Multimodality Imaging of Cardiac Myxomas.

Cardiac myxomas are the most common benign cardiac neoplasms. Echocardiography is the first-line imaging modality used to analyze cardiac masses, allowing the detection of tumor location, size, and mobility. However, additional imaging techniques are required to confirm the diagnosis, evaluate tissue characteristics of the mass, and assess potential invasion of surrounding structures. Second-line imaging includes cardiac magnetic resonance imaging (MRI) and/or computed tomography (CT) depending on availability and the patient's characteristics and preferences. The advantages of CT include its wide availability and fast scanning, which allows good image quality even in patients who have difficulty cooperating. MRI has excellent soft-tissue resolution and is the gold standard technique for noninvasive tissue characterization. In some cases, evaluation of the tumor metabolism using 18F-fluorodeoxyglucose positron emission tomography with CT may be useful, mainly if the differential diagnosis includes primary or metastatic cardiac malignancies. A cardiac myxoma can be identified by its characteristic location within the atria, typically in the left atrium attached to the interatrial septum. The main differential diagnoses include physiological structures in the atria like crista terminalis in the right atrium and the coumadin ridge in the left atrium, intracardiac thrombi, as well as other benign and malignant cardiac tumors. In this review paper, we describe the characteristics of cardiac myxomas identified using multimodality imaging and provide tips on how to differentiate myxomas from other cardiac masses.

Right atrial cardiac myxoma with malignant transformation to undifferentiated sarcoma: A case report.

Generally, sarcomas arising from benign soft tissue are rare. Cardiac myxoma (CM) is a benign tumor, and few reports have described its malignant transformation. Herein, we documented a case of an 89-year-old man with prostate cancer and a five-year history of a right atrium tumor without Carney complex. The tumor was resected surgically and had a myxomatous or gelatinous appearance. Microscopically, the tumor had two components: a sarcomatous area and myxomatous area. In the myxomatous area, typical myxoma cells were demonstrable and were strongly immunoreactive for immunohistochemistry (IHC) of calretinin. In the sarcomatous area, the epithelioid- to spindle-shaped cells with prominent atypia proliferated densely. The IHC profile of cells in the sarcomatous area was different from that of cells in the myxomatous area; MDM2-positive cells were found only in the sarcomatous area. Especially, the Ki-67 index and number of p53-positive cells in the sarcomatous area were higher than those in the myxomatous area. The transition of the two components was seamless. Thus, we made a diagnosis of CM with malignant transformation corresponding to undifferentiated pleomorphic sarcomas. This case suggests that CM may transform into sarcoma, albeit rarely.

Two cases of atrial myxoma with calcification and ossification as the main features.

BACKGROUND: Cardiac myxomas are the most common type of primary cardiac tumors in adults, but they can have variable features that make them difficult to diagnose. We report two cases of atrial myxoma with calcification or ossification, which are rare pathological subgroups of myxoma. CASE PRESENTATION: A 47-year-old woman and a 35-year-old man presented to our hospital with different symptoms. Both patients had a history of chronic diseases. Transthoracic and transesophageal echocardiography revealed a mass in the left or right atrium, respectively, with strong echogenicity and echogenic shadows. The masses were suspected to be malignant tumors with calcification or ossification. Contrast transthoracic echocardiography(cTEE) showed low blood supply within the lesions. The patients underwent surgical resection of the atrial mass, and the pathology confirmed myxoma with partial ossification or massive calcification. CONCLUSION: We report two rare cases of atrial myxoma with calcification or ossification and analyze their ultrasonographic features. Transthoracic echocardiography and cTEE can provide valuable information for the diagnosis and management of such mass. However, distinguishing calcification and ossification in myxoma from calcification in malignant tumors is challenging. More studies are needed to understand the pathogenesis and imaging characteristics of these myxoma variants.

Complex decision making in a patient with lung cancer with incidentally found fast-growing atrial mass.

