Long-Term Outcomes of 107 Cases of Primary Thyroid Mucosa-Associated Lymphoid Tissue Lymphoma at a Single Medical Institution in Japan

Primary thyroid B-cell lymphoma: molecular insights into its clonal evolution and relapse

Primary thyroid lymphomas comprise largely extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (EMZL) and diffuse large B-cell lymphoma (DLBCL), followed by follicular lymphoma (FL). They commonly develop from a background of Hashimoto's thyroiditis (HT), where dysregulated immune responses trigger autoreactive infiltrates and drive clonal B-cell evolution. To understand how these lymphomas and their relapse evolve, we investigated 10 cases by mutation profiling, including five with metachronous lymphomas [primary lymphoma (EMZL = 4, DLBCL = 1) with local relapse (EMZL = 3, DLBCL = 2)], one composite EMZL and Epstein-Barr virus (EBV)-positive DLBCL, and four lymphomas (EMZL = 3, FL = 1) with prior or subsequent biopsy showing HT. In four cases with metachronous lymphomas, both common and distinct variants were seen in the paired lesions, indicating their divergent evolution from clonally related lymphoma precursor (CLP) cells. In the remaining case with metachronous lymphomas, the relapsed lesion was progressed from the initial lymphoma. In the case with composite lymphoma, the EBV-positive DLBCL was transformed from EMZL. Finally, in the four cases with paired lymphoma and HT biopsies, two showed shared mutations between the paired lesions, indicating involvement and divergent evolution from CLP cells. Thyroid lymphoma relapse may frequently develop via divergent evolution from a CLP cell, which is likely premalignant. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Primary thyroid lymphoma: A multi-center retrospective review

BACKGROUND

Primary thyroid lymphoma (PTL) is rare and diagnosis is challenging.

METHODS

We conducted a multicenter retrospective study of patients with PTL from 1990 to 2023 to determine method of diagnosis, treatment, and outcomes.

RESULTS

The study cohort included 31 patients with PTL; all had thyroid enlargement; 21 (68 ​%) had compressive symptoms, 11 (35 ​%) had hypothyroidism and 3 had (10 ​%) B symptoms. Diagnosis was established from incisional biopsy in 8 (26 ​%), needle biopsy in 4 (13 ​%), excisional lymph node biopsy in 1 (3 ​%), and thyroidectomy specimens in 18 (58 ​%). 15 (48 ​%) patients had Hashimoto thyroiditis. Treatment included chemotherapy in 19 (61 ​%); surgery alone in 7 (23 ​%); and radiation alone or with surgery in 5 (16 ​%) patients. One (3 ​%) patient recurred, and 4 (13 ​%) patients died after a median 4.2 years.

CONCLUSION

Diagnosis of PTL was made in only 13 ​% of patients preoperatively. There may be opportunity for needle biopsy to facilitate earlier diagnosis and treatment.

Surgery is a Viable Treatment Option for Stage IE Primary Thyroid Lymphoma

BACKGROUND

Stage IE primary thyroid lymphoma (PTL) has been diagnosed in approximately half of patients with PTL; however, the optimal treatment for stage IE PTL has not yet been established.

METHODS

Stage IE PTL patients were identified from the Surveillance, Epidemiology, and End Results (SEER) database between 1998 and 2019. Thereafter, the disease-specific survival (DSS) and treatment modalities (surgery alone, surgery + radiotherapy (RT) and/or chemotherapy (CT), and RT and/or CT) of these patients were compared by Kaplan-Meier curves and log-rank test after propensity score matching (PSM). Additionally, patients with PTL from the Affiliated Sixth People's Hospital of the Shanghai Jiao Tong University and School of Medicine (Shanghai, China) between 2007 and 2022 were retrospectively analyzed as an external cohort.

RESULTS

Among the 1596 patients with PTL from the SEER database, 842 were identified as patients with stage IE PTL, with an average follow-up period of 7.8 years. Pairwise analysis after PSM revealed no significant difference between the DSS of the three treatment groups. A total of 38 patients with PTL were identified in the external cohort, with an average follow-up period of 3.4 years. Compared with the RT and/or CT group, the surgery-alone group showed no significant difference in the incidence of hypothyroidism (p = 0.161) but had significantly fewer treatment-related complications (p = 0.021), shorter treatment duration (p < 0.001), and lower treatment costs (p = 0.025).

CONCLUSIONS

The results of our study demonstrate that surgery is a viable treatment option for patients with stage IE PTL.

Primary thyroid MALT lymphoma with a probable brain secondary in a male patient: A case report

INTRODUCTION AND IMPORTANCE

Primary Mucosa-associated lymphoid tissue (MALT) lymphoma of the thyroid is a rare tumor.

