Primary schwannoma of the right atrium: successful surgical resection.

Nonmyxomatous primary cardiac tumors are rare. Primary neurogenic tumors of the heart originating in the nerve sheath are extremely uncommon, and to date, 10 cases of neurilemomas, or schwannomas, have been reported. We report the case of a patient with a right atrial tumor who underwent a successful resection; histological examination revealed a benign primary schwannoma of the heart. A 56-year-old asymptomatic woman had a spongy mass found in the bladder wall during cystoscopy. Resection was recommended and a preoperative chest roentgenogram showed an abnormal right cardiac silhouette. Computed tomography revealed a heterogeneous solid tumoral mass in the right atrium wall, with calcifications inside, leading to compression of the right atrium and superior vena cava. Angiogram and coronary arteriography were performed. No coronary lesions were found, and a mass was found in the right atrium wall projecting into the chamber (Fig. 1-A). The patient underwent surgery with cardiopulmonary bypass, but without cardiac arrest; a venous cannula was placed in the superior vena cava. The mass was found in the right atrial wall close to the cavo-atrial junction and was completely removed. (Fig. 1-B) The right atrial wall was reconstructed with a bovine pericardial patch. The mass consisted of an encapsulated ovoid tumor, measuring 6.0 x 4.8 cm and weighing 67 g, with brown and reddish heterogeneous tissue, with white and yellow strips on the cut section; it had a fibroelastic consistency and small calcified areas (Fig. 2). Microscopic sections revealed a mixed proliferation of Antoni type A tissue, with hypercellularity and palisading nuclei and fibers, and Antoni type B tissue with hypocellularity, forming the Verokay corpuscles. (Fig. 2) The diagnosis of benign schwannoma was established. The patient had pleural effusion and acute atrial fibrillation that were promptly and successfully treated in the early postoperative period. As she resumed sinusal rhythm, no anticoagulation therapy was applied. After discharge, she had an uneventful late outcome and remains asymptomatic 36 months after surgery; echocardiograms have shown no recurrence of the disease. Primary cardiac tumors are rare, found in 0.0017% to 0.28% of autopsies, with 76% being benign, and of these, 40% being myxomas. Schwannomas (neurilemomas) are neurogenic neoplasms arising from a nerve sheath, which often involve cranial nerves, posterior spinal nerve roots, nerve of the extremities, the posterior mediastinum, and the vagus nerve. Figure 1 A. Angiography showing right atrial mass. B. Surgical appearance of the tumor.