Cardiac Tuberculosis on 18F-FDG PET Imaging—A Great Masquerader of Cardiac Sarcoidosis

Abstract

A young gentleman with suspected cardiac sarcoidosis and LV dysfunction whose CMR revealed multifocal subepicardial to mid myocardial linear enhancement in the left ventricular myocardium underwent cardiac 18F-FDG PET imaging. The images revealed patchy regions of increased FDG uptake involving the apical to mid anterolateral, mid to basal anteroseptal/ right ventricular and mildly increased FDG uptake in apical inferior segments of the LV myocardium concordant with CMR findings. Whole body PET CT imaging showed multiple hypermetabolic supra and infra diaphragmatic lymphadenopathy, with no pulmonary lesion identified. Biopsy from the left para aortic lymph node revealed necrotizing granulomatous inflammation consistent with tuberculosis. Based on the histopathological findings of the lymph nodes, diagnosis of cardiac tuberculosis was made, given the similar imaging appearances in both sarcoidosis and TB. This case highlights that cardiac TB although rare, should be included in the differential diagnosis in patients with suspected infiltrative cardiomyopathy, particularly in TB endemic regions.

Tuberculosis of the Heart: A Diagnostic Challenge

“…Recently, cardiac TB was diagnosed using 18F-FDG PET. In one of their case reports, Sundaraiya et al presented a case of cardiac tuberculosis that resembled sarcoidosis [ 61 ]. PET imaging revealed patchy regions of increased FDG uptake in the apical to mid anterolateral, mid to basal anteroseptal/right ventricular, and moderately increased FDG uptake in the apical inferior LV myocardium CMR findings ( Figure 7 , This image was adapted from Sundaraiya et al [ 61 ]).…”

“…In one of their case reports, Sundaraiya et al presented a case of cardiac tuberculosis that resembled sarcoidosis [ 61 ]. PET imaging revealed patchy regions of increased FDG uptake in the apical to mid anterolateral, mid to basal anteroseptal/right ventricular, and moderately increased FDG uptake in the apical inferior LV myocardium CMR findings ( Figure 7 , This image was adapted from Sundaraiya et al [ 61 ]). On whole-body PET CT imaging, several hypermetabolic supra and infra diaphragmatic lymphadenopathy was detected, but no pulmonary lesion was detected.…”

“…On whole-body PET CT imaging, several hypermetabolic supra and infra diaphragmatic lymphadenopathy was detected, but no pulmonary lesion was detected. Inflammation of the necrotizing granulomatous type in the left para-aortic lymph node was consistent with tuberculosis [ 61 ]. Even though tuberculosis closely resembles sarcoidosis, FDG-PET is helpful.…”

“…The ability of FDG-PET to define inflammation and different stages of myocardial damage enables the early detection of cardiac infiltrative diseases such as sarcoidosis and TB and theoretically improves the test’s sensitivity at the price of specificity [ 61 , 79 ]. As a diagnostic tool, the increased sensitivity of FDG-PET is crucial for detecting illness at an earlier stage.…”

“…As a diagnostic tool, the increased sensitivity of FDG-PET is crucial for detecting illness at an earlier stage. Inflammatory processes involving FDG absorption are mild to moderate in the pericardium, and its use in detecting myopericardial TB is limited [ 61 ].…”