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

Fine Needle Aspiration of CD20-Negative Diffuse Large B Cell Lymphoma Presenting as an Anterior Neck Mass

Aggressive lymphoma of the neck presenting with life‐threatening airway compromise requires quick diagnosis, which can be rendered with fine needle aspiration cytology. In atypical cases, using multiple B cell markers can be helpful to avoid misdiagnosis.

Extranodal marginal zone lymphoma of the larynx: A case report and scoping review

BACKGROUND

This scoping review aims to review cases of extranodal marginal zone lymphoma (MZL) of the larynx to establish best management practices for this rare clinical entity.

METHODS

In this paper, we report a case of laryngeal MZL, in accordance with CARE guidelines. We then performed a scoping review according to PRISMA-ScR criteria of published cases of MZL involving the larynx. The following data were collected for each case: age, sex, size, location(s) involved, stage, treatment, follow-up, and recurrence duration.

RESULTS

Sixty-six patients with laryngeal MZL, first reported in 1990, were identified. Characterized by its low-grade histological appearance and indolent course, laryngeal MZL is generally confined to the larynx and has an excellent prognosis with radiation used as first-line therapy.

CONCLUSIONS

It is imperative for clinicians to consider lymphoma in the differential diagnosis of a laryngeal tumor from any subsite, as certain pathologies may carry high risks of metastasis.

Marginal zone lymphoma of extranodal sites: A review with an emphasis on diagnostic pitfalls and differential diagnosis with reactive conditions

Marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) represents 8% of all B-cell lymphomas and it is the most common small B-cell lymphoma arising at extranodal sites. The gold-standard test to establish a diagnosis of MALT lymphoma remains histopathologic analysis with the aid of immunohistochemistry (IHC) and/or flow cytometry immunophenotypic analysis. MALT lymphoma represents a progression from a persistent chronic inflammatory process, and therefore distinguishing MALT lymphoma from chronic inflammation by histopathology may be challenging in some cases. Despite recent trends to consider IGH rearrangement/clonality as a confirmatory diagnostic test of MALT lymphoma, this method is far from ideal for this purpose since a positive or a negative result does not necessarily confirm or exclude that a process is lymphoma or reactive. This test must be correlated with the morphologic findings. Moreover, MALT lymphoma may arise in association with underlying autoimmune conditions where clonal lymphoid populations are not uncommonly detected. Therefore, we believe that an integrated approach including detailed morphologic review in combination with IHC and/or flow cytometry is best to establish a diagnosis of MALT lymphoma in most cases. We present helpful morphologic tips to avoid potential diagnostic pitfalls at some of the most common extranodal sites, including the stomach, ocular adnexa/conjunctiva, salivary gland, lung, thymus, breast, thyroid, small and large intestine and the dura. The differential diagnosis of MALT lymphoma with IgG4-related disease is also discussed.

Marginal zone lymphomas: a consensus practice statement from the Australasian Lymphoma Alliance

Marginal zone lymphomas (MZLs) are a rare, indolent group of non-Hodgkin lymphomas with different diagnostic, genetic and clinical features and therapeutic implications. The most common is extranodal MZL of mucosa-associated lymphoid tissue, followed by splenic MZL and nodal MZL. Patients with MZL generally have good outcomes with long survival rates but frequently have a relapsing/remitting course requiring several lines of therapy. The heterogeneous presentation and relapsing course present the clinician with several diagnostic and therapeutic challenges. This position statement presents evidence-based recommendations in the setting of Australia and New Zealand.

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.

Marginal zone lymphoma: 2023 update on diagnosis and management

DISEASE OVERVIEW

Marginal zone lymphomas (MZL) are collectively the second most common type of indolent lymphoma.

DIAGNOSIS

Three subtypes of MZL are recognized: splenic, extranodal, and nodal. The diagnosis is secured following biopsy of an involved nodal or extranodal site demonstrating a clonal B-cell infiltrate with CD5 and CD10 negative immunophenotype most common. Some cases will features IgM paraprotein, but MYD88 L256P mutations are less frequent than in Waldenstrom macroglobulinemia. Prognostication Several prognostic models have been developed, including the MALT-IPI and the MZL-IPI. The latter is broadly applicable across MZL subtypes and incorporates elevated serum LDH, anemia, lymphopenia, thrombocytopenia and nodal or disseminated subtypes as independent predictors of outcome.