PRESENTATION OF CASE

A previously well male in his 50s presented to our institution with difficulty in breathing and sleep apnea. He was diagnosed with a large retrosternal multinodular goiter with level 2 unilateral cervical lymphadenopathy. Fine needle aspiration cytology of the thyroid revealed chronic thyroiditis and the enlarged lymph node cytology was inconclusive. He underwent total thyroidectomy and level VI bilateral cervical lymph node clearance. The histology revealed an extra-nodal marginal zone lymphoma of MALT. A whole-body CT scan did not demonstrate any other primary site. The patient received 4 cycles of local radiotherapy. Subsequently, he was diagnosed with a brain tumor not amenable to surgical interventions following persistent headaches. He died shortly after due to complications of probable cerebral metastasis.

CASE DISCUSSION

MALT lymphomas of the thyroid carry a good prognosis; however, no universal guidance exists regarding the optimal therapy and follow-up.

CONCLUSION

This case report highlights the importance of early diagnosis, identification of poor prognostic factors, and patient-tailored therapy and follow-up.

Primary Thyroid Lymphoma: Clinical Factors Predicting the Possibility of Diffuse Large B-Cell Lymphoma

Aims: Among primary thyroid lymphomas (PTLs), diffuse large B-cell lymphoma (DLBCL) has a poorer prognosis than other indolent lymphomas such as mucosa-associated lymphoid tissue (MALT) or follicular lymphoma (FL). However, the clinical differences between DLBCL and indolent lymphoma remain unclear. Therefore, this retrospective study on PTL was aimed at investigating the clinical differences between DLBCL and indolent lymphomas and identifying the factors differentiating DLBCL from indolent lymphomas. Materials and Methods: Medical records of 28 patients diagnosed with PTL and treated at our institution between 2005 and 2022 were retrospectively analyzed. Data on the following clinical variables were extracted: sex, age, symptoms (pain and dysphagia), ultrasonographic appearance patterns, the presence of airway stenosis on computed tomography and laryngeal endoscopy, blood test results, disease stage, and pathological diagnosis. Results: In all, 13 patients were histologically diagnosed with DLBCL, 12 with MALT lymphoma, and 3 with FL. Significant differences in disease-specific survival rates were evident between the DLBCL and indolent lymphoma groups (68.2 vs 100%, P = .043). High lactate dehydrogenase levels (>230 U/mL) and airway stenosis were observed only in patients with DLBCL. Multivariate analysis identified that the presence of a linear echoic strand pattern and the absence of an echoic nodular pattern on ultrasound were independently associated with DLBCL (P = .0497 and .012, respectively). Conclusion: DLBCL can cause airway stenosis. The linear echogenic strand pattern and the absence of a nodular pattern should be recognized as predictive factors of DLBCL.

Feasibility of fine needle aspiration for diagnosis of b-cell lymphoma of the thyroid: a case series and review of the literature

BACKGROUND

Primary thyroid lymphoma (PTL) is a rare cancer accounting for approximately 5% of thyroid malignancies. Historically, incisional biopsy has been the gold standard for definitive diagnosis of PTL, however, the use of cell block as an adjunct to fine needle aspiration (FNA) provides a high sensitivity and specificity for diagnosis and classification.

METHODS

Three patients presented with a symptomatic enlarging thyroid mass. Patient 1 underwent incisional biopsy under general anesthesia, Patient 2 underwent core needle biopsy to avoid high risk intubation, and Patient 3 underwent fine needle aspiration alone with the use of cell block.

RESULTS

All patients were diagnosed with a fully classified non-Hodgkin's lymphoma using immunohistochemistry, flow cytometry, and fluorescence in situ hybridization (FISH) analysis.

CONCLUSIONS

FNA for diagnosis of some subtypes of PTL is feasible and preferred in cases that are particularly high risk for general anesthesia. This minimally invasive technique is safe and cost effective as it avoids expenses associated with operative intervention.

Risk factors analysis and establishment of predictive nomogram of extranodal B-cell lymphoma of mucosal-associated lymphoid tissue

PURPOSE

The role of radiation therapy in mucosa-associated lymphoid tissue (MALT) lymphoma is poorly defined. The objective of this study was to explore the factors associated with the performance of radiotherapy and to assess its prognostic impact in patients with MALT lymphoma.

PATIENTS AND METHODS

Patients with MALT lymphoma diagnosed between 1992 and 2017 were identified in the US Surveillance, Epidemiology, and End Results database (SEER). Factors associated with the delivery of radiotherapy were assessed by chi-square test. Overall survival (OS) and lymphoma-specific survival (LSS) were compared between patients with and without radiotherapy, using Cox proportional hazard regression models, in patients with early stage as well as those with advanced stage.

