Primary cardiac schwannoma: comprehensive imaging and surgical management

Extract

A 46-year-old woman was found to have a cardiac tumour during a physical examination 2 months ago. Echocardiography revealed a 40 × 41 × 34 mm hypoechoic mass located between the pulmonary artery and the upper segment of the interventricular septum, with a visible capsule and heterogeneous internal echoes (Panel A). Computed tomography coronary angiography showed a mass within the interventricular septum, near the right ventricular outflow tract, with homogeneous density and mild enhancement. The left main coronary artery and the left anterior descending artery were closely adjacent to the tumour surface (Panels B–D). To better characterize the mass, contrast enhanced cardiac magnetic resonance imaging was performed, showing a 42 × 32 × 38 mm mass with clear boundaries and a visible capsule (Panel E). The mass was isointense on T1 weighted imaging and hyperintense on T2 weighted imaging and T2-weighted short-tau inversion recovery, with homogeneous signal intensity (Panels F–H). However, native T1, T2, and ECV (extracellular volume) fraction mapping revealed heterogeneous signal intensity within the tumour (Panels I–K), consistent with the heterogeneous enhancement observed on late gadolinium enhancement imaging (Panel L). The areas of patchy enhancement within the lesion had higher T1, T2, and ECV values compared with the cystic areas with low enhancement (T1: 1750–1942 ms; T2: 97–137 ms; ECV: 50%–70%). 2D flow imaging showed no obvious signs of local obstruction (Panel M). The tumour was completely resected surgically. Histological and immunohistochemical examinations confirmed the diagnosis of cardiac schwannoma (Panel N). In conclusion, the cardiac tumour, located near the great vessels with a capsule and heterogeneous enhancement, including cystic areas of low enhancement, suggests a schwannoma. Cardiac magnetic resonance parametric mapping is more sensitive in differentiating tissue pathological components. This case represents an extremely rare primary cardiac tumour, with surgical resection being the primary and effective treatment. Four months post-surgery, the patient has shown no recurrence and remains asymptomatic.