Evaluation of the diagnostic value of immunoglobulin clonal gene rearrangements in patients with parotid gland MALT lymphoma using BIOMED-2 protocol

Molecular B-cell clonality assay in minor salivary glands as a useful tool for the lymphoma risk assessment in Sjögren's syndrome

OBJECTIVES

Non-Hodgkin's lymphoma (NHL) risk assessment is crucial in Sjögren's syndrome (SS). We studied the prevalence of clonal immunoglobulin gene rearrangements in minor salivary glands (MSG) and their correlations with lymphoma occurrence and with previously established NHL predictors.

METHODS

Molecular B-cell expansion was studied in fresh-frozen MSG of 207 patients with either suspected SS or with suspected lymphoma during SS, using a standardised multiplex PCR assay combined with heteroduplex analysis by microcapillary electrophoresis. The assignation of clonal cases was based on EuroClonality consortium guidelines.

RESULTS

Among 207 studied patients, 31 (15%) had MSG monoclonal B-cell infiltration. Monoclonality was significantly more frequent in patients with SS (28/123, 22.8%) compared with patients without SS (3/84, 3.6%, P<0.001). Monoclonal B-cell infiltration in MSG of SS patients correlated significantly with ongoing salivary gland NHL, salivary gland swelling, CD4+ T-cell lymphopenia, rheumatoid factor (RF) activity, low complement levels and type 2 mixed cryoglobulinemia. The accumulation of biological risk factors was associated with a higher rate of MSG B-cell monoclonality given that patients with only positive RF had no probability of MSG B-cell monoclonality, RF-positive patients with 1 or 2 other risk factors had a 25.0% and 85.7% probability of MSG B-cell monoclonality, respectively.

CONCLUSION

The detection of MSG monoclonal B-cell expansion by this easy-to-perform molecular assay is useful, both at the time of diagnosis and during the course of SS. Monoclonal B-cell expansion is associated with a subset of SS patients presenting either ongoing lymphoma or other established lymphoma predictive factors.

Molecular pathology assists the diagnosis of lymphoepithelial sialadenitis, Sjögren's syndrome and extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue

Background/purpose

Lymphoepithelial sialadenitis (LESA), Sjögren's syndrome (SS), and salivary MALT lymphoma are diseases characterized by lymphoepithelial lesions, and the differential diagnosis between them in the salivary glands is challenging. This study aimed to explore clinicopathological and genetic characteristics of the three diseases.

Materials and methods

We retrospectively analyzed the clinical features, the histomorphology, immunohistochemistry, and genetic profiling by polymerase chain reaction (PCR) and next-generation sequencing (NGS).

Results

There included 68 LESAs, 25 SSs, and 62 MALT lymphomas. Ten cases relapsed in total, and 3 of MALT lymphomas died due to high-level transformation. Immunohistochemical double staining showed FCRL4 cells co-expressed Pax-5 and Ki-67, suggesting FCRL4 cells were proliferative B-cells. The expression level of the FCRL4 was significantly higher in MALT lymphoma than LESA and SS. The detection rates of clonal IGH, IGK, and IGL gene rearrangements in MALT lymphoma with a sensitivity of 83.33%. Monoclonal immunoglobulin gene rearrangements were confirmed in five suspected patients by NGS (100%).

Conclusion

FCRL4 B cells might play an important role in the formation of lymphoepithelial lesions and might be as a diagnostic positive marker of salivary MALT lymphoma. The application of multiple detection methods could significantly improve the diagnostic accuracy for MALT lymphomas from LESA and SS.

MALT lymphoma of the head and neck: Surgery alone can be an option

OBJECTIVES

To retrospectively analyze the general characteristics of MALT lymphoma in the head and neck and provide clinicians with new ideas for diagnosis and treatment.

MATERIALS AND METHODS

114 (94.2%) of 121 complete follow-up data were obtained. A single-center retrospective study was conducted on 114 patients with MALT diagnosed from 2010 to 2020.

RESULTS

42 (36.8%) of 114 patients had Sjogren's syndrome before, and there is a significant difference in gender between SS-MALT and non-SS-MALT. As for the treatment method, there is no significant difference in the overall survival between surgery with or without chemoradiotherapy.

CONCLUSION

MALT lymphoma of the head and neck is clinically characterized by a favorable prognosis, always associated with SS. Surgery with or without chemoradiotherapy has little difference in the prolongation of survival time.

Indicators for Malignant Transformation in Patients With Lymphoepithelial Lesion

PURPOSE

Salivary lesion (LEL) represents a unique disease, and some patients have malignant transformations. The study aims were to estimate the frequency of malignant transformation and the subtype of the malignant component and to identify factors associated with malignant transformation and subtype of the malignant component in patients with LEL.

PATIENTS AND METHODS

This study was based on a retrospective cohort study between 2005 and 2017 from patients who were diagnosed as LEL. The predictor variable was composed of a set of variables grouped into demographic, clinical, and pathologic features. The outcome variables were malignant transformation status and subtype of the malignant components. All parameters between the predictor variables and outcome variables were analyzed using the χ² test and a logistic regression model.