RESULTS

Of the 10,344 patients identified with a diagnosis of MALT lymphoma, 33.6% had received radiotherapy; this rate was 38.9% for stage I/II patients and 12.0% for stage III/IV patients, respectively. Older patients and those who already received primary surgery or chemotherapy had a significantly lower rate of receiving radiotherapy, regardless of lymphoma stage. After univariate and multivariate analysis, radiotherapy was associated with improved OS and LSS in patients with stage I/II (HR=0.71 [0.65-0.78]) and (HR=0.66 [0.59-0.74]), respectively, but not in patients with stage III/IV (HR=1.01 [0.80-1.26]) and (HR=0.93 [0.67-1.29]). The nomogram built from the significant prognostic factors associated with overall survival of stage I/II patients had a good concordance (C-index=0.749±0.002).

CONCLUSION

This cohort study shows that radiotherapy is significantly associated with a better prognosis in patients with early but not advanced MALT lymphoma. Prospective studies are needed to confirm the prognostic impact of radiotherapy in patients with MALT lymphoma.

The Distinctive Nature of Thyroid MALT Lymphomas Including IRTA1 Expression

Mucosa-associated lymphoid tissue (MALT) lymphomas often express IgM and IRTA1 with only a minority demonstrating plasmacytic differentiation. However, like primary cutaneous marginal zone lymphoproliferative disorders (PCMZLPD), thyroid MALT lymphomas (T-MALT-L) frequently show plasmacytic differentiation and IgG positivity. Whether T-MALT-L share other features with PCMZLPD, including frequent IgG4 positivity and infrequent IRTA1 expression, and how IRTA1 staining compares to that in Hashimoto thyroiditis (HT) are unknown. Therefore, the clinicopathologic features of 18 T-MALT-L were assessed, and their IRTA1 expression compared with that in 5 HT cases. All T-MALT-L cases included a B-lymphoid component. Plasmacytic differentiation was present in 15 cases and was extensive in 12. Fourteen cases were IgG+ including 2 IgG4+ (12 κ+, 2 κ-/λ-). One case was IgAλ+. Plasmacytic cells were uniformly CD19+/CD56- but CD138- in 7/15 cases. IRTA1+ cells were present in 16/16 cases, ranging from scattered cells to >50%. They were often concentrated in "MALT ball"-type lymphoepithelial lesions, perifollicular regions, and sometimes in germinal centers. IRTA1 positivity was also present in all HT cases, although it was never very extensive and often had a perifollicular distribution, occasionally with sparse aggregates and positive cells within rare thyroid follicles. Thus, T-MALT-L share some features with PCMZLPD but are more similar to noncutaneous MALT lymphomas, with prominent lymphoepithelial lesions, ubiquitous although variable IRTA1 positivity, and infrequent IgG4 positivity. Plasmacytic differentiation is also common although CD138 loss is frequent and light chain staining may be absent. IRTA1 staining may help in the differential diagnosis with HT, although there is some overlap in staining patterns.

Role of Surgery in Patients with Stage IE Primary Thyroid MALT Lymphoma Staged by a Modified Classification System: The Tokyo Classification

PURPOSES

To establish the appropriate staging system and assess the role of curative thyroidectomy alone (Surgery) vs. involved-site radiation therapy after open biopsy (OB-ISRT) in stage IE mucosa-associated lymphoid tissue (MALT) lymphoma.

METHODS

We examined the Tokyo Classification as a modified classification. This retrospective cohort study included 256 patients with thyroid MALT lymphoma; 137 underwent standard therapy (i.e., OB-ISRT) and were enrolled for the Tokyo classification. Sixty stage IE patients with the same diagnosis were examined to compare Surgery with OB-ISRT.

RESULTS

Overall survival (p = 0.0092) and relapse-free survival (0.00113) were significantly better in stage IE vs. stage IIE under the Tokyo classification. No OB-ISRT and Surgery patients died, but three OB-ISRT patients relapsed. The incidence of permanent complications was 28% in OB-ISRT (mainly dry mouth) and 0% in Surgery (p = 0.027). The number of painkiller prescription days was significantly greater in OB-ISRT (p < 0.001). During follow-up, the rate of the new appearance/change of the low-density area in the thyroid gland was significantly higher in OB-ISRT (p = 0.031).

CONCLUSIONS

The Tokyo classification allows an appropriate discrimination between stages IE and IIE MALT lymphoma. Surgery can provide a good prognosis in stage IE cases; it also avoids complications, shortens painful periods during treatment, and simplifies ultrasound follow-up.