TREATMENT

We discuss suggested approach to therapy for both early and advanced-stage disease, with reference to chemo-immunotherapy, radiotherapy, and emerging treatments in relapsed/refractory disease such as BTK inhibitors.

Mucosa-associated lymphoid tissue lymphoma (MALT lymphoma) in the thyroid mimicking a painless subacute (De Quervain's) thyroiditis on presentation, fine needle aspiration and cytology, and ultrasound findings: A rare case report

INTRODUCTION

We report a rare case of mucosa-associated lymphoid tissue lymphoma (MALT lymphoma) in the thyroid mimicking painless subacute (De Quervain's) thyroiditis.

PRESENTATION OF CASE

Patient with history of hypothyroidism presented with huge non-tender goiter, compression symptoms and choking, no lymphadenopathy. Ultrasound (US) showed large thyroid lobes. There was a small hypoechoic nodule, and nonspecific lymphadenopathy. Fine needle aspiration/cytology (FNAC) of right thyroid nodule showed scant follicular cells, abundant polymorphic lympocytes, epithelioid histiocytes, and tingible body macrophages, suggestive of De Quervain's (granulomatous) thyroiditis. Total thyroidectomy was decided due to compression symptoms and huge goiter.

DISCUSSION

Intraoperative, thyroid was huge with no adhesions to the strap muscles/trachea. Total thyroidectomy with lymph node biopsy was undertaken. There were no complications. Postoperatively, the patient's condition was stable, breathing normally, and neck wound was clean. PTH was 11 pg/mL and calcium was 2.16 mmol/L, suggesting impending transient hypocalcemia. Histopathology showed lymphoepithelial lesions as clusters of lymphocytes within the thyroid follicles epithelium (MALT Balls). Immunohistochemical staining showed that the neoplastic lymphocytes were B cells and stained positive with B-cell markers CD20 and PAX5, but were negative for Cyclin D1 and for T cell markers CD3, CD5 and CD43. The patient was discussed at the lymphoma MDT meeting and the decision was to start the patient on radiotherapy which the patient received.

CONCLUSION

Thyroid MALT lymphoma can mimic painless subacute thyroiditis. The triad of a large swelling of non-tender goiter with compression symptoms during a short period; FNAC findings suggestive of thyroiditis; and US showing enlarged thyroid lobes might cause confusion to the unsuspecting practitioner. Histopathology after excision provides definitive diagnosis.

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.

Management of Marginal Zone Lymphoma: A Canadian Perspective

Marginal zone lymphomas (MZL) are a rare, heterogenous group of lymphomas, accounting for 5-17% of indolent non-Hodgkin lymphomas in the western world. They can be further divided into three subtypes: extranodal MZL, splenic MZL, and nodal MZL. These subtypes differ in clinical presentation and behavior, which influences how they are managed. There is currently no standard of care for the treatment of MZL, owing to the difficulty in conducting phase 3 randomized trials in MZL, and the fact that there are limited data on the efficacy of therapy in individual subtypes. Treatment practices are thus largely borrowed from other indolent lymphomas and are based on patient and disease characteristics, as well as access to therapy. This review summarizes the Canadian treatment landscape for MZL and how these therapies may be sequenced in practice.

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.

