Primary tumors of heart are rare, with an incidence ranging from 0.0017% to 0.03% in reported autopsy series, and the majority are benign [1, 2]. Cardiac myxoma is the most common primary benign cardiac tumor in adults. It is seen more commonly in females with a wide age range from the third to sixth decade . The clinical features and familial history of patients with cardiac myxomas reveal the differences between sporadic and familial cases.
The appearance of a single tumor in the left atrium of middle-aged women, without other coincidental extracardiac manifestations is associated with non- familial or sporadic type of the disorder. On the other hand, the presence of a tumor in the right atrium in the younger age groups with familial predisposition and high incidence of recurrence is considered to be familial cardiac myxoma .
Pateras et al. consider that Herpes simplex virus (HSV) DNA infection is involved in the pathogenesis of sporadic atrial myxoma. The authors note that the presence of HSV-1 and/or −2 DNA was detected in 35% of the informative sporadic cardiac myxomas. Furthermore, they consider that the tropism of the virus for myxomatous endocardium and the viral life cycle remain an issue to be addressed concerning the rate of recurrences of the tumor .
Stratakis claims that, one-fifth of patients with familial myxomas present with extracardiac involvement consisting of a primary pigmented nodular adrenocortical disease, skin lesions - including lentigines, ephelides, blue nevi, cutaneous myxomas, myxoid mammary fibroadenomas, pituitary adenomas, thyroid and testicular tumors and melanotic Schwannomas. At least, two or more of these findings must be present in order to be diagnostic .
Seventy-five percent of the myxomas are located in the left atrium, and 20% in the right atrium, whereas ventricular origination is the most infrequent . According to Pinede et al., the location, size, and mobility of the tumor are related to the clinical symptoms. The cardiac myxomas are located mainly in the left atrium, originating from the atrial septum next to the margin of fossa ovalis. This predilection for the left heart often leads to left-sided congestive heart failure following complete mitral valve obstruction or coronary artery embolism, and systemic embolization occurring in 40% of patients due to small tumor particles or thrombus on the tumor surface .
The cardiac myxomas of the right atrium often lead to right-sided congestive heart failure related to venae cavae obstruction and tricuspid valve disease . The presenting symptoms usually are dyspnea, chest pain, syncope, pulmonary hypertension, and cardiac arrhythmias, however, these symptoms are common in cardiac patients generally. Fever, malaise, weight loss, polymyositis, hepatic dysfunction, Raynaud’s phenomenon, hyperglobulinaemia and arthralgias, are also described in patients with atrial myxomas and attributed to an autoimmune response or a result of a secondary tumor infection . The malignant potential of atrial myxomas remains a matter of debate. Few cases of atrial myxomas with extracardiac metastasis have been described in the literature. On the other hand, some authors believe that chondrosarcomas simulate malignant atrial myxomas .
The echocardiographic appearance is a useful diagnostic tool in early diagnosis, with high sensitivity. The transesophageal and transthoracic echocardiography (TTE) are able to determine tumor size and type (benign or malignant), anatomical localization and valvular abnormalities [2, 5]. CT and MRI have excellent diagnostic advantages regarding tumor delineation and spread. More specifically, MRI currently appears to be the imaging modality of choice in differentiating left atrial myxoma from malignancies .
A long term follow-up is recommended to patients and their first degree siblings, especially, with familial cardiac myxomas. Prognosis is usually favorable with considerable potential for full recovery. However, lethal outcome in unrecognized and untreated cases can also occur due to coronary or cerebral embolization and complete obstruction of mitral or tricuspid valve. Also, the prognosis for patients with Carney syndrome is reserved due to the malignant potential of pituitary, testicular, thyroid and metastasizing pancreatic tumors or melanotic Schwannomas .
The main treatment strategy is surgical resection. In the literature, the recurrence rate is between 1 to 3% for sporadic cases of cardiac myxomas and is increased significantly for patients with familial and Carney complex myxomas, at 12% and 22% respectively . Some authors suggest that treatment with suppressive anti - HSV drugs such as acyclovir for HSV - positive patients postoperatively is beneficial in reducing the rate of recurrences . We consider that anticoagulation treatment in inoperable patients protects against thromboembolic events.
The high incidence of recurrence results for several reasons: incomplete excision of the tumor, implantation of tumor fragments and familial predisposition . An autosomal dominant inheritance of familial and Carney complex is well- documented. Half of the known Carney complex myxomas can be attributed to mutations in PRKAR1A genes .
The performed genetic analysis of our patient disclosed an aneuploid DNA (diploid) content (S = −1.0% and G2 = −1.0%), with 42.9% of cells in the DNA synthetic phase confirming the above assumption. DNA analysis by flow cytometry provides fast results, permits multiparameter analysis, correlating DNA content with antigen expression, and provides the sensitivity for detecting near-diploid aneuploid peaks . Unfortunately, we were not able to obtain our patient’s mother’s biopsies in order to conducted genetic analysis for aneuploidy. Finally, in our case, no potential histopathological differences of the tumor were observed among recurrences.
The role of heart transplantation and auto-transplantation remains unclear and requires additional studies [1, 2, 12, 13].