Cardiac Myxomas Resembling Malignant Neoplasia: Incidentally Diagnosed vs. Cerebral Embolized Myxomas

SIMPLE SUMMARY: Cardiac tumors are relatively rare. Cardiac Myxomas (CM) are considered one of the most common benign cardiac tumors. They are usually distinct from soft tissue myxoma, most often occurring as a solitary, sporadic, pedunculated mass in the left atrium, and approximately 10% are associated with Carney syndrome with a high recurrence rate. They may cause sudden death, usually due to mitral valve obstruction or congestive heart failure. Malignant changes are known to occur but are extremely rare. They may mimic malignant neoplasia because of frequent embolism and can cause neurological deficits before theirsurgical removal. The current study analyzed the outcomes after operative myxoma excision in patients with or without cerebral embolic events prior to excision. ABSTRACT: Background: Cardiac myxomas (CM) are the most common primary cardiac tumors in adults. They are usually benign; however, malignant changes are known to occur but are extremely rare. Embolization is a common complication of cardiac myxomas and can cause neurological deficits before their surgical removal. The current study analyzed the outcomes after operative myxoma excision in patients, with and without cerebral embolic events prior to excision. Methods: All 66 consecutive patients who underwent a surgical excision of CM between 2005 and 2019 at our department were analyzed retrospectively. Patients with (n = 14) and without (n = 52) preoperative strokes caused by cerebral tumor embolization were compared. Results: The mean age was 58.4 ± 12.7 years in the stroke group (SG) and 62.8 ± 11.7 years in the non-stroke group (N-SG) (p = 0.226). Gender (35.7% vs. 61.5% female; p = 0.084) did not differ significantly, and comorbidities were comparable in both groups. The left hemisphere in the territory of the middle cerebral artery was affected by preoperative cerebral infarction most commonly (28.6%). The time from diagnosis to cardiac surgery procedure was 7 (3–24) days in the SG and 23 (5–55) days in the N-SG (p = 0.120). Cardiac myxomas were localized in the left atrium in both groups more frequently (SG: 92.9% vs. N-SG: 78.8%; p = 0.436). In the SG, 57.1% of CM had a non-solid surface, were localized in the left heart, and had a pedunculated attachment away from the fossa ovalis. In the N-SG, 92.3% of CM did not meet all these criteria (p < 0.001). The maximal diameters of CM were comparable (SG: 3.4 ± 1.5 cm vs. N-SG: 3.8 ± 2.1 cm; p = 0.538). The operation times (192.5 (139.3–244.5) min vs. 215.5 (184.5–273.3) min; p = 0.046) and the cross-clamp times (54.5 (33.3–86.5) min vs. 78.5 (55–106.8) min; p = 0.035) were significantly shorter in the SG. Only in the N-SG were reconstructions of the endocardium with bovine pericardium required after resection (51.9% vs 0%; p < 0.001). In the N-SG, CM were explored via the right atrium more often (57.7% vs. 14.3%; p = 0.007). Patients in the N-SG required significantly shorter ICU care after surgery (p = 0.020). Other postoperative courses did not differ significantly. After tumor removal, 1.9% of the N-SG suffered their first stroke and 14.3% of the SG had a cerebral re-infarction (p = 0.111). The 30-day mortality rates were 1.9% in the N-SG and 7.1% in the SG (p = 0.382). In one case in the N-SG, a tumor recurrence was diagnosed. The Kaplan–Meiercurves showed a significantly better long-term prognosis for patients in the N-SG (p = 0.043). Conclusions: After the surgical removal of CM, the outcome is compromised if preoperative cerebral embolization occurs. Surgical treatment is therefore indicated as soon as possible, especially when CM have a non-solid surface, are localized in the left heart, and have a pedunculated attachment away from the fossa ovalis.