Atrial myxomas are typically found in the left atrium and are the most common among overall rare cardiac tumors. Herein, we describe the clinical course of a 72-year-old female with non-small cell lung adenocarcinoma found to have an atrial mass during an imaging for evaluation for lung cancer progression. Differentiating between distinct types of masses can pose a challenge to the treatment team especially in the setting of exiting malignancy. This case demonstrates the complex decision making involved in the diagnosis, and timing of intervention to remove atrial mass in patients with frailty and a fast-growing cardiac mass.

10× single-cell sequencing revealed cellular composition heterogeneity in cardiac myxoma with malignant glandular properties.

Cardiac myxoma is the most common primary cardiac tumor in adults. The histogenesis and cellular composition of myxoma are still unclear. This study aims to reveal the role of myxoma cell components and their gene expression in tumor development. We obtained single living cells by enzymatic digestion of tissues from 4 cases of surgically resected cardiac myxoma. Of course, there was 1 case of glandular myxoma and 3 cases of nonglandular myxoma. Then, 10× single-cell sequencing was performed. We identified 12 types and 11 types of cell populations in glandular myxoma and nonglandular myxoma, respectively. Heterogeneous epithelial cells are the main components of glandular myxoma. The similarities and differences in T cells in both glandular and nonglandular myxoma were analyzed by KEGG and GO. The most important finding was that there was active communication between T cells and epithelial cells. These results clarify the possible tissue occurrence and heterogeneity of cardiac myxoma and provide a theoretical basis and guidance for clinical diagnosis and treatment.

Cardiac myxoma and cerebral vasculitis: Is there a link?

BACKGROUND: Cardiac myxomas present a diagnostic challenge due to their ability to mimic various cardiovascular and systemic conditions. Timely identification is crucial for implementing surgical intervention and averting life-threatening complications. CASE PRESENTATION: We reported the case of a 49-year-old male patient who presented sudden legs weakness and slurred speech and was admitted 10 h later in emergency department. Physical examination was significant for paraparesis and paraphasia. Cardiac and carotid auscultation was normal. CT brain revealed multiple acute ischemic strokes and MRA was suggestive of cerebral vasculitis. As pre-therapy assessment, the EKG revealed no electrical abnormalities and the chest X-ray showed signs of left atrial enlargement. Transthoracic and transesophageal echocardiography showed a left atrial mass attached to the interatrial septum, measuring 9*5*4 cm and extending into the left ventricular cavity during diastole, which suggested the diagnosis of left atrial myxoma. The patient was referred for open-heart surgery and histopathological examination confirmed the diagnosis of myxoma. The patient weaned off from cardiopulmonary bypass and the postoperative period was uneventful. CONCLUSION: We reported an interesting case with an unusual and misleading neurological presentation of a cardiac myxoma. The unpredictability of serious complications occurrence must awaken our medical flair, for an early diagnosis among a long list of differentials.

Two cerebral infarctions caused by thrombus and myxomatous embolus in a patient with cardiac myxoma: A case report.

An increasing number of cases of cerebral embolism caused by cardiac myxoma have been reported. However, cerebral infarction caused by different types of emboli obstructing different vascular regions within a short period of time has not been reported. This is the first report to histologically confirm cerebral infarctions independently caused by thrombus and myxomatous embolus in a patient with cardiac myxoma within a period of 23 days. The first cerebral infarction was due to embolization of thrombus to the right middle cerebral artery, whereas the second was due to embolization of tissue from a mucinous tumor to the left middle cerebral artery. Both cerebral infarctions underwent mechanical thrombectomy, but unfortunately, we ultimately failed to save the patient's life. Therefore, further attention should be paid to the surgical resection and treatment of cardiac myxoma.

Renal Embolism Associated with the Atrial Myxoma: A Case Report and Literature Review.

