Cardiac myxomas in an unusual location: A glimpse into their potential characteristics

To the Editor,

In the clinical context, cardiac myxomas mostly emerge in middle-aged women and generally present with a variety of cardiovascular symptoms attributable to their constitutional, obstructive, and embolic manifestations (1, 2). Traditionally, the left atrium (LA) has been the usual predilection site for these benign neoplasms (2, 3). However, atypical locations including left ventricular outflow tract (LVOT) have also been occasionally reported (3). In this context, the recently reported article by Kasmeridis et al. (1) has presented an atypical case of cardiac myxoma within the right ventricular outflow tract (RVOT) in a female patient. Therefore, we would like to make a few comments on this didactic case and the clinical implications of atypical myxoma locations.

First, cardiac myxomas in an unusual location might potentially suggest a familial background and warrant further investigation (2, 4). Importantly, familial cardiac myxomas, besides having a substantial proclivity for unusual cardiac locations, might potentially arise at multiple sites and have a significant risk for future recurrences (2, 4). Of note, these familial neoplasms emerge in isolation or in association with certain clinical entities including Carney’s complex (mainly presenting with cutaneous tumors and endocrine abnormalities) (2, 4). This leads us to ponder about genetic analysis and family history of cardiac myxoma in this case. There is also a question regarding the presence of myxoma syndromes and their clinical manifestations (if any) in the patient.

Second, systemic inflammation has also been considered as a cardinal feature of cardiac myxomas and has been mostly associated with constitutional symptoms (fever, rash, etc.) and tumor embolism (2). More specifically, persistent increments in the levels of certain markers including interleukin-6 were previously suggested to promote local recurrences following myxoma resection (2, 5). Interestingly, persistent systemic inflammation might also account for the evolution of distant myxomatous lesions mostly in the form of central nervous system (CNS) pathologies, including vascular aneurysms and solid parenchymal masses that might also arise as systemic recurrences even several years after the resection of primary cardiac tumor (2). Importantly, possibility of pulmonary recurrences manifesting as multiple parenchymal infiltrations should also be kept in mind in the setting of right-sided myxomas.

Taken together, persistent systemic inflammation might be associated with systemic and local recurrences of cardiac myxomas potentially indicating important clinical implications (mostly regarding prognosis and management strategies including close follow-up, anti-inflammatory strategies, etc.) (2). In this context, these implications seem to be more pronounced in the setting of familial cardiac myxomas (2) (and possibly in cardiac myxomas in an unusual location regardless of their genetic basis). Therefore, we would like to have information on the levels of inflammation markers in the pre and post-surgical settings along with the authors’ future strategy (schedules of clinical visits, echocardiogram along with CNS, pulmonary imaging, etc.) for the timely detection of potential recurrences in this patient.

Finally, cardiac myxomas are also well known to elicit gradual valvular damage in certain settings mostly attributable to their direct impingement on valvular structures (6) during cardiac systole and/or diastole. As expected, valvular impingement during systolic phase is possibly more forceful due to the higher velocity, and therefore kinetic energy of the tumor mass at the time of its collision with valvular structures. In this context, valvular injury during cardiac systole is expected to be encountered predominantly in ventricular myxomas (7). Moreover, it is well known that any significant gradient across the ventricular outflow tracts [which could also be attributable to myxoma obstruction without direct impingement on the valvular structures (8)] generally creates a systolic turbulent jet flow that might eventually lead to structural degeneration in semilunar valves (manifesting as valvular regurgitation and/or stenosis in the longterm). Accordingly, we wonder about the magnitude of RVOT gradient along with the degrees of pulmonary valvular and right ventricular dysfunctions (if any) in the patient. Importantly, secondary valvular degeneration might be potentially overlooked in certain patients with myxoma, potentially warranting detailed examination of valvular functions before myxoma resection.

In summary, cardiac myxomas in an atypical location might potentially suggest a familial background generally indicating a detailed clinical evaluation along with genetic analysis (2, 4). Moreover, clinical relevance of systemic inflammation is possibly more pronounced in these myxomas (compared with classical myxomas involving the LA). Lastly, unusual myxoma locations including LVOT and RVOT (1, 2, 7, 8) might be particularly associated with the dysfunction of semilunar valves that need to be thoroughly evaluated, and where necessary, surgically managed during myxoma resection. However, these notions still need to be further tested in clinical trials.