Primary benign myopericytoma of the left atrium

Abstract

A 46-year-old woman presented with progressive dyspnea. Physical examination revealed a blood pressure of 140/60 mmHg, a heart rate of 80 bpm and respiration of 16 breaths/min. Heart sounds were regular and distant. No murmurs or rubs were noted. Jugular venous pressure was normal. Lungs were clear, abdomen soft and no peripheral edema was found. The electrocardiogram and the chest X-ray film were normal. Two-dimensional transthoracic echocardiography revealed a large left atrial (LA) mass (31 9 40 9 45 mm), above the mitral valve, and seemingly attached to the posterior wall of the left atrium with a wide pedicle (Fig. 1a, b; Video 1 and 2). Moderate mitral stenosis due to the diastolic obstruction by the tumor and mild mitral regurgitation was observed (Video 3). Mean transmitral gradient was 12 mmHg and mitral valve area was 1.4 cm 2 . Transesophageal echocardiography did not add any additional information. A diagnosis of atrial myxoma was made. The patient underwent surgical removal of the mass. At the time of surgery, the tumor had a smooth surface and a rubbery consistency (Fig. 1c). It was found attached in the LA floor without involvement of either the pulmonary veins or the mitral valve. The tumor was shaved off the atrium. The surgeon decided not to resect the tumor en bloc due to the risk of bleeding in the reconstruction of the floor of the LA. Serial sectioning showed areas of focal necrosis. Histopathologic and immunophenotypic features revealed a primary cardiac benign myopericytoma (Fig. 1d). The patient underwent FDG PET/CT imaging of the chest, abdomen and pelvis, and extracardiac metastases were ruled out. The patient did well and was ultimately discharged home. A follow-up echocardiogram at 24 months disclosed no abnormalities.

Myopericytoma of the Parotid and Molecular Profiling: Report of a Rare Case and Review of the Literature

“…3 More recently, myopericytomas have been found in rare sites, including intracranially, 4 within the gynecologic tract, 5 and within the heart. 6 Myopericytomas are typically benign tumors treated with wide surgical excision. Infrequently, these tumors may recur and rarely malignant myopericytomas have been reported in the literature.…”