LV Mass in a Patient With History of Neuroblastoma
A 22-year-old man with a medical history of stage IV neuroblastoma, diagnosed at the age of 3, is noted to have a cardiac mass. Prior cancer-directed therapy included surgical resection, chemotherapy with 150 mg/m2 cumulative dose of doxorubicin, etoposide, high-dose alkylating agents, cisplatin, and carboplatin; total body irradiation; and autologous bone marrow transplant. Post-therapy, he did not relapse but developed late effects from cancer-directed therapy. He has growth hormone deficiency, primary hypothyroidism, primary hypogonadism, and osteochondroma of the wrist.
At long-term follow-up, a screening transthoracic echocardiogram (TTE) noted a single, echodense, well-circumscribed, globular, 1.3 x 1.0 cm mass in the anterolateral aspect of the mid to apical portion of the left ventricle (LV) (Figure 1). On three-dimensional (3D) TTE, the mass appeared pedunculated and predominantly homogenous with some echolucent areas (Figure 2). There was normal biventricular and valvular function and no pericardial effusion. Cardiac magnetic resonance imaging (MRI) demonstrated a T2 hyperintense mass located near the anteroseptal wall of the LV and attached to the anterior wall by thin septae (Figure 3A). The mass was slightly mobile with each cardiac cycle without evidence of outflow or inflow obstruction. There was no clear enhancement on the first pass perfusion imaging and the 1-minute delayed imaging; however, delayed gadolinium enhancement was present on the 10-minute post-contrast delayed imaging (Figure 3B-C).
Taking into consideration the clinical presentation and cardiac imaging findings, what is the likely etiology of the mass?