Renal embolisms due to cardiac myxomas are extremely rare; the clinical course, treatment, and prognosis of this disease are not established. A 69-year-old Japanese woman who underwent a nephrectomy for renal cell carcinoma 3 years earlier was hospitalized with a right occipital lobe cerebral infarction. Her renal function suddenly worsened 3 days post-admission: her serum creatinine rose from 1.46 mg/dL to 6.57 mg/dL and then to 8.03 mg/dL the next day, and hemodialysis therapy was started. Abdominal computed tomography (CT) scans showed patchy non-contrasted low-density areas in the right kidney, and chest CT scans and transesophageal ultrasonography revealed a left atrial tumor. We diagnosed renal infarction due to a left atrial myxoma. Hemodialysis and anticoagulant therapy (heparin) were continued, followed by the cardiac myxoma's resection. The patient's renal function gradually improved post-surgery, and the hemodialysis was discontinued. Considering our patient and 19 other case reports of renal infarction associated with cardiac myxoma, the treatment for such a renal infarction and the outcomes differ depending on the embolus site. The poor outcome of abdominal aortic embolism requires a prompt embolectomy, whereas a branch renal artery embolism requires anticoagulation therapy to prevent thrombosis formation around the myxoma.

A Rare Case of Cardiac Myxoma With Moyamoya Phenomenon: A Disease or Syndrome?

Moyamoya disease (MMD) is a rare, idiopathic, progressive, obstructive, vasculopathy affecting primarily the terminal portions of the intracerebral internal carotid arteries, typically at the base of the brain. It is more commonly seen in people of East Asian descent. The moyamoya phenomenon refers to the characteristic appearance of the tangle of fine blood vessels, also described as a puff of smoke. Moyamoya syndrome (MMS) refers to the constriction-induced chronic brain ischemia that is believed to cause overexpression of proangiogenic factors, creating a fragile network of collateral capillaries. MMS refers to the moyamoya phenomenon in the presence of other congenital or acquired disorders. Intracerebral hemorrhage is the leading cause of death for MMS patients. Overall, the prognosis is variable. Cardiac myxoma can cause embolization of tumor cells, plaques, and thrombus, and recurrent thromboembolism can lead to chronic brain ischemia, which can lead to the development of collaterals. There have been cases reported where the moyamoya phenomenon resolved following myxoma resection. Here, we present the case of a female who had intraventricular bleeding and was diagnosed with MMD. Eighteen months later, she presented with shortness of breath and was diagnosed with cardiac myxoma with multiple valvular regurgitations. The myxoma was surgically removed.

Management of left atrial myxoma in pregnant women: a case series.

BACKGROUND: Left atrial myxoma during pregnancy is rare. We present three cases in order to aid in the management. CASE PRESENTATION: Three cases of left atrial myxoma during pregnancy were presented in this article. Three patients all received multidisciplinary team work and acquired good outcomes. The case 1 had no symptoms and delivered before traditional cardiac surgery. The case 2 and case 3 undergone totally endoscopic minimally invasive cardiac surgery during pregnancy. The case 3 maintained pregnancy to term and gave birth to a healthy baby via vaginal delivery. No relapse of the tumor was observed. CONCLUSIONS: The management of left atrial myxoma during pregnancy ought to be individualized and combined with the gestational age. If the diagnosis was made in the first two trimesters of pregnancy, totally endoscopic minimally invasive cardiac surgery during pregnancy would be an optimal choice. The patients can benefit from the multidisciplinary team work.

Pulmonary embolism from right ventricular myxoma in a child with undiagnosed Carney complex.

Pediatric pulmonary embolism occurs in 8.6-57 per 100,000 hospitalised children. We report a novel case of bilateral pulmonary emboli in a child presenting with dyspnoea who was found to have large right ventricular myxoma and subsequent diagnosis of Carney complex. After resection of the right ventricular myxoma and bilateral pulmonary embolectomy, she had a full recovery and an excellent outcome.