RESULTS

The sample was composed of 252 cases of LEL (including with or without malignant transformation) with a mean age of 50.3 years; 58 (58 of 252; 23.0%) were males, 194 (194 of 252; 77.0%) were females. The parotid gland was the most common site of LEL (206 of 252; 81.7%), and 36.5% (92 of 252) of the patients had a history of Sjögren syndrome (SS). Masses greater than 2 cm in diameter had evidence of malignant transformation (P < .001). Factors associated with the subtype of malignant components were a history of SS (P < .001) and Epstein-Barr virus infection. The percentages of nonmalignant transformations, LEL with extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT lymphoma), and LEL progressing to lymphoepithelial carcinoma were 44.8 (113 of 252), 47.6 (120 of 252), and 7.6% (19 of 252), respectively.

CONCLUSIONS

More than half of cases have a malignant transformation, and MALT lymphoma is the most common malignant subtype. A larger mass (>2 cm) is an independent indicator of malignant transformation in LEL patients. History of SS among LEL patients is considered a risk factor for MALT lymphoma.

Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue in the oromaxillofacial head and neck region: A retrospective analysis of 105 patients

Background

Extranodal marginal zone B‐cell lymphoma of mucosa‐associated lymphoid tissue (MALT lymphoma) in the oromaxillofacial head and neck region is rare, with limited data available. This retrospective study explored the clinical features, stage, treatment, and prognosis of this disease.

Methods

Overall, 105 patients with MALT lymphomas in the oromaxillofacial head and neck region were included in this retrospective analysis. SPSS 22.0 software package was used for data analysis and a two‐tailed P value of ≤.05 was considered statistically significant. Primary endpoints of the study were the complete response (CR) rate, overall survival (OS), and progression‐free survival (PFS).

Results

About 52% of the patients had long‐term xerostomia, autoimmune diseases, or chronic parotitis and 81% had diseases involving the large salivary glands. Ann Arbor staging of the patients was as follows: stages I/II, 73 patients and stages III/IV, 32 patients. In the 97 patients followed up, CR rate after initial treatment was 80%. Tumor progression was observed in 12 patients and 14 patients died. There was a significant difference between the rate of CR in localized (87%) and disseminated (67%) lymphoma patients (P = .02). The 5‐ and 10‐year PFS of the localized lymphoma patients were both 91%, whereas those of the disseminated lymphoma patients were 83% and 65%, respectively (P = .03). The 5‐year PFS rates of the chemotherapy and non‐chemotherapy groups in the disseminated lymphoma patients were 85% and 73% (P = .04). Meanwhile, the 5‐year PFS rates of the rituximab and non‐rituximab groups in the disseminated lymphoma patients were 100% and 70% (P = .03). In multivariate analysis, MALT Lymphoma International Prognostic Index (MALT‐IPI) was an independent prognostic factor affecting OS, whereas Ann Arbor staging affected PFS.

Conclusions

This study suggests that the outcome after initial treatment of MALT lymphomas in the oromaxillofacial head and neck region is satisfactory and that this disease progresses slowly. The CR rate and PFS of localized lymphoma patients are better than those of disseminated lymphoma patients. Systemic treatment (chemotherapy or rituximab) may improve PFS in disseminated disease patients. MALT‐IPI and Ann Arbor staging are independent prognostic factors.

18F-FDG PET/CT for staging and response assessment of primary parotid MALT lymphoma with multiple sites involvement: A case report

RATIONALE

Mucosa-associated lymphoid tissue (MALT) lymphoma is an extranodal low-grade B cell lymphoma that generally exhibits an indolent clinical course. Currently, the application of F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) in MALT lymphoma is still controversial. Herein, we reported a case of using F-FDG PET/CT for staging and response assessment of primary parotid MALT lymphoma with multiple sites involvement. As far as we know, there are no similar case reports have been published before.

PATIENT CONCERNS

A 71-year-old woman, who received mass resection twice during the past 2 years due to the repeatedly relapse of facial painless masses and diagnosed as reactive lymphoid hyperplasia by pathologic tests. However, the pathological diagnosis was then changed to primary parotid MALT lymphoma after left parotidectomy operation because of a new mass found in her left parotid. Four months later, the right eyelid of the patient swelled with a blurred vision. Then, F-FDG PET/CT scan was performed for staging, and the imaging results showed an abnormal increase of F-FDG uptake in multiple sites including bilateral ocular adnexal, lungs, pleura, occipital subcutaneous tissue, left kidney, and lymph nodes.

DIAGNOSES

The patient was diagnosed as primary parotid MALT lymphoma with Ann Arbor stage of IVA based on the F-FDG PET/CT findings.

INTERVENTIONS

The patient received 4 cycles of chemotherapy, followed by a partial metabolic remission (PMR), which was determined by interim F-FDG PET/CT, and finally additional 2 cycles of chemotherapy.

OUTCOMES

The follow-up study illustrated that the patient had been alive and doing well at 12 months after chemotherapy.

LESSONS

Although MALT lymphoma normally localizes in the primary organs, the involvement of multiple organs and lymph nodes is possible. The use of PET/CT demonstrated significant clinical values in the accurate staging and response assessment of F-FDG-avid MALT lymphoma. It is potentially useful for indicating the progress and transformation of MALT lymphoma, and guidance in localization of pathological biopsy. It is also helpful for clinicians to choose reasonable treatment strategy and improve the prognosis of patients.