Thyroid Mucosa-associated Lymphoid Tissue Lymphoma Presenting as Intermediate-risk Thyroid Nodule with Positive KRAS Mutation

Background

/Objective: Little is known about the epidemiology, clinical presentation, and diagnosis of thyroid mucosa-associated lymphoid tissue (MALT) lymphoma.

Case Report

We report the case of a 67-year-old woman who presented with an intermediate-risk thyroid nodule 8 years after diagnosis of hypothyroidism due to Hashimoto's. She was found to have a well-circumscribed hypoechoic 2.6-cm right-sided thyroid nodule lobe, which was biopsied and returned atypia of undetermined significance with positive KRAS mutation on the Thyroseq V3 Genomic Classifier. She subsequently underwent right thyroid lobectomy and was found to have thyroid MALT lymphoma on histopathological sections. After the surgery, she was referred to oncology for further management of the thyroid MALT lymphoma. A positron emission tomography/computed tomography scan was performed for complete staging and revealed diffuse fluorodeoxyglucose uptake in the residual left thyroid lobe without evidence of extrathyroidal involvement. Her case was discussed in a multidisciplinary fashion among oncology, endocrine surgery, and endocrinology. Given the positron emission tomography scan findings, she ultimately underwent completion thyroidectomy 4 months after the initial surgery to rule out residual disease. The patient tolerated the operation well without complication.

Discussion

Our report adds to the literature that Hashimoto's thyroiditis may be a risk factor of thyroid MALT lymphoma. Localized thyroid MALT lymphoma may be managed with total thyroidectomy.

Conclusion

We report a patient with localized thyroid MALT lymphoma who presented with an intermediate-risk nodule with positive KRAS mutation and was treated with total thyroidectomy.

Multimodal Sonographic Appearance and Survival Outcomes of 69 Cases of Primary Thyroid Lymphoma Over 10 Years

OBJECTIVES

To investigate ultrasound appearance and the survival outcomes for patients with primary thyroid lymphoma (PTL).

METHODS

Ultrasonic images and clinical characteristics from pathologically confirmed 69 PTL patients (2008-2019) were retrospectively analyzed. The clinical characteristics, ultrasonic characters, and prognostic factors were analyzed. Survival curves were plotted using the Kaplan-Meier method. Univariate and multivariate analyses were performed.

RESULTS

Of the 69 study patients, 23 were indolent PTL and 46 were aggressive PTL. Age (>70 years old) and elevated lactate dehydrogenase levels were statistically different clinical features between aggressive and indolent PTL. From ultrasonic images, 34 cases were nodular, 11 diffuse, and 24 mixed pattern. Mixed types displayed high invasiveness (45.7%) while diffuse types displayed higher inertness (39.1%), with statistically significant differences (P = .000). Invaded thyroid capsule and increased chaotic vascularity also showed significant differences between aggressive and indolent PTL. We also observed statistical difference in overall survival rates between aggressive and indolent PTL (P = .032). Single factor K-M analyses showed that age >70 years, aggressive pathology, and Ki67 >30% were positively correlated with the risk of poor PTL survival (P < .05).

CONCLUSIONS

Multimodal ultrasound provides accurate ultrasonographic information and facilitates PTL invasiveness diagnostics for improved clinical treatment. In addition, PTL patients aged >70 years, with aggressive pathology, and Ki67 >30% were more likely to have a poor survival outcome.

Diffuse Large B-Cell Lymphoma of Thyroid: A Case Report and Review of Literature

Primary thyroid lymphoma is a rare malignancy, accounting for 1-2% of extra-nodal lymphomas and 1-5% of thyroid malignancies. Diffuse large B-cell lymphoma is the most common type of primary thyroid lymphoma. It usually presents with a rapidly enlarging neck mass with cervical lymphadenopathy. Though rare, early diagnosis of this condition is important because its management is quite different from the treatment of other thyroid neoplasms. It is usually treated by chemotherapy with or without radiotherapy. We present the case of a 43 years old male who presented with thyroid swelling which on histopathology and subsequent immunohistochemistry was confirmed as diffuse large B-cell lymphoma of the thyroid.

The Risk of Developing Lymphoma among Autoimmune Thyroid Disorder Patients: A Cross-Section Study

Background

Graves' disease (GD) and Hashimoto's thyroiditis (HT) are the most common types of autoimmune thyroid diseases (AITD), and both are characterized by the infiltration of lymphocytes into the thyroid gland. Moreover, autoimmune diseases like HT have a higher risk of developing lymphoma. This study is aimed at assessing the prevalence and association of lymphoma in patients with AITD.

