The Role of Methylation Analysis in Distinguishing Cellular Myxoma from Low-Grade Myxofibrosarcoma.

Cellular myxoma is a benign soft tissue tumor frequently associated with GNAS mutation that may morphologically resemble low-grade myxofibrosarcoma. This study aimed to identify the undescribed methylation profile of cellular myxoma and compare it to myxofibrosarcoma. We performed molecular analysis on twenty cellular myxomas and nine myxofibrosarcomas and analyzed the results using the methylation-based DKFZ sarcoma classifier. A total of 90% of the cellular myxomas had GNAS mutations (four loci had not been previously described). Copy number variations were found in all myxofibrosarcomas but in none of the cellular myxomas. In the classifier, none of the cellular myxomas reached the 0.9 threshold. Unsupervised t-SNE analysis demonstrated that cellular myxomas form their own clusters, distinct from myxofibrosarcomas. Our study shows the diagnostic potential and the limitations of molecular analysis in cases where morphology and immunohistochemistry are not sufficient to distinguish cellular myxoma from myxofibrosarcoma, particularly regarding GNAS wild-type tumors. The DKFZ sarcoma classifier only provided a valid prediction for one myxofibrosarcoma case; this limitation could be improved by training the tool with a more considerable number of cases. Additionally, the classifier should be introduced to a broader spectrum of mesenchymal neoplasms, including benign tumors like cellular myxoma, whose distinct methylation pattern we demonstrated.

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.

[Right Atrial Myxoma After Catheter Ablation:Report of a Case].

An 81-year-old man underwent total arch replacement for thoracic aortic aneurysm 8 years ago and catheter ablation for paroxysmal atrial fibrillation 1 year ago. Transthoracic echocardiography revealed a mass in the right atrium, and the patient was admitted for close examination and treatment. Transesophageal echocardiography revealed a 23×17 mm large well-defined mass above the cavotricuspid isthmus. Two venous drainage cannulas were inserted directly to the superior vena cava and to the inferior vena cava via the right femoral vein, in order to avoid the direct contact with the right atrium prior to institution of cardiopulmonary bypass. The right atrial tumor was found attached to the cavotricuspid isthmus, and was resected together with the right atrial wall. Pathological examination showed myxomatous tissue. Postoperative course was uneventful. He was discharged 23 days after the operation.

A surgical resection case of myxoma arising from the posterior wall of the left atrium complicated with complete atrioventricular block.

An 80-year-old female was referred to our institution due to transient right upper limb weakness. Transthoracic and transesophageal echocardiography revealed a tumor in the left atrium. The tumor was attached to the posterior wall of the left atrium near the atrioventricular node. Intraoperative pathological examination revealed that the tumor was a myxoma, and complete resection was successfully performed. However, she experienced persistent complete atrioventricular block postoperatively and required pacemaker implantation.

All that Doesn't Enhance Isn't a Thrombus: Pitfalls Using Cardiac MRI TI 600 Sequence to Distinguish Between Cardiac Thrombus Versus Myxoma.

A 51-year-old male with a complicated medical history presented with shortness of breath. Preoperative workup confirmed the presence of a large atrial mass. However, delayed gadolinium enhancement CMR with long inversion time (TI 600) showed lack of enhancement, which was suggestive of a thrombus. During cardiac magnetic resonance imaging, delayed gadolinium enhancement sequences with long inversion time (TI 600) are commonly used to distinguish between an avascular thrombus versus a vascular tumor.

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.

Acute ST-Elevation Myocardial Infarction in a Young Adult: Rare Presentation of Giant Atrial Myxoma. / Infarto com Supra-ST em Adulto Jovem: Rara Apresentação de Mixoma Atrial Gigante.

Cardiac tumors are rare entities, among which atrial myxoma (AM) stands as the most frequent, accounting for approximately half of all reported cases. The incidence of AM is estimated to range from 0.001% to 0.3% within the general population, yet only about 0.06% of these cases present with coronary embolic events. We report on a 33-year-old male smoker who experienced acute, severe precordial pain radiating to the left upper limb, lasting for one hour. The electrocardiographic evaluation demonstrated ST-segment elevation in leads D2, D3, and aVF, alongside significantly elevated serum troponin levels, confirming a diagnosis of ST-segment elevation myocardial infarction (STEMI). Subsequent coronary angiography revealed proximal occlusion of the right coronary artery due to thrombus. An initial attempt of thrombus aspiration was unsuccessful, followed by primary angioplasty with balloon inflation without stent placement. Further diagnostic exploration through transthoracic echocardiography identified a homogenous, smooth-surfaced mass measuring 5.2 cm x 2.3 cm attached to the interatrial septum. This mass, characterized by lobulations, prolapsed into the mitral valve and left ventricle during diastole, consistent with AM. Surgical resection of the mass was successfully performed, with the patient being discharged asymptomatic. In the reported case, the patient's profile, notably his age, and gender, diverges from the typical epidemiological characteristics associated with AM. This case adds to the limited number of reports where the inferior wall is affected by the right coronary artery being occluded. This report emphasizes the significance of differential diagnoses in younger patients presenting with STEMI.

