Cardiac Fibroma Presenting With Left Bundle Branch Block in an Adult With Gorlin Syndrome.

A 60-year-old man presented with chest pain and palpitations. His troponin level was normal, and electrocardiography showed left bundle branch block (LBBB) (Fig. 1). Echocardiogram demonstrated moderate left ventricular systolic dysfunction, and no mass was clearly reported (Fig. 2). His invasive coronary angiogram was normal. Cardiac magnetic resonance imaging showed a solitary, ovoid (5 × 2.7 cm), well-circumscribed intramural mass in the mid- to apical lateral segments. The lesion showed low intensity relative to the myocardium on T1w images (Fig. 3A) and T2w images (Fig. 3B). On late gadolinium-enhanced images, the mass demonstrated intense homogenous enhancement (Fig. 3C). Imaging characteristics of the mass were in keeping with cardiac fibroma. In retrospect, an unclear, round mass was suspected in some of the echocardiogram images; this is a rare manifestation that can be missed even by an experienced operator.On review of the patients' previous imaging records, x-ray and computed tomography of the mandible demonstrated multiple lytic lesions consistent with keratocystic odontogenic tumors (Fig. 4). Biopsy results of multiple skin lesions confirmed basal cell nevi. A conclusive diagnosis of cardiac fibroma associated with Gorlin syndrome was established and supported by further genetic testing.Gorlin syndrome is a rare autosomal dominant disorder with complete penetrance and variable expressivity,1 with estimated prevalence of 1 in 19,000.2 The syndrome is associated with multiple basal cell carcinoma, and additional features may include craniofacial, central nervous system, musculoskeletal, and genitourinary anomalies. Approximately 3% to 5% of cases are associated with cardiac fibromas. Cardiac fibroma is a common pediatric cardiac tumor with only approximately 15% of cases occurring in adults.1 Arrhythmia is a common presentation, but in the index case, conduction abnormality (LBBB) was noted.Magnetic resonance imaging shows unique T1 and T2 characteristics, including intense homogenous late gadolinium enhancement.3 Left bundle branch block usually is a sign of underlying heart disease. This case is cardiac fibroma presenting with LBBB. Cardiac magnetic resonance imaging can be an important diagnostic step in patients with newly found LBBB.