https://orcid.org/0000-0003-3143-8796
A 60-year-old woman was presented to our hospital with 38°C fever, limb arthralgia, and progressive bilateral leg oedema for 2 months. Her blood test showed that white blood cell count was 29 380/μL and C-reactive protein was 17.46 mg/dL, while anti-nuclear antibody, rheumatoid factor, and anti-cyclic citrullinated peptide antibody were negative. Active synovitis of the knees and wrists was revealed by musculoskeletal ultrasonography. Prednisolone and methotrexate were initiated for suspected rheumatoid arthritis; however, her symptoms and laboratory data did not improve. Positron emission tomography–computed tomography was then performed and found focal, prominent accumulation in the left ventricle (arrow in Panel A). Echocardiography showed a 1.6 cm × 2.2 cm mass at the anterior wall of the apical myocardium (Supplementary data online, Video, arrow in Panel B). After surgical excision of the tumour, her symptoms dramatically improved without medication. Therefore, we diagnosed her illness as paraneoplastic rheumatic syndrome caused by primary cardiac tumour. The pathological diagnosis was undifferentiated intimal sarcoma by positive immunostaining with cyclin-dependent kinase 4 and MDM2 which inhibits tumour suppressor p53 (upper row in Panel C). Interestingly, most of the sarcoma cells were strongly immunostained with vascular endothelial growth factor (VEGF), whereas fewer cells were stained with interleukin-6 (lower row in Panel C), suggesting that VEGF secreted from the sarcoma caused paraneoplastic syndrome. Serum concentration of VEGF becomes an index of sarcoma activity and is associated with rheumatic symptoms. However, it is rare that cardiac sarcoma presents paraneoplastic rheumatic syndrome without any cardiac symptoms as in this case.
Supplementary data are available at European Heart Journal - Cardiovascular Imaging online.