Neoplasias cardíacas são raras, tendo como principal representante o mixoma atrial (MA), que corresponde a cerca de metade de todos os casos. O MA tem incidência estimada entre 0.001% e 0.3% na população em geral, no entanto apenas aproximadamente 0,06% desses cursam com eventos embólicos coronarianos. Homem de 33 anos, tabagista, admitido com quadro de precordialgia intensa e irradiação para membro superior esquerdo com duração de uma hora. O eletrocardiograma evidenciou elevação de segmento ST nas derivações D2, D3 e aVF troponina sérica elevada, confirmando infarto com supra desnivelamento do segmento ST (IAMCSST). Foi realizada cineangiocoronariografia, a qual revelou oclusão em terço proximal de artéria coronária direita por trombo. Realizada tentativa de aspiração do trombo, sem sucesso, seguido por angioplastia primária com balão sem colocação de stent. Durante a investigação do quadro, paciente realizou ecocardiograma transtorácico o qual demonstrou massa homogênea de superfície regular, de 5.2 cm x 2.3 cm, aderida ao septo interatrial, com lobulações de características emboligênicas prolapsando para valva mitral e ventrículo esquerdo na diástole, compatível com MA. Foi realizada ressecção cirúrgica com paciente evoluindo assintomático, recebendo alta para seguimento ambulatorial. O caso relatado difere em idade e sexo do perfil epidemiológico típico sendo um dos poucos descritos com acometimento da parede inferior apresentando a artéria coronária direita como culpada. Este relato ratifica a importância do diagnóstico diferencial frente às apresentações de IAMCSST em jovens.

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.

Conjunctival myxoma: A case report and review of a rare tumor.

RATIONALE: Conjunctival myxoma is a rare benign tumor, which can mimic more common conjunctival lesions such as a cyst, lymphangioma, amelanotic nevus, neurofibroma, amelanotic melanoma, or lipoma. We describe a patient with the conjunctival myxoma, who was initially misdiagnosed as a conjunctival cyst. This case report includes intraoperative photographs and various immunohistochemical staining images. PATIENTS CONCERNS: A 55-year-old woman presented with a painless mass in the superotemporal conjunctiva of the left eye, which she had noticed 1 month ago. The patient had no previous history of trauma or eye surgery. Slit-lamp examination revealed a well-circumscribed, freely movable, pinkish, semi-translucent mass on the temporal bulbar conjunctiva, suggestive of a conjunctival cyst. DIAGNOSES: Histopathological analysis showed stellate- and spindle-shaped cells within the loose myxoid stroma, confirming a diagnosis of conjunctival myxoma. INTERVENTIONS: The conjunctival lesion was completely excised under local anesthesia. OUTCOMES: After 4 months of follow-up, the patient remained in good health without recurrence of the conjunctival lesion and no evidence of any systemic abnormality. LESSONS: Myxoma is an extremely uncommon benign tumor derived from primitive mesenchyme. Considering the rarity of the tumor and its similarity to other conjunctival tumors, diagnosis can be challenging. Ophthalmologists should consider myxoma as a possible differential diagnosis when encountering conjunctival lesions. Surgical excision is essential to confirm the diagnosis and careful systemic evaluation is required to prevent potentially life-threatening underlying systemic conditions.

Dizzy spells in pregnancy: successful antenatal removal of a huge left atrial myxoma with mitral valve obstruction.

Diagnosing atrial myxoma in pregnancy is challenging because patients may present with non-specific symptoms that might be overlooked. The timing of non-obstetric operation usually depends on the nature of the disease, after careful consideration of feto-maternal safety, including the use of cardiopulmonary bypass and placental transfer of anaesthetic drug. A woman in her 30s at 18 weeks of pregnancy presented with recurring dizziness. She underwent successful myxoma excision at 20 weeks under general anaesthesia and cardiopulmonary bypass. The 6×5 cm myxoma was histologically confirmed as myxoma. Early detection of atrial myxoma in pregnancy is crucial, and a clinician has to consider the diagnosis of left atrial myxoma with mitral valve obstruction as a cause of severe dizziness. Optimal outcomes require multidisciplinary management. In this case, surgery during the second trimester of pregnancy enabled a full-term pregnancy with the patient's and foetal well-being and normal postprocedural echocardiography.