Frequent protein kinase A regulatory subunit A1 mutations but no GNAS mutations as potential driver in sporadic cardiac myxomas.

PURPOSE: Cardiac myxomas (CMs) are the second most common benign primary cardiac tumors, mainly originating within the left atrium. Approximately 5% of CM cases are associated with Carney Complex (CNC), an autosomal dominant multiple neoplasia syndrome often caused by germline mutations in the protein kinase A regulatory subunit 1A (PRKAR1A). Data concerning PRKAR1A alterations in sporadic myxomas are variable and sparse, with PRKAR1A mutations reported to range from 0% to 87%. Therefore, we investigated the frequency of PRKAR1A mutations in sporadic CM using next-generation sequencing (NGS). Additionally, we explored mutations in the catalytic domain of the Protein Kinase A complex (PRKACA) and examined the presence of GNAS mutations as another potential driver. METHODS AND RESULTS: This study retrospectively collected histological and clinical data from 27 patients with CM. First, we ruled out the possibility of underlying CNC through clinical evaluations and standardized interviews for each patient. Second, we performed PRKAR1A immunohistochemistry (IHC) analysis and graded the reactivity of myxoma cells semi-quantitatively. NGS was then applied to analyze the coding regions of PRKAR1A, PRKACA, and GNAS in all 27 cases. Of the 27 sporadic CM cases, 13 (48%) harbored mutations in PRKAR1A. Among these 13 mutant cases, six displayed more than one mutation in PRKAR1A. Most of the identified mutations resulted in premature stop codons or affected splicing. In PRKAR1A mutant CM cases, the loss of PRKAR1A protein expression was significantly more common. In two cases with missense mutations, protein expression remained preserved. Furthermore, a single mutation was detected in the catalytic domain of the protein kinase A complex, while no GNAS mutations were found. CONCLUSION: We identified a relatively high frequency of PRKAR1A mutations in sporadic CM. These PRKAR1A mutations may also represent an important oncogenic mechanism in sporadic myxomas, as already known in CM cases associated with CNC.

Simultaneous surgical repair of a cardiac myxoma causing left ventricular outflow tract obstruction and a ventricular septal defect in a small dog.

Background: Cardiac myxomas are benign tumours that can occur in any heart chamber or valve. They are extremely rare in dogs. We present a novel case involving a cardiac myxoma in the left ventricular outflow tract (LVOT) and a ventricular septal defect (VSD) in a small dog. Case Description: A female miniature dachshund (age, 7 months; weight, 2.88 kg) presented with growth insufficiency, lethargy, and a cardiac murmur. Echocardiography revealed a small polypoid mass in the LVOT and a membranous VSD. Simultaneous surgeries were performed to resect the mass (aortotomy) and close the VSD (right atriotomy) using low-flow cardiopulmonary bypass with surface-cooling hypothermia and retrograde cardioplegia. The tumour was histopathologically identified as a myxoma. The dog survived with no cardiac complications for 11 years after surgery. Conclusion: To our knowledge, this is the first report of ante-mortem diagnosis and simultaneous surgical repair of a cardiac myxoma obstructing the LVOT and a VSD in a small-breed dog. In addition to describing this complicated case, this report presents what we believe is the first reported use of retrograde cardioplegia during open-heart surgery in a small-breed dog.

Large Right Atrial Myxoma: A Rare Presentation.

We present a case of a 74-year-old female with a large right atrial myxoma who initially presented to her primary care physician with nonspecific constitutional and abdominal symptoms. Her presenting symptoms were initially thought to originate from her gastrointestinal tract, but her workup for a gastrointestinal disorder was nondiagnostic. It was not until this patient developed symptoms of overt right heart failure that a cardiac condition was suspected. Our case highlights the importance of understanding the potential of cardiac myxomas to mimic many diseases, including cardiac, infective, neurologic, immunologic, pulmonary, and malignant diseases. Therefore, clinicians must always maintain a high index of suspicion for cardiac myxomas when evaluating patients with cardiac and non-cardiac-related symptoms that may be due to these tumors.

