Cardiac myxoma is one of the most common primary cardiac neoplasms in adults, second only to papillary fibroelastomas (1). Patients with cardiac myxomas can present with a variety of symptoms such as chest pain, shortness of breath, palpitations, and embolic phenomena. Malaise or syncope was reported in 14% of patients in a case series describing 112 cases of left atrial myxoma (2).

Cardiac myxomas usually (>90%) occur in an isolated fashion, but rarely, they can also occur in a syndromic context, as part of the Carney complex, an autosomal-dominant condition (3). Cardiac myxomas occurring as part of the Carney complex are termed “syndromic myxomas” and are associated with mutations in PRKAR1A (4). In addition to cardiac myxomas, the syndrome is associated with extracardiac myxomas, endocrinopathy, and spotty skin pigmentation (lentiginoses). Cardiac myxomas occurring in the Carney complex are more likely to occur in atypical (non-left atrial) locations, be multiple, and occur earlier in life. Immunohistochemical staining from our patient's myxoma showed positive results for PRKAR1A, but the patient did not have any dermatological manifestations associated with a Carney complex or a history of other tumors.

Myxomas are often initially diagnosed by echocardiography. The classic presentation is a mobile mass on a stalk arising from the atrial septum. In our patient, a TEE was done prior to surgery to assess hemodynamic function. A cavitated sessile mass arising from the atrial septum was seen. The mass did not have a stalk and exhibited contrast within the body of the tumor. The lack of a stalk from which the tumor arose and its cavitated appearance were atypical for a myxoma, warranting further investigation and planning prior to resection. The mass also extended upward into the right pulmonary veins, which is extremely uncommon. Cardiac MRI (CMRI) often complements echocardiography and offers improved tissue characterization, with cardiac myxomas typically demonstrating hypointensity on T1 images, hyperintensity on T2 images, and little to no perfusion or late enhancement (5). T1- and T2-weighted double-recovery sequences aid tissue characterization. Furthermore, cine cardiac imaging holds great importance in evaluating atrial myxomas because of their high mobility and their tendency to prolapse through the atrioventricular valve during diastole (6). Contrast-enhanced sequences are crucial in distinguishing myxomas from thrombus, as myxomas typically exhibit minimal or nil enhancement during first-pass perfusion, yet display a more heterogeneous enhancement pattern on late gadolinium enhancement (LGE) imaging (7). In our case, the patient's cardiac MRI scan did show findings consistent with those of a myxoma, but it revealed more enhancement than is typical. Cardiac MRI has shown remarkable accuracy in identifying cardiac masses and effectively differentiating between benign and malignant tumors. However, relying solely on MRI has been associated with occasional instances of inaccurate diagnosis. Therefore, adopting a multimodal imaging approach comprising echocardiography, MRI, CT, and possibly positron emission tomography (PET) imaging offers an optimal approach for a comprehensive evaluation and stratification of cardiac masses (8). Given the atypical characteristics and location of our patient's left atrial mass, a CT angiogram with a 3D reconstruction of the heart depicting the mass was requested to guide the diagnosis and surgical planning. The mass was heterogeneously enhancing and polypoid in shape. The mass did not infiltrate or invade surrounding structures. This observation holds considerable significance as it reduces the likelihood of the tumor being a malignant one (9). However, it did extend to the ostium of the right superior pulmonary vein, occluding it during atrial systole. It is hard to ascertain whether the mass was the source of our patient's symptoms, but these findings could potentially explain the patient's orthostatic syncope and dizziness. A case report in the literature describes a patient presenting with syncope and dyspnea, who was found to have a left atrial myxoma extending into and occluding the left pulmonary veins and causing pulmonary infarction (10). However, in our patient, the mass did not extend or occlude the mitral valve, which made it feasible to adopt a robotic approach. Furthermore, the mass received blood supply from the small sinoatrial node branch of the right coronary artery. This was visualized precisely and with high spatial resolution on the 3D-printed model, which also showed the extent of expansion of the mass into the right upper pulmonary veins (Figure 4). The printed model also provided for visualization of the best approach to enter the left atrium without disruption of the mass. A possible implication of this occurrence is the formation of a fistula between the sinoatrial nodal artery and the right atrium after surgical resection of the atrial myxoma. For this reason, special attention should be paid to ligating neovascularized branches feeding myxomas during the surgical procedure (11).

This study described a peculiar and unique presentation of a left atrial myxoma extending into the right upper pulmonary veins. Multimodal imaging, including 3D reconstruction and printing of the heart and mass, guided the diagnostic approach and successful resection of the mass by robotic intervention.