Primary hepatic mucosa-associated lymphoid tissue lymphoma with HP and previous HBV infection: A case report and literature review

Primary hepatic mucosa-associated lymphoid tissue (MALT) lymphoma is a relatively rare disease with low malignancy, and its aetiology is unclear. A 65-year-old man presented with abdominal pain. Hepatitis virus examination revealed a previous hepatitis B virus (HBV) infection, and a carbon-13 urea breath test result was positive for the patient. Abdominal contrast-enhanced computed tomography revealed a patch of abnormal density in the right posterior lobe of the liver. The patient underwent VI segment hepatectomy and was pathologically diagnosed with hepatic MALT lymphoma. After the operation, he received quadruple anti-Helicobacter pylori (HP) therapy and refused other treatments. He has been followed up by telephone for 20 months after discharge and is now in a stable condition. In this study, we counted 105 cases of hepatic MALT lymphomas reported in English or Chinese since 1995 and summarised the clinical characteristics and concomitant diseases in this condition. Based on the literature review, we speculated that chronic infectious diseases, especially viral infections (including hepatitis C virus (HCV) and HBV) and HP infection, are associated with the pathogenesis of primary hepatic MALT lymphoma. In addition, autoimmune diseases might also play a role in this condition.

Cancer incidence in primary Sjögren's syndrome: Data from the French hospitalization database

The relationship between cancer and primary Sjögren's syndrome (pSS) is uncertain. While the increased risk of hematological malignancies is well-known, data on the comparative incidence of solid neoplasms is conflicting. This study aimed to explore the associations between cancer and pSS. This nationwide population-based retrospective study from the French health insurance database (PMSI) evaluated patients hospitalized with new-onset pSS from 2011 to 2018 against age- and sex-matched hospitalized controls (1:10). The incidence of hematological malignancies and solid neoplasms was compared between the two groups. Mortality and multiple cancer incidence were also evaluated. Adjusted Hazard Ratios (aHR) calculations included confounding factors, such as low socioeconomic status. Among 25,661 hospitalized patients with pSS versus 252,543 matched patients (median follow-up of 3.96 years), we observed a higher incidence rate of lymphomas (aHR, 1.97 [95% CI, 1.59-2.43]), Waldenström macroglobulinemia (aHR, 10.8 [6.5-18.0]), and leukemia (aHR, 1.61 [1.1-2.4]). Thyroid cancer incidence was higher (aHR, 1.7 [1.1-2.8]), whereas bladder and breast cancer incidences were lower (aHR, 0.58 [0.37-0.89] and 0.60 [0.49-0.74], respectively). pSS patients with breast cancer exhibited a lower mortality rate. A limitation was that the database only encompasses hospitalized patients, and immunological and histological details are not listed. We confirmed the increased risk of hematological malignancies and thyroid cancers among patients with pSS. The lower risk of breast cancer suggests a role of hormonal factors and raises questions of the concept of immune surveillance within breast tissue. Epidemiological and translational studies are required to elucidate the relationships between pSS and cancer.

Characterization of molecular genetics and clinicopathology in thymic MALT lymphoma

Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) lymphoma is a type of low-grade malignant B-cell lymphoma. The aim of this study was to investigate the clinicopathological characteristics of thymic MALT lymphoma. We analyzed the clinical, morphological, immunophenotypical, cytogenetic, and molecular characteristics of 11 cases of thymic MALT lymphoma. The relevant literature was also reviewed. The median age of the 11 patients was 50 (range: 33-60). There was a female predominance with a female-to-male ratio of 10:1. Three patients presented with Sjögren syndrome, autoimmune thrombocytopenia purpura, and type B1 thymoma, respectively. Microscopically, thymic MALT lymphoma was characterized by epithelium-lined cysts that were surrounded by small lymphocytes, centrocyte-like cells, and monocytoid B-cells. Plasmacytic differentiation was observed in two cases. The tumor cells expressed CD20, CD79α, and BCL2. Clonal immunoglobulin genes were detected in all 8 examined cases. Fluorescence in situ hybridization (FISH) for 18q21 was performed in 7 cases, and no translocations involving 18q21 were found. Targeted gene sequencing was performed in five cases with available DNA samples, and TNFAIP3, CARD11, IGLL5, and CCND3 mutations were identified. Thymic MALT lymphoma is a rare type of B cell malignancy with a female predominance and excellent clinical outcomes. Molecular aberrations involving the NF-κB pathway are frequent in thymic MALT lymphoma, suggesting that dysregulation of the NF-κB pathway is an important mechanism underlying the pathogenesis of thymic MALT lymphoma.