Resolving the heterogeneous tumour microenvironment in cardiac myxoma through single-cell and spatial transcriptomics.

BACKGROUND: Cardiac myxoma (CM) is the most common (58%-80%) type of primary cardiac tumours. Currently, there is a need to develop medical therapies, especially for patients not physically suitable for surgeries. However, the mechanisms that shape the tumour microenvironment (TME) in CM remain largely unknown, which impedes the development of targeted therapies. Here, we aimed to dissect the TME in CM at single-cell and spatial resolution. METHODS: We performed single-cell transcriptomic sequencing and Visium CytAssist spatial transcriptomic (ST) assays on tumour samples from patients with CM. A comprehensive analysis was performed, including unsupervised clustering, RNA velocity, clonal substructure inference of tumour cells and cell-cell communication. RESULTS: Unsupervised clustering of 34 759 cells identified 12 clusters, which were assigned to endothelial cells (ECs), mesenchymal stroma cells (MSCs), and tumour-infiltrating immune cells. Myxoma tumour cells were found to encompass two closely related phenotypic states, namely, EC-like tumour cells (ETCs) and MSC-like tumour cells (MTCs). According to RNA velocity, our findings suggest that ETCs may be directly differentiated from MTCs. The immune microenvironment of CM was found to contain multiple factors that promote immune suppression and evasion, underscoring the potential of using immunotherapies as a treatment option. Hyperactive signals sent primarily by tumour cells were identified, such as MDK, HGF, chemerin, and GDF15 signalling. Finally, the ST assay uncovered spatial features of the subclusters, proximal cell-cell communication, and clonal evolution of myxoma tumour cells. CONCLUSIONS: Our study presents the first comprehensive characterisation of the TME in CM at both single-cell and spatial resolution. Our study provides novel insight into the differentiation of myxoma tumour cells and advance our understanding of the TME in CM. Given the rarity of cardiac tumours, our study provides invaluable datasets and promotes the development of medical therapies for CM.

Left atrial myxoma as a rare cause of stroke.

Cerebrovascular events may attribute to the fragmentation of a cardiac tumor. Due to the small number of reported cases of large vascular occlusion-acute ischemic stroke (LVO-AIS) associated with atrial myxoma, current guidelines still follow the principle of intravenous thrombolysis priority, even if LVO-AIS patients are eligible for mechanical thrombectomy, and have not recommended the timing of cardiac surgery or preoperative anticoagulation and antithrombotic therapy. Surgical removal is the definitive therapy for cardiac myxomas, especially for left-sided myxomas. With this case, we aim to demonstrate the main challenges that clinicians may encounter when dealing with patients with AIS secondary to cardiac myxoma: the difficulties with clinical diagnosis, strategies for reperfusion therapy, and therapeutic management of cardiac myxoma.

Cardiac myxomas: causes, presentations, diagnosis, and management.

Cardiac myxomas (CM) are one of the most common benign tumors which are typical in adults with a yearly incidence of 0.5-1 case per million individuals. This review article includes discussions based on existing literature on the role of interleukin interactions in the pathophysiology of cardiac myxoma which can lead to embolic complications, aneurysms, and CNS involvement. The objective of this narrative review was to study the variable clinical presentations of cardiac myxoma, its detection and diagnosis involving multiple modalities like genetic and hematological testing, echocardiography, CT, and MRI, of which transoesophageal echocardiogram shows excellent precision with a 90% to 96% accuracy in diagnosing CM. Individuals with the Carney complex are prone to such neoplasia. Cardiac myxomas are challenging to diagnose due to the ambiguity of their differential with thrombi. Myxomas can also be diagnosed by tumor markers like interleukin-6 and endothelial growth factors. The management of CM includes surgical excision like median sternotomy and robotic minimally invasive surgery. The use of robotic surgery in CM increased from 1.8% in 2012 to 15.1% in 2018. Tumor recurrences are uncommon but can occur due to inadequate surgical resection.