Methods

This cross-sectional study was conducted in King Abdulaziz Medical City, Jeddah, Saudi Arabia. Data were gathered from the medical records of patients aged 18 years or older who developed AITD. A total number of 140 medical records were collected, and 72 patients were included after applying in exclusion criteria. Data on the subtype, clinical-stage, treatment modality, patient status, remission, and relapse were collected for patients who developed lymphoma.

Results

Among 72 patients who developed AITD, HT was diagnosed in 58 (80.6%) patients and GD in 14 (19.4%). Five (7%) patients were diagnosed with lymphoma all of whom had a history of HT. The subtypes of lymphoma were diffuse large B-cell lymphoma (DLBCL 3; 4.2%), follicular lymphoma 1 (1.4%), and Hodgkin's lymphoma 1 (1.4%).

Conclusion

The prevalence of PTL in patients with AITD, specifically HT, was 7%. Most patients developed NHL, with DLBCL being the most common subtype. The onset of lymphoma in this study was lower than reported in the literature. All patients with PTL had HT in their backgrounds. Further national studies are warranted to explore the relationship between the two diseases to provide more insight into the comprehension of this association.

The Relationship Between Primary Thyroid Lymphoma and Various Types of Thyroid Autoimmunity: A Retrospective Cohort Study of 498 Cases, Including 9 Cases with Graves' Disease

Background: Primary thyroid lymphoma (PTL) is known to develop mostly in patients with Hashimoto's thyroiditis (HT), and it is rare for it to develop in patients with Graves' disease (GD). The objective of this study was to investigate the clinical features, pathological findings, and long-term outcomes of PTL patients, grouped according to the presence of GD, HT, or no autoimmune thyroid disease (AITDs). The GD group was of major interest due to limited knowledge of the relationship with PTL. Methods: In this single-center retrospective cohort study, we reviewed the medical records of all patients diagnosed with PTL between August 1979 and October 2021, and we characterized the patients according to the presence of HT, GD, or no AITDs. Pathological specimens were classified according to the World Health Organization classification. Staging was performed in accordance with the Ann Arbor classification. Results: During the 42-year period, 498 participants were diagnosed with PTL. The median age was 68 (interquartile range 61-76) years, and 221 patients were stage IE, whereas the remaining 277 patients were stage IIE. Of the PTL patients, 431 (86.6%) were diagnosed with HT, 9 (1.8%) were diagnosed with GD, and 58 (11.6%) did not have AITDs. All nine patients with GD were positive for anti-thyroglobulin antibody and/or anti-thyroid peroxidase antibody. All patients with GD were treated with anti-thyroid medication. There were no significant differences in the proportions of each subtype of PTL between the PTL patients with GD and all subjects with PTL (p = 0.51), PTL patients with HT (p = 0.51), or PTL patients without AITDs (p = 0.48). The median follow-up time was 6.2 (interquartile range 3.0-10.7) years after the diagnosis of PTL. The Kaplan-Meier curve analyses showed no significant differences in overall survival and event-free survival between PTL patients with GD and those with HT (p = 0.37), or between PTL patients with GD and those without AITDs (p = 0.43). Conclusions: The PTL was observed with HT in a majority of cases, and rarely with GD (1.8%). The proportions of each pathological subtype of PTL and the prognosis of PTL were not different between the patients with GD and those with HT or those without AITDs.

Characterization of Second Primary Malignancies in Mucosa-Associated Lymphoid Tissue Lymphomas: A SEER Database Interrogation

INTRODUCTION

Second primary malignancies (SPMs) are long-term complications in cancer survivors. Mucosa-associated lymphoid tissue (MALT) lymphomas are indolent extra-nodal marginal zone lymphomas, the majority of which typically have long-term survival. In this study, we investigated the incidence and pattern of SPMs in adult patients diagnosed with MALT lymphomas between January 2000 and December 2016.

METHODS

Using the SEER-18 database and multiple primary standardized incidence ratio (MP-SIR) session of SEER stat software for statistical analysis, we assessed SPMs in MALT lymphomas.

RESULTS

During this time, a total of 12,500 cases of MALT lymphomas were diagnosed, of which 1466 patients developed 1626 SPMs (O/E ratio: 1.48, 95% CI:1.41-1.55, P<.001). The median latency period for development of SPMs was 54 months (range 6-201 months). Secondary non-Hodgkin lymphomas, as defined by SEER as distinct from the primary lymphoma, was the most common SPM with 299 cases, followed by lung cancer (O/E ratio: 6.15, 95% CI:5.47-6.89, P<.0001). There were 898 SPMs that developed between 6- 59 months (O/E ratio: 1.47, 95% CI:1.37-1.57, P<.0001) and 728 after 60 months latency (O/E ratio: 1.5, 95% CI:1.39-1.61, P<.0001) after diagnosis of the primary MALT lymphomas. An increased incidence of both solid and hematologic cancers occurred in patients as early as 6 months after diagnosis of MALT lymphoma.

