Complete Heart Block Caused by Diffuse Pseudotumoral Cardiac Involvement in Granulomatosis With Polyangiitis
A 56-year-old woman presented to the emergency room with increasing dyspnea for 1 month and syncope. She had only a history of unexplained bilateral deafness; she had no history of cardiovascular disease and no cardiovascular risk factors. ECG demonstrated a complete (third-degree) suprahisian atrioventricular block with a heart rate of 48 bpm (Figure 1). Transthoracic echocardiography showed preserved systolic left and right ventricular function and the presence of an infiltrative mass in the interatrial septum (Figure 2A and Movie I in the online-only Data Supplement), invading both the right and left atria. Laboratory tests were unremarkable. This was confirmed by transesophageal echocardiography (Figure 2B and 2C and Movies II and III in the online-only Data Supplement). 18F-fluorodeoxyglucose positron emission tomography/computed tomography demonstrated a highly hypermetabolic area in the interatrial septum (maximum standardized uptake value, 16.4) suggestive of malignancy (Figure 2D). Cardiac magnetic resonance imaging was performed to characterize the mass. It was isointense and homogeneous on fast-spin-echo T1-weighted images (Figure 3A) and mildly hyperintense on T2-weighted imaging (Figure 3B) and steady-state free-precession cine imaging (Figure 3C and Movie IV in the online-only Data Supplement). The mass infiltrated both parts of the interatrial septum with extension to the posterior part of the aortic root above and to the inferior right atrial wall below. On gadolinium-enhanced first-pass perfusion imaging, it demonstrated high and homogeneous contrast uptake between the ventricular (Figure 3D) and myocardial (Figure 3E) phases. On late gadolinium enhancement imaging, it presented marked homogeneous hyperenhancement (Figure 3F). Late gadolinium enhancement images also demonstrated diffuse pericardial enhancement and a transmural and systematized myocardial enhancement in the apex, suggestive of myocardial infarction, despite normal coronary angiography and the absence of chest pain. On the basis of these features, primary cardiac lymphoma was suspected. A surgical biopsy followed by complete resection of the mass was performed with a bovine pericardial patch to close the interatrial septum defect. Postoperative echocardiography showed the absence of residual tumor and complete closure of the interatrial septum (Figure 4A and Movies V and VI in the online-only Data Supplement). Unfortunately, the heart block did not resolve after surgery, and the patient required a permanent pacemaker (Figure 4B). Histopathology demonstrated extensive necrosing granuloma (Figure 5), compatible with a granulomatosis with polyangiitis (GPA). However, all the immunology markers (anti-neutrophil cytoplasmic antibodies) remained negative, with doubt about the definitive diagnosis. Six months later, the patient presented a severe sinusitis. A cavum biopsy confirmed the diagnosis of GPA, and treatment with corticosteroids and cyclophosphamide was initiated.
We present a case of limited GPA in which diffuse cardiac involvement (endocarditis, pericarditis, and myocardial infarction) was an early presentation of the disease and was associated with atrioventricular block caused by infiltration of the interatrial septum. GPA is a small-vessel vasculitis associated with necrosis and granulomatosis. Cardiac involvement occurs in 6% to 44% of patients.1 Pericarditis2 and coronary vasculitis are the most frequent findings (50% of cases), but myocarditis, endocarditis, conduction system granulomata, and pulmonary artery involvement are also described. The clinical diagnosis may be difficult because symptoms such as sinusitis and renal failure are nonspecific and inconstant. Cytoplasmic anti-neutrophil cytoplasmic antibodies are present in the majority of cases with high specificity (80%–90%), especially in generalized form, but may remain negative up to 40% in limited disease,3 so sensitivity may be low. In this case, the differential diagnosis of interatrial septal tumors included myxoma, lymphoma, sarcoma, bronchogenic cyst, and benign hemangioma. Myxoma was ruled out because of the invasive character of the mass and the intense metabolic activity on fluorodeoxyglucose positron emission tomography. Lymphoma was suspected because of the infiltrative aspect, the mild signal hyperintensity on T2, the homogeneous aspect of contrast captation, and the high fluorodeoxyglucose uptake. However, contrast uptake on late gadolinium enhancement is frequently not so marked. Primary cardiac sarcoma was another differential diagnosis but presents frequently with heterogeneous gadolinium uptake and an area of necrosis. Pericardial enhancement can be found in both lymphoma and angiosarcoma, but these tumors most commonly affect the right atrial free wall.
Although rare, GPA should be considered in the diagnosis of cardiac mass, especially in the interatrial septum. Cardiac magnetic resonance imaging provided substantial information about the disease extension and diagnosis.
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/lookup/suppl/doi:10.1161/CIRCULATIONAHA.115.017843/-/DC1.
- © 2015 American Heart Association, Inc.
- Grant SCD,
- Levy RD,
- Venning MC
- Florian A,
- Slavich M,
- Blockmans D,
- Dymarkowski S,
- Bogaert J