial lesions of MALT lymphomas. Conclusion: Useful cytological criteria for the diagnosis of thyroid primary MALT lymphoma, such as neoplastic cells and cell clusters, were defined.

Primary and isolated thyroid Hodgkin’s lymphoma: A case report

“…Although FNA has become the procedure of choice for the diagnosis of any thyroid tumor it has yielded mixed results asserting the presence of MALT so that core or open biopsy and even surgical excision (as in our case) is decisive for diagnosis [14].…”

An Unwonted Clinicopathological Subtype of Thyroid Primary Lymphoma

“…Although FNAB has become the procedure of choice for the diagnosis of any thyroid tumor it has yielded mixed results asserting the presence of MALT so that core or open biopsy and even surgical excision (as in our case) is decisive for diagnosis. (10) Combined pathology and immunohistochemistry may specify microscopy of these lesions orienting therapeutic planning and predicting prognosis of the patients. 11Ultrasound showed irregular, psudocystic, hypoechoic mass with variable edge characteristics, where echogenicity is less than that of the adjacent neck musculature.…”

The diagnosis of primary thyroid lymphoma by fine‐needle aspiration, cell block, and immunohistochemistry technique

“…Despite its expected limitations for the diagnosis of PTL, FNA remains the most frequently used tool for the evaluation of thyroid nodules. Several studies have examined the applications of FNA for PTL 16‐23 . The joint application of FNA, CB, and IHC results in a greater percentage of accurate tissue diagnoses of salivary gland neoplasms and lacrimal gland tumors compared with cytological smears from the previous reports 24,25 ; however, there have been no studies for the diagnosis of PTL.…”