CONCLUSION

These findings indicate that despite the indolent nature of most MALT lymphomas, there is an increased risk for SPMs warranting long-term follow up.

Comparison of the clinical characteristics of primary thyroid lymphoma and diffuse sclerosing variant of papillary thyroid carcinoma

OBJECTIVE

Both primary thyroid lymphoma (PTL) and diffuse sclerosing variant of papillary thyroid carcinoma (DSVPTC) are two rare malignant tumours with different therapies and prognoses. This study compared their clinical features.

METHODS

From a retrospective review of the pathologic database at our institute between January 2015 and August 2020, 52 PTL patients and 40 DSVPTC patients were included. Demographic, clinical, laboratory and ultrasound data were extracted from electronic medical records. Statistical analyses were performed using GraphPad Prism 5.0.

RESULTS

Both PTL and DSVPTC were more likely to occur in women (83.7 and 67.5%, respectively), but DSVPTC patients were younger (median age: 36 vs 64.5), had fewer compressive symptoms, and more frequently had neck lymph node metastasis than PTL patients. The prevalence of Hashimoto's thyroiditis (HT) and hypothyroidism was significantly higher in PTL patients than in DSVPTC patients (31% vs 17.5%). Hyperthyroidism could only be found in DSVPTC patients, which accounted for 7.5%. Heterogeneous echogenicity and irregular edges were frequently observed in both PTL and DSVPTC. However, compared with PTL, DSVPTC exhibited smaller lesion sizes, higher frequencies of diffuse sonographic patterns and calcification and lower frequencies of hypoechoic features and internal blood flow signal. The overall survival rate with PTL was 77.23%, which was lower than that with DSVPTC (90.91%), but this difference was not significant (P = 0.096).

CONCLUSION

Clinical characteristics such as age, compression symptoms, and sonographic features such as a large mass with heterogeneous echogenicity, hypoechoic, irregular edges, and calcification are helpful for impression diagnosis of PTL and DSVPTC before surgery.

Thyroid MALT lymphoma: self-harm to gain potential T-cell help

The development of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) is driven by chronic inflammatory responses and acquired genetic changes. To investigate its genetic bases, we performed targeted sequencing of 93 genes in 131 MALT lymphomas including 76 from the thyroid. We found frequent deleterious mutations of TET2 (86%), CD274 (53%), TNFRSF14 (53%), and TNFAIP3 (30%) in thyroid MALT lymphoma. CD274 was also frequently deleted, together with mutation seen in 68% of cases. There was a significant association between CD274 mutation/deletion and TNFRSF14 mutation (p = 0.001). CD274 (PD-L1) and TNFRSF14 are ligands for the co-inhibitory receptor PD1 and BTLA on T-helper cells, respectively, their inactivation may free T-cell activities, promoting their help to malignant B-cells. In support of this, both the proportion of activated T-cells (CD4+CD69+/CD4+) within the proximity of malignant B-cells, and the level of transformed blasts were significantly higher in cases with CD274/TNFRSF14 genetic abnormalities than those without these changes. Both CD274 and TNFRSF14 genetic changes were significantly associated with Hashimoto’s thyroiditis (p = 0.01, p = 0.04, respectively), and CD274 mutation/deletion additionally associated with increased erythrocyte sedimentation rate (p = 0.0001). In conclusion, CD274/TNFRSF14 inactivation in thyroid MALT lymphoma B-cells may deregulate their interaction with T-cells, promoting co-stimulations and impairing peripheral tolerance.

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

AIM

Primary thyroid lymphoma (PTL) is a rare malignant disease. Its prognosis depends on early diagnosis. The role of fine-needle aspiration (FNA), including smear cytology, cell block (CB) techniques, and immunohistochemistry (IHC) sections in the diagnosis of PTL is still unclear. Here we reported 19 cases of PTL and literature review to evaluate the diagnostic accuracy for lymphoma by cytology.

METHODS

Our study retrospectively reviewed 19 patients diagnosed with PTL at the affiliated hospital of Southwest Medical University in China from June 2011 to May 2019. According to the Bethesda system for reporting thyroid cytopathology, the CB sections were evaluated for the presence of single tumor cells. IHC was performed on CB.

