Myocardial Fibroma in Gorlin Syndrome by Cardiac Magnetic Resonance Imaging
A 33-year-old woman was referred for cardiovascular magnetic resonance imaging to further assess a left ventricular mass found after an echocardiography. Her past medical history was remarkable for multiple basal cell carcinomas and surgical resection of odontogenic cysts, and her family history was negative for cardiac tumors. The patient was in her usual state of health until 6 months before presentation, when she noted increasing fatigue, atypical chest pain, and exertional dyspnea. She also complained of intermittent palpitations without syncope. A transthoracic echocardiography demonstrated a 6×3-cm mass in the left ventricular lateral wall, with deformation of the left ventricular cavity. Left ventricular systolic global function was normal, and there was a trace amount of mitral regurgitation.
The patient underwent cardiovascular magnetic resonance examination with a 1.5 T scanner (Signa CV/i, General Electric, Milwaukee, Wis) with an 8-channel cardiac phased-array coil. Bright blood cine images by steady-state free-precession techniques revealed a 5.5×3.8×4.2-cm mass that was hypointense compared with normal myocardium arising within the lateral wall of the left ventricle (Figure 1). T1-weighted, double-inversion recovery fast-spin echo (black-blood technique) images showed the discrete mass was isointense to slightly hypointense relative to the surrounding normal myocardium (Figure 2). First-pass perfusion images by fast gradient recalled-echo echo-planar technique immediately after a bolus injection of 0.075 mmol/kg gadolinium-diethylenetriamine pentaacetic acid (Magnevist, Berlex Pharmaceuticals, Wayne, NJ) demonstrated a lack of first-pass enhancement (Figure 3), suggesting low tumor vascularity. Delayed enhancement images (Figure 4) were obtained using an inversion-recovery segmented gradient echo sequence (to null normal myocardium) 10 minutes after gadolinium administration (cumulative dose, 0.15 mmol/kg). There was intense late gadolinium enhancement reflecting an increased extracellular volume of distribution in the left ventricular myocardium. Collectively, the tumor appearance and tissue characteristics were consistent with a fibroma. A diagnosis of cardiac fibroma in association with Gorlin syndrome was made.
The patient subsequently underwent surgical resection of the myocardial mass, which was confirmed to be a cardiac fibroma on pathological examination (Figures 5 to 7⇓⇓). Post-operatively, she developed significant mitral regurgitation necessitating mechanical prosthetic (St Jude Medical, St Paul, Minn) mitral valve replacement without further complications.
Gorlin syndrome is a rare autosomal dominant disorder with complete penetrance and variable expressivity.1 Its estimated prevalence is 1in 57 000. It is caused by mutations in the Patched gene, which acts as a cell-cycle regulator. The hallmark of this syndrome is the presence of multiple basal cell carcinomas, which may appear early in infancy. Other associated features may include craniofacial, central nervous system, musculoskeletal, and genitourinary anomalies. Approximately 3% of cases are associated with cardiac fibromas, which may present later during adulthood rather than the typical infancy or childhood period.1