Carpal Tunnel Syndrome Caused by a Juxta-articular Myxoma: A Case Report.

Juxta-articular myxoma (JAM) is a rare soft tissue tumour predominantly composed of mucinous tissue and usually found around large joints. We report a 73-year-old woman with a 5-year history of a soft tissue mass in the thenar eminence of the right wrist who presented to our department. An initial diagnosis of a ganglion cyst was made using magnetic resonance imaging (MRI) and the jellied content of the mass by aspiration. Two years after presentation, surgical treatment with tumour resection and carpal tunnel release via the radial approach was performed because the symptoms of carpal tunnel syndrome worsened, and the tumour invaded the carpal tunnel. Histopathological examination revealed a JAM. At the 1-year follow-up, the symptoms of carpal tunnel syndrome had resolved, and no recurrence was confirmed by MRI. Level of Evidence: Level V (Therapeutic).

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.

Left atrial myxoma with cardiogenic shock following a myocardial infarction: a case report.

BACKGROUND: Myxomas are the most common primary cardiac tumor and typically originate in the left atrium. Atrial myxomas may present following complications of obstruction and emboli. If an atrial myxoma goes untreated, complications such as congestive heart failure, embolic stroke, and sudden death can occur. CASE PRESENTATION: A 58-year-old Caucasian male presented following a cardiac arrest. He was taken emergently to the cardiac catheterization lab and received two drug eluting stents. Following the procedure, he was found to have a left atrial mass that was intermittently obstructing the mitral valve on echocardiography. After leaving the cardiac catheterization lab, he was hypotensive and placed on multiple intravenous medications for hemodynamic support as well as an Impella device. Following medical optimization, he underwent one vessel coronary artery bypass graft as well as surgical excision of the left atrial mass, which pathology had shown to be an atrial myxoma. CONCLUSION: This patient's case of cardiogenic shock following revascularization was complicated by the identification of an atrial myxoma, which, when large enough, can obstruct blood flow through the mitral valve leading to acute mitral dynamic stenosis. This condition results in circulatory collapse due to obstruction of the left ventricle in diastole as the myxoma occludes the mitral valve.

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.

Our 10-Year Experience with Atrial Myxomas: Is Concurrent Valve Intervention Really Warranted?

INTRODUCTION: Primary cardiac myxomas are rare tumors. Concurrent valvular lesion is a common finding on evaluation which is thought to be due to annular dilatation secondary to tumor movement across the valve, functional obstruction across the valve, and severe pulmonary hypertension secondary to chronic obstruction. A common belief among surgeons is that excision of myxoma leads to abatement of symptoms, and further valve intervention may not be warranted. METHODS: A 10-year retrospective descriptive study was designed to analyze patients who underwent excision of cardiac myxoma at our center. Data was analyzed regarding presenting features, echocardiographic findings of myxoma and valve morphology, intraoperative assessment, and postoperative outcome with/without valve repair/replacement in all patients. RESULTS: A total of 22 patients underwent surgery for myxoma. Six patients underwent successful mitral valve repair with ring annuloplasty, two had moderate mitral regurgitation, three had severe mitral regurgitation, and one patient had no mitral regurgitation on preoperative assessment, but moderate mitral regurgitation was found intraoperatively. Four of these patients had no residual mitral regurgitation in follow-up period while two had mild residual mitral regurgitation. One patient had severe mitral stenosis of concurrent rheumatic etiology and successfully underwent mitral valve replacement. CONCLUSION: Cardiac myxomas are rare benign tumors commonly associated with mitral valve insufficiency. Mitral valve should be assessed intraoperatively after excision of mass as preoperative assessment might often be insufficient. Concomitant mitral valve intervention might be needed with a case-specific tailored approach, and mitral valve repair with ring annuloplasty offers best surgical outcome in such cases.

Vasculitic rash and cerebral emboli in an adolescent with left atrial myxoma.

A previously healthy woman in late adolescence presented to the emergency department with stroke-like symptoms following a two-month history of bilateral foot pain and oedema, accompanied by a macular rash and progressive lower extremity weakness. On further investigation, she was found to have multiple cerebral emboli and a left atrial myxoma fixed to the interatrial septum. The patient subsequently underwent urgent surgical excision of the myxoma. On follow-up, her cutaneous and neurological symptoms were significantly improved. This case suggests that, in the presence of a vasculitic rash without evident or obvious cause, cardiac myxoma should be included in the differential diagnosis.