Serum IgG4-negative IgG4-related disease with a cardiac mass: A case report

Although IgG4-related disease (IgG4-RD) can affect various organs, its association with a cardiac mass is exceptionally rare. Here, we report a case of a woman with IgG4-RD and a cardiac mass and discuss 10 similar cases reported previously. PATIENT CONCERNS: A 65-year-old woman was referred to our hospital for chest discomfort and back pain. DIAGNOSES: In accordance with the 2019 ACR/EULAR diagnostic criteria for IgG4-RD, she was diagnosed with IgG4-RD based on dense lymphocytic infiltration on histopathology, IgG/IgG4-positive cell ratio <40%, >10/hpf IgG4-positive cells on immunostaining, and paraspinal zone soft tissue lesions in the chest. INTERVENTIONS: An external pacemaker was implanted for the complete atrioventricular block on the electrocardiogram. After the diagnosis of IgG4-RD, she was treated with glucocorticoids and rituximab. OUTCOMES: She remains under observation without disease recurrence. LESSONS: IgG4-RD are usually treated with glucocorticoids; however, in cases of a cardiac mass, life-threatening complications may occur and surgery is often needed. Combination therapy with glucocorticoids and rituximab may be effective even in patients with IgG4-RD and cardiac mass, which may avoid the need of invasive treatments, such as surgery.