HLA associations, microsatellite instability and epigenetic changes in thyroid lymphoma in Chinese

Clinicopathologic features of conjunctival MALT lymphomas refractory to radiation therapy

OBJECTIVE

Clinicopathologic features of patients with limited-stage mucosa-associated lymphoid tissue (MALT) lymphoma refractory to radiotherapy have not been fully elucidated. This study aimed to elucidate clinicopathologic features of localized conjunctival MALT lymphoma concerning radiosensitivity by analyzing cell proliferation and expression of mismatch repair proteins.

METHODS

We enrolled 26 patients with localized conjunctival MALT lymphoma treated with radiotherapy from November 2007 to March 2020. Monoclonal immunoglobulin H gene rearrangement was tested in addition to histopathologic evaluation. Thirty-six specimens were immunostained with antibodies to Ki-67 and MutL protein homologue 1 (MLH1), MutS protein homologue 2 (MSH2), and MutS protein homologue 6 (MSH6). Positive rates under a high-power field at a hot spot were counted manually.

RESULTS

After radiotherapy, 21 patients showed clinical disappearance of the tumour without recurrence (effective group). Three patients showed temporary disappearance of the tumour, which later recurred (relapse group). Two patients did not show disappearance of the tumour (ineffective group). The 2 ineffective patients were young, had bilateral lesions, and received x-ray beam therapy. The mean positive rates of Ki-67, MLH1, MSH2, and MSH6 were higher in tumours with complete remission (CR) than in those without CR (23.4% ± 4.0% and 18.7& ± 4.7%, 14.7% ± 2.3% and 7.1% ± 3.7%, 23.9% ± 4.7% and 14.4% ± 5.2%, and 11.5% ± 3.2% and 5.4% ± 2.2%; p > 0.05 for each, respectively).

CONCLUSIONS

A few patients could not achieve CR following radiotherapy, whereas there were no significant differences in proliferation activity and mismatch repair proteins between tumours with and without CR.

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.

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.

Identification of primary thyroid lymphoma with medical imaging: A case report and review of the literature

Primary thyroid lymphoma (PTL) is a rare thyroid malignancy. Clinical diagnosis of PTL may not be easily established based on imaging studies, as the imaging features of PTL are similar to those of lymphocytic thyroiditis and primary thyroid cancer. The present study describes the case of a patient who was confirmed to have PTL by intra-operative pathological diagnosis. On color Doppler ultrasound, the PTL was shown as a significantly enlarged thyroid with reduced gland echoes. Color Doppler flow imaging showed increased blood flow. By computed tomography, the thyroid was revealed to be enlarged with reduced tissue density, particularly in the left lobe and the isthmus. In addition, calcified spots and swollen lymph nodes were evident. The clinical history of the patient was obtained and the imaging results were retrospectively analyzed. The imaging features of PTL were investigated through reviewing the literature. PTL exhibits specific features on medical imaging that aid in distinguishing it from other thyroid diseases. PTL exhibits specific features on medical imaging that aid in distinguishing PTL from other thyroid diseases, which may aid the support for clinical diagnosis and improve the clinical accuracy.

Role of p53 family members p73 and p63 in human hematological malignancies

p53, mutated in over half of human cancers and about 13% of all hematological malignancies, maintains genomic integrity and triggers cellular senescence and apoptosis of damaged cells. In contrast to p53, the homologs p73 and p63 play critical roles in development of the central nervous system and skin/limbs, respectively. Moreover, dependent on the context they can exert tumor suppressor activities that cooperate with p53. Unlike p53, p73 and p63 are rarely mutated in cancers. Instead, up-regulation of the anti-apoptotic dominant-negative ΔNp73 and ΔNp63 isoforms is the most frequent abnormality in solid cancers. In hematological malignancies the most frequent p73 defect is promoter methylation and loss of expression, associated with unfavorable clinical outcomes. This suggests an essential tumor suppressor role of p73 in blood cells, also supported by genetic mouse models. Many therapeutic approaches aiming to restore p73 activity are currently being investigated. In contrast, the most frequent p63 abnormality is protein overexpression, associated with higher disease grade and poorer prognosis. Surprisingly, although available data are still scarce, the emerging picture is up-regulation of transactivation-competent TAp63 isoforms, suggesting a tumor-promoting role in this context.

Primary thyroid lymphoma: a review of recent developments in diagnosis and histology-driven treatment

PURPOSE OF REVIEW

Primary thyroid lymphoma (PTL) is a rare but clinically important malignancy of the thyroid. This article reviews the diagnosis, histologic subtypes, pathogenesis, and treatment of PTL, with the objective of optimizing diagnosis and management of the disease.

RECENT FINDINGS

Recent studies have shed light on the clinicopathologic features of the histologic subtypes of PTL. Analysis of the pathogenesis of PTL indicates that both antigenic stimulation in the setting of Hashimoto's thyroiditis and aberrant somatic hypermutation may play a role. The first large, population-based study of PTL indicated that age, stage, histologic subtype, and treatment modality have prognostic implications. The U.S. Food and Drug Administration approval of rituximab for non-Hodgkin's lymphoma has improved standard chemotherapeutic options, as data on efficacy in nodal and other extranodal lymphomas have been extrapolated to PTL.

SUMMARY

Advances in the understanding of the histologic subtypes of PTL have led to more accurate diagnosis and tailored treatments. The introduction of a new chemotherapeutic agent has expanded the treatment paradigm for PTL. Important prognostic indicators of survival for patients with PTL have been confirmed in the first population-based study. This article emphasizes current diagnostic and treatment approaches and discusses the potential for future developments.