RESULTS

The diagnostic accuracy for PTL of FNA, CB with smears, and the joint application of the three methods (FNA + CB + IHC) of our study with 19 cases was 68.4% (13/19), 83.3% (15/18), and 100% (17/17), respectively.

CONCLUSION

The present study demonstrates that FNA has low sensitivity in diagnosing PTL, but the joint application of FNA, CB, and IHC might provide high diagnostic accuracy for lymphoma and should be applied in all cases where the clinical suspicion is high regardless of the FNA findings.

Thyroid lymphoproliferative lesions in Asia

Primary thyroid lymphomas (PTLs) are rare and most commonly present as rapidly enlarging thyroid mass causing obstructive symptoms. Due to worldwide differences in clinical practices related to thyroid malignancy, this review was conducted to compare the clinicopathological and diagnostic modalities related to PTL and their similarities and differences between the Asian and Western countries. Using the search engine PubMed, published data on thyroid lymphomas was collected and reviewed. A total of 18 Asian and 22 Western studies were included. Most of PTLs were B-cell Non-Hodgkin lymphomas (NHL). While mucosa-associated lymphoid tissue (MALT) lymphoma was the commonest (41.1%) among Asians, diffuse large B cell lymphoma (DLBCL) (71.9%) predominated in the Western population. Some rare subtypes of PTL were also identified. Majority of all patients in Asian as well as Western studies presented with early stage (stage I/II) disease. Interestingly, when compared with Asian patients, a larger proportion of patients from the West presented with higher stage (stage III/IV) disease (12.2% vs. 3%). Ultrasonography (USG) and fine needle aspiration cytology (FNAC) in addition to histological examination usually by core needle biopsy and in some by open procedures were used for the diagnosis of PTL in both the cohorts. The various ancillary techniques used were immunocytochemistry (ICC), flowcytometry (FC), immunohistochemistry (IHC), and molecular testing. The use of ancillary techniques for PTL diagnosis was more common in the West compared to Asia and markedly increased the sensitivity of cytology to diagnose PTL. Treatment and prognosis largely depend upon the subtype of PTL and stage at presentation. To conclude, from the available published literature, there is an apparent difference between Asian and Western cohorts in the histological type and stage of presentation of PTL, but the results may be affected by publication and selection bias. Also, advanced ancillary techniques are more commonly adopted in the West.

t(3;14)(p14.1;q32)/FOXP1-IGH translocation in thyroid extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma)

OBJECTIVES

MALT lymphoma occurs in various organs and has several characteristic genetic aberrations. Thyroid MALT lymphoma has been reported to include t(3;14)(p14.1;q32)/FOXP1-IGH as a specific genetic aberration, but the number of studies is limited.

METHOD AND RESULTS

We examined 86 thyroid lymphoma cases using fluorescence in situ hybridization (FISH) for the detection of t(3;14)/FOXP1-IGH in formalin fixed paraffin-embedded tissue (FFPE). Histopathological diagnoses of the analyzed specimen were as follows: thyroid MALT lymphoma (n = 59), DLBCL (n = 23), follicular lymphoma (n = 4), and benign lesions (n = 14) included Hashimoto's thyroiditis (n = 13) and other (n = 1). Of the 100 analyzed cases, thirty-six (36 %) thyroid lymphoma cases were positive for t(3;14)/FOXP1-IGH. Thirty-three (55.9 %) of the 59 MALT lymphoma cases were positive for t(3;14)/FOXP1-IGH. Three (13.0 %) of the 23 DLBCL cases were positive for t(3;14)/FOXP1-IGH. All 4 follicular lymphomas examined were negative for t(3;14)/FOXP1-IGH. None of the benign cases was positive for t(3;14)/FOXP1-IGH, including Hashimoto's thyroiditis (0/13) and benign tissue (0/1).

CONCLUSIONS

Our study found that t(3;14)/FOXP1-IGH was frequently found in thyroid MALT lymphoma. A detection of t(3;14)/FOXP1-IGH is extremely useful for the differential diagnosis between primary MALT lymphoma of the thyroid and other thyroid disorders.

