Cutaneous mucosa-associated lymphoid tissue lymphoma complicating Sjögren's syndrome: A case report and review of literature

The risk of developing non-Hodgkin lymphoma and the mortality rate in primary Sjögren's syndrome: a single-centre, retrospective cohort study

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease that is manifested by the sensation of dry eyes and dry mouth. The higher incidence of non-Hodgkin lymphoma (NHL) among pSS has already been extensively researched. However, there are uncertanties whether the mortality risk in pSS patients and in pSS patients with NHL is increased. The purpose of this study was to describe the prevalence of NHL among pSS patients and to calculate their mortality risk. We retrospectively analysed data on 1367 patients treated in our rheumatology department under the ICD-10 code M35.0. The study finally recruited 155 patients who met the 2016 ACR/EULAR criteria for the diagnosis of pSS. Descriptive statistics was used in data analysis. We applied the indirect standardization by age to compare the incidence rate of NHL in our cohort to general population. Additionally, we compared the mortality in our study to the general population by calculating the standardized mortality ratio (SMR). The overall incidence rate of NHL was 440 per 100,000 patient-years. The SIR compared to the general population was 30.13 (95% CI 12.87-54.63). The overall mortality rate of pSS patients in our cohort was nearly identical to that of the general population (SMR = 0.98 [95% CI (0.47-1.69)]). This study confirms that there are significant differences in lymphoma prevalence, histology, and prognosis across the studied populations. Furthermore, this study found that patients with pSS have similar mortality risk as the general population, and no patient in our cohort died from NHL.

Thymus and lung mucosa-associated lymphoid tissue lymphoma with adenocarcinoma of the lung: a case report and literature review

BACKGROUND

Mucosa-associated lymphoid tissue (MALT) lymphoma is a common, low-grade, malignant B-cell lymphoma. However, simultaneous MALT lymphoma in the thymus and lung is extremely rare, and concomitant adenocarcinoma of the lung is even rarer. Herein, we report a rare case of a collision tumor in which MALT lymphoma was found in both the thymus and lung with Sjögren's syndrome (SS) and adenocarcinoma in the lung.

CASE PRESENTATION

A physical examination of a 32-year-old woman revealed an anterior superior mediastinal space-occupying lesion, and chest computed tomography (CT) indicated a nodular ground-glass opacity and irregular mixed-density focus in the right lung. All lung cancer-related tumor biomarkers were within normal ranges. The thymus and part of the lung tissue were surgically resected. The histopathology and molecular examinations confirmed MALT lymphoma of the thymus and lung with lung adenocarcinoma. SS was also diagnosed. No special postoperative treatment was performed for the MALT lymphoma, and the patient underwent immunosuppressive therapy for SS after 4 months of follow-up observation.

CONCLUSIONS

MALT lymphoma of the thymus and lung tissues has no specific presentation on imaging and is difficult to differentiate from common malignant tumors, and the definite diagnoses of these tumors are highly dependent on histopathological examination in combination with molecular testing and cytogenetics. SS may be an important potential condition for the occurrence of MALT lymphoma in the thymus and lung. Additional similar cases are needed to clarify the biological pathways and potential molecular mechanisms of rare lymphomas and collision tumors.