Primary Left Atrial Leiomyosarcoma: Literature Review and Lessons of a Case

Abstract

Primary cardiac sarcoma is an uncommon disease. In particular, leiomyosarcoma of cardiovascular origin is extremely rare. Half of all cardiac leiomyosarcomas are located in the left atrium. Due to the extreme rarity of left atrial leiomyosarcoma, there is no great experience in its management. This review includes a report of a case of left atrial leiomyosarcoma followed up over 45 months. The literature review examines the distribution of left atrial leiomyosarcoma, the physiological reasons for the tendency of cardiac leiomyosarcoma to be localized to the left atrial cavity, the clinical and physical appearance of this disease, and the key differences between left atrial leiomyosarcoma and the most common left atrial tumor, myxoma. The morphological features, using light and electron microscopy and immunochemical staining, are discussed. Treatment modalities including adjuvant therapy and surgical resection are examined and their effectiveness compared. Opinions regarding the results and optimal treatment of leiomyosarcoma are not always in agreement. This highlights the need for inter-hospital comparison to determine the optimal treatment regimen.

State of the art paper Sarcomas of the heart as a difficult interdisciplinary problem

“…Large veins are composed of a greater amount of smooth muscles. In the arterial system high pressure results in the dedifferentiation to cells producing fibrous elements such as collagen and elastin [36]. The above states permit the initiation of the neoplastic process.…”

“…So far, only 400 cases of great vessel leiomyosarcomas have been reported. They concerned the vena cava inferior, pulmonary arteries and the thoracic aorta [36]. They originate from the multipotential mesenchymal cells of the internal vascular wall.…”

“…Hattori mentions only 38 cases of primary cardiac leiomyosarcomas [39]. In half of cases they are situated in the left atrium [36], resulting in frequent diagnostic confusion with the most common primary cardiac tumor, myxoma. Additionally, the differentiation is complicated by a myxomatous echocardiographic image.…”

“…However, intraoperative evaluation of the structure according to its coherence, tendency to defragmentation or infiltration of the base should raise some suspicions and lead to intraoperative frozen examination. Pericardial effusion as a sign of malignancy can be absent due to adhesion of the plaques [36]. …”

“…The presence of abundant, myxomatous stroma may suggest a myxoma. With tumor progression, the histopathological picture with enlarging cellularity, mitotic activity and fields of dedifferentiation to osteo- or chondrosarcoma begins to be pathognomonic for malignancy [36, 42]. The diagnosis is confirmed by positive immunohistochemical reactions with SMA, desmin and vimentin, and, if there are other doubts, electron microscopy.…”