The benign nature and rare occurrence of cardiac myxoma as a possible consequence of the limited cardiac proliferative/ regenerative potential: a systematic review.

BACKGROUND: Cardiac Myxoma is a primary tumor of heart. Its origins, rarity of the occurrence of primary cardiac tumors and how it may be related to limited cardiac regenerative potential, are not yet entirely known. This study investigates the key cardiac genes/ transcription factors (TFs) and signaling pathways to understand these important questions. METHODS: Databases including PubMed, MEDLINE, and Google Scholar were searched for published articles without any date restrictions, involving cardiac myxoma, cardiac genes/TFs/signaling pathways and their roles in cardiogenesis, proliferation, differentiation, key interactions and tumorigenesis, with focus on cardiomyocytes. RESULTS: The cardiac genetic landscape is governed by a very tight control between proliferation and differentiation-related genes/TFs/pathways. Cardiac myxoma originates possibly as a consequence of dysregulations in the gene expression of differentiation regulators including Tbx5, GATA4, HAND1/2, MYOCD, HOPX, BMPs. Such dysregulations switch the expression of cardiomyocytes into progenitor-like state in cardiac myxoma development by dysregulating Isl1, Baf60 complex, Wnt, FGF, Notch, Mef2c and others. The Nkx2-5 and MSX2 contribute predominantly to both proliferation and differentiation of Cardiac Progenitor Cells (CPCs), may possibly serve roles based on the microenvironment and the direction of cell circuitry in cardiac tumorigenesis. The Nkx2-5 in cardiac myxoma may serve to limit progression of tumorigenesis as it has massive control over the proliferation of CPCs. The cardiac cell type-specific genetic programming plays governing role in controlling the tumorigenesis and regenerative potential. CONCLUSION: The cardiomyocytes have very limited proliferative and regenerative potential. They survive for long periods of time and tightly maintain the gene expression of differentiation genes such as Tbx5, GATA4 that interact with tumor suppressors (TS) and exert TS like effect. The total effect such gene expression exerts is responsible for the rare occurrence and benign nature of primary cardiac tumors. This prevents the progression of tumorigenesis. But this also limits the regenerative and proliferative potential of cardiomyocytes. Cardiac Myxoma develops as a consequence of dysregulations in these key genes which revert the cells towards progenitor-like state, hallmark of CM. The CM development in carney complex also signifies the role of TS in cardiac cells.

Mixoma cardiaco como causa de isquemia en niños. Reporte de casos

El mixoma cardiaco constituye uno de los tumores benignos más frecuentes entre los tumores cardiacos. El mismo se caracteriza por la obstrucción del flujo sanguíneo por trombosis o émbolo, resultando en causa de insuficiencia cardiaca con disfunción ventricular, síncope ortostático, isquemia de diferentes órganos de acuerdo a la arteria afectada, e incluso muerte súbita. Presentamos 2 casos en pacientes pediátricos: el primer caso, una adolescente con ACV isquémico y el segundo caso se trata de un adolescente con isquemia a nivel de miembros inferiores por una tromboembolia en la Aorta distal. En ambos casos se realizó la exéresis del tumor, con éxito.

Cardiac myxoma is one of the most frequent benign tumors among cardiac tumors. It is characterized by the obstruction of blood flow due to thrombosis or embolus, resulting in heart failure with ventricular dysfunction, orthostatic syncope, ischemia of different organs depending on the affected artery, and even sudden death. We present 2 cases in pediatric patients: the first case, an adolescent with ischemic stroke and the second case is an adolescent with ischemia in the lower limbs due to a thromboembolism in the distal aorta. In both cases, the exeresis of the tumor was performed successfully.