Lymphoma in Sjögren's syndrome: no need for repetitive screening ultrasounds of the major salivary glands and neck in asymptomatic patients.

Objective: Patients with primary Sjögren's syndrome (pSS) have an increased risk of lymphoma, especially mucosa-associated lymphoid tissue (MALT) lymphoma of the salivary glands. Risk factors for lymphoma are well known, but there are no studies on screening by imaging. Therefore, we aimed to assess the usefulness and adverse effects of ultrasound of the major salivary glands and neck as lymphoma screening.

Method: A retrospective, single-centre, analysis of imaging studies in pSS patients was conducted. Imaging studies were classified as either screening examinations (asymptomatic patients) or occasion-related (imaging due to signs of lymphoma or at least moderate systemic activity). Results were categorized as: not suspicious; requiring control; triggering tissue sampling with exclusion of lymphoma; or triggering tissue sampling with diagnosis of lymphoma.

Results: The study included 134 patients and covered 1031 patient-years. Lymphoma was diagnosed in 15 patients (11.2%), all of whom had clinical signs of lymphoma at the time of diagnosis. During this period, 569 screening examinations and 179 occasion-related examinations were conducted. None of the screening examinations detected lymphoma, but follow-up imaging was recommended in 17.1% (95% CI 14.2-20.4%) and invasive exclusion of lymphoma was performed in 0.5% (95% CI 0.1-1.5%). In contrast, lymphoma was detected in 6.1% (95% CI 3.5-10.6%) of occasion-related examinations.

Conclusion: pSS patients with neither signs of lymphoma nor increased systemic disease activity did not benefit from screening. In contrast, patients with symptoms of lymphoma or at least moderate systemic activity can benefit from imaging of the neck and major salivary glands.