Cardiac sarcoidosis accompanied by a tumor-like blush on coronary angiography

Abstract

A 71-year-old female was diagnosed with cardiac sarcoidosis by a history of complete atrioventricular block requiring pacemaker implantation and a focal thinning of basal interventricular septum (IVS) on echocardiography. Coronary angiography showed a tumor-like blush fed by septal branch of left anterior descending artery and right coronary artery concomitant with a coronary-to-right ventricle shunt. Echocardiography showed a low echoic mass at mid-IVS with an abnormal shunt flow into right ventricle. Fluorodeoxyglucose (FDG)-positron emission tomography (PET) showed an uptake at the corresponding site of mid-IVS. Eight months after the initiation of steroid therapy, FDG-PET showed no abnormal uptake at mid-IVS, suggesting decreased activity of cardiac sarcoidosis. We experienced a case of cardiac sarcoidosis with FDG uptake accompanied by a tumor-like blush at mid-IVS. The present case suggests the involvement of microvascular accumulation in the activity of cardiac sarcoidosis.

<Learning objective: The detailed mechanism of granuloma formation in patients with sarcoidosis has not been clarified. Although the involvement of microvascular accumulation in the activity of extracardiac granuloma including lung and retina has been reported, the involvement in the activity of cardiac sarcoidosis remains to be elucidated. The present case with a tumor-like blush on coronary angiogram suggests the involvement of microvascular accumulation around the granuloma of cardiac sarcoidosis.>

Introduction

Sarcoidosis is characterized by the development of non-caseating epithelioid granulomas in multiple organs. Although the exact pathogenesis of granuloma remains unclear, the involvement of microvascular accumulation in the extracardiac granuloma has been reported [1,2]. However, the involvement of microvascular accumulation in cardiac sarcoidosis remains to be elucidated. Herein, we report a case of cardiac sarcoidosis with a tumor-like blush on coronary angiogram, suggesting the presence of microvascular accumulation surrounding the granuloma of cardiac sarcoidosis.

Case report

A 71-year-old female with a history of complete atrioventricular block requiring pacemaker implantation was diagnosed with sarcoidosis based on the representative histological findings of non-caseating epithelioid granulomas obtained from lung lesion. Echocardiography showed a focal thinning of basal interventricular septum (IVS) and left ventricular systolic dysfunction (left ventricular ejection function: 40%). Blood test showed increased levels of angiotensin-converting enzyme (24.4 IU/L; normal range: 8.3–21.4 IU/L) and brain natriuretic peptide (131.9 pg/mL; normal range <18.4 pg/mL). Fluorodeoxyglucose (FDG)-positron emission tomography (PET) showed a focal FDG uptake in mid-IVS (Fig. 1A). From these findings, the patient was clinically diagnosed with cardiac sarcoidosis according to the Guideline on Diagnosis and Treatment of Cardiac Sarcoidosis provided by the Japan Circulation Society [3].

Fig. 1.

Cardiac sarcoidosis with a tumor-like blush and abnormal shunt at mid-interventricular septum. (A) Fluorodeoxyglucose (FDG)-positron emission tomography (PET) showing a FDG uptake in mid-interventricular septum (arrow). (B) Right coronary angiography showing a tumor-like blush (arrow) fed by right ventricular branch. (C) Left coronary angiography showing a tumor-like blush (arrow) fed by septal branch. (D) Echocardiography in parasternal long-axis view showing a low-echoic thickening of mid-interventricular septum in end diastolic phase (arrow). A focal thinning of basal interventricular septum was observed (arrowhead). (E) Echocardiography in left ventricular short-axis view showing a shunt flow from mid-interventricular septum into right ventricle in diastolic phase. (F) FDG-PET eight months after the corticosteroid therapy showed no abnormal FDG uptake in mid-interventricular septum (arrow). LV, left ventricle; RV, right ventricle.

Coronary angiography was performed to discriminate concomitant coronary artery disease as the cause of left ventricular wall motion abnormality. Right (Fig. 1B, Video 1) and left (Fig. 1C, Video 2) coronary angiography showed a tumor-like blush fed by septal branch of left anterior descending artery and right coronary artery at around mid-IVS. Abnormal shunt from the tumor-like blush to right ventricle was observed on left coronary angiography. On echocardiography, a low-echoic thickened area with a shunt into right ventricle was observed at mid-IVS (Fig. 1D, E) in accordance with the location of the tumor-like blush. We initiated corticosteroid therapy with prednisolone 30 mg/day followed by the de-escalation and the maintenance dose of 7.5 mg/day.

Eight months after the initiation of corticosteroid therapy, FDG-PET showed no abnormal uptake in the mid-IVS (Fig. 1F) although the size of low-echoic area on echocardiography had not changed.

Discussion

We have witnessed a case of cardiac sarcoidosis with FDG uptake accompanied by a tumor-like blush on coronary angiography. The tumor-like blush on coronary angiogram represents the involvement of microvascular accumulation in the formation and the development of cardiac tumor. It has been reported in cases with cardiac angiosarcoma or myxoma [4,5]. However, the involvement of microvascular accumulation in cases of cardiac sarcoidosis has not been elucidated. In the present case, the location of the tumor-like blush matched with the location of FDG uptake and a low-echoic thickened area on echocardiography. Thus, the involvement of microvascular accumulation in the granuloma of cardiac sarcoidosis was suggested in the present case.

Granuloma formation in patients with sarcoidosis has been considered as a result of focal immune response against the uncertain antigen and subsequent enhanced inflammatory reaction. The microvascular involvement as conduit of inflammatory cells and cytokines activated by the increased secretion of tissue necrosis factor alpha and interferon gamma from mast cells and natural killer cells has been also suggested [6,7]. In fact, microvascular accumulation around the granuloma has been reported in extracardiac lesions of sarcoidosis [1,2]. Although the direct relationship between the microvascular accumulation and the granuloma formation was not demonstrated due to the lack of histological investigation in the present case, the correlation between the two was suggested by careful co-registration of the location on coronary angiography, echocardiography, and FDG-PET. The association between the status of microvascular accumulation and disease activity has been further suggested. Several reports have demonstrated that corticosteroid therapy improved disease activity and decreased subretinal neovascularization in patients with sarcoidosis [8,9]. Although we are uncertain, the subsequent changes in tumor-like blush after corticosteroid therapy, it might be diminished according to the decreased disease activity and the disappearance of FDG uptake. In the present case, we further witnessed an abnormal shunt from the corresponding site of tumor-like blush on both coronary angiography and echocardiography. This might be caused by the rupture of surrounding vessels around the granuloma [10]. An unclear issue regarding the present rare findings may be the general frequency among cases with cardiac sarcoidosis. We are still uncertain if we encountered a phenotype with hyper vascular involvement or we incidentally captured the dynamic phase of vascular involvement through the common course of morphological change in granuloma among patients with cardiac sarcoidosis.

Declaration of Competing Interest

None.

Editor: Dr. K. Yamamoto