Clinical features associated with high pathological grade in primary thyroid lymphoma

This study aimed to identify clinical features associated with high pathological grade (HG) in primary thyroid lymphoma (PTL), through a systematic review and meta-analysis. Electronic databases were searched for studies assessing PTL. Extracted data were age, sex, lymph node involvement, symptoms, lymphocytic thyroiditis, serum tumor markers; the association with HG was assessed by using odds ratio (OR), with a significant p-value<0.05. Twenty-four studies with 1916 PTLs were included. HG was significantly associated with age≤55 (OR = 0.54; p < 0.0001); female sex (OR = 1.31; p = 0.02), lymph node involvement (OR = 2.23; p < 0.00001), compressive symptoms (OR = 2.61; p < 0.0001), absence of lymphocytic thyroiditis (OR = 0.45; p = 0.0002), and increased LDH levels (OR = 4.90; p < 0.00001), but not with age>60 (OR = 0.74; p = 0.24), age>70 (OR = 1.16; p = 0.66), and B symptoms (OR = 1.30; p = 0.54). In conclusion, Age≤55, female sex, lymph node involvement, compressive symptoms and absence of lymphocytic thyroiditis may be predictive factors for HG in PTL. On the other hand, B symptoms does not seem to be associated with pathological grade.

Hashimoto Thyroiditis in Primary Thyroid Non-Hodgkin Lymphoma

OBJECTIVES

To assess the prevalence of Hashimoto thyroiditis (HT) in primary thyroid lymphoma (PTL) and whether it differs between mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B-cell lymphoma (DLBCL).

METHODS

Electronic databases were searched for studies assessing HT prevalence in PTL, based on antithyroid antibodies, clinical history, or pathology. Pooled prevalence of HT and its association with histotype (MALT or DLBCL) were calculated.

RESULTS

Thirty-eight studies with 1,346 PTLs were included. Pooled prevalence results were 78.9% (any HT evidence), 65.3% (antithyroid antibodies), 41.7% (clinical history), and 64% (pathology). HT prevalence was significantly higher in MALT lymphoma than in DLBCL (P = .007) and in mixed DLBCL/MALT than in pure DLBCL (P = .002).

CONCLUSIONS

Overall, 78.9% of patients with PTL have any HT evidence, but only half of these had been clinically followed. The difference in HT prevalence suggests that a subset of DLBCL may not derive from MALT lymphoma.

Mucosa-Associated Lymphoid Tissue Lymphoma of the Thyroid Gland: A Systematic Review of the Literature

OBJECTIVE

Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type of the thyroid gland is a rare indolent malignant disease encountered in approximately 0.5% of patients with Hashimoto thyroiditis (HT). The purpose of the present systematic review was to accumulate the current evidence in the field.

STUDY DESIGN

We searched the Medline, Scopus, EMBASE, ClinicalTrials.gov, and Cochrane Central Register of Controlled Trials CENTRAL databases from inception to May 2018. Statistical analysis was performed with SPSS version 22.0.

RESULTS

Fourteen case series and 20 case reports were finally included in the present systematic review. Analysis of the patient data included in the published case reports suggested that the age at diagnosis of MALT lymphoma does no differ among males and females (64 [52.5-73] vs. 67 [60.5-72] years, p = 0.442). HT was detected in 60% of patients, whereas coexisting carcinoma was evident in 17% of cases. The incidence of HT and thyroid cancer was comparable among males and females (p = 0.474 and p > 0.999, respectively). Among all patients included in the present systematic review there were two disease relapses and two deaths attributed to the disease.

CONCLUSION

MALT lymphoma of the thyroid gland is a rare malignancy with an indolent course. The scarce data available in the literature preclude safe conclusions concerning the mode of treatment and follow-up of these patients. However, the combination of minimally invasive surgery and adjuvant therapy seems feasible. Moreover, an extended follow-up period is recommended.

Clinicopathological characteristics and prognostic factors for primary thyroid lymphoma: report on 28 Chinese patients and results of a population-based study

Objectives

Few studies on prognostic indicators for primary thyroid lymphoma (PTL) have been presented due to the uncommon nature of the tumor. This is the first study to explore the independent prognostic factors in the 2 PTL subtypes.

Methods

We retrospectively reviewed 1,653 cases of PTL. The cases comprised 28 Chinese patients from a local cohort and 1,625 patients from the Surveillance, Epidemiology, and End Results database from 1973 to 2013. Statistical analysis was performed to determine the demographics and prognostic factors of PTL patients.

Results

The disease-specific survival (DSS) and prognostic indicators were significantly different between patients with extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) and patients with diffuse large B-cell lymphoma (DLBCL). Patients with MALT lymphoma were younger (P=0.011) and had lower clinical stage (P=0.014) compared to patients with DLBCL. Cox regression analysis revealed that age, treatment modalities employed, clinical stage, and number of other types of cancer were independent prognostic factors for DLBCL patients.

Conclusion

PTL demonstrates specific clinical features and is associated with a relatively good prognosis. Older age is associated with poor DSS in both MALT patients and DLBCL patients. Additionally, combination of different treatment modalities is associated with improved DSS in DLBCL patients.