Histopathologic and clinical characterization of cardiac myxoma: review of 53 cases from a single institution

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.

Long-Term Efficacy Analysis of Surgical Resection of 70 Primary Right Heart Tumors

INTRODUCTION

The aim of the study was to investigate the clinical characteristics, surgical treatment, and long-term efficacy of primary right heart tumors.

METHODS

This study is retrospective analysis of the clinical data of 70 patients with primary right heart tumors admitted to our department between 1980 and 2022 (observation group) and 70 patients with left heart tumors during the same period (control group). The surgical treatment was performed under cardiopulmonary bypass after differential diagnosis by echocardiography, cardiac CTA, and PET-CT before the surgery. The perioperative characteristics, recurrence rate, and long-term survival rates of right heart tumor versus left heart tumor were compared.

RESULTS

The most common pathological types of right heart tumors were myxoma (60%), lipoma (8.57%), and papillary elastofibroma (7.14%). During the perioperative period, there were 1 case of systemic embolism in the observation group, compared with 6 in the control group (p = 0.026), 13 cases of malignant tumor in the observation group versus 1 in the control group (p = 0.01). During the follow-up period, there were 15 cases of tumor recurrence and 17 cases of death in the observation group versus 4 (p = 0.002) and 7 in the control group (p = 0.006), comparatively.

CONCLUSION

Compared with left heart tumors, primary right heart tumors had a higher incidence of malignant tumors and a lower risk of systemic embolism during perioperative period. During the follow-up period, primary right heart tumors had a higher rate of tumor recurrence and a lower long-term survival rate.

Clinical characteristics and surgical outcomes of cardiac myxoma: A meta-analysis of worldwide experience

Cardiac myxoma is the most common primary cardiac tumor. However, existing literature mainly consists of single-center experiences with limited subjects. This systematic review aimed to provide data on clinical characteristics and surgical outcomes of cardiac myxoma. We performed a thorough literature search on May 23, 2023 on PubMed, ProQuest, ScienceDirect, Scopus, and Web of Science. The inclusion criteria were English full-text, observational studies, and included >20 subjects. From the search, 112 studies with a total of 8150 patients were included in the analysis. The mean age was 51 years (95 % confidence interval [95%CI] = 49.1-52.3), and the majority were females (64.3 % [95 % CI = 62.8-65.8 %]). The most common clinical manifestation was cardiovascular symptoms. Echocardiography can diagnose almost all cases (98.1 % [95 % CI = 95.8-99.6 %]). Cardiac myxoma was mostly prevalent in left atrium (85.3 % [95%CI = 83.3-87 %]) and predominantly with pedunculated morphology (75.6 % [95%CI = 64.1-84.3 %]). Post-tumor excision outcomes were excellent, with an early mortality of 1.27 % (95 % CI = 0.8-1.8 %), late mortality rate of 4.7 (95 % CI = 2.5-7.4) per 1000 person-years, and recurrence rate at 0.5 (95 % CI = 0.0-1.1) per 1000 person-years. Tumor excision is warranted in a timely manner once the cardiac myxoma diagnosis is established.

When Shortness of Breath Gets Misdiagnosed: Atrial Myxoma Case Report

The vague presentation of an atrial myxoma makes accurate diagnosis difficult. This case report reviews the case of a 54-year-old female who presented to the Emergency Department complaining of shortness of breath and back pain. Prior to her Emergency Department evaluation, she had been given a diagnosis with pneumonia. Upon further evaluation, she was diagnosed with a large left atrial myxoma that was surgically removed via median sternotomy. After recovering from her surgery, the patient had a full resolution of her symptoms. Although the treatment for myxomas has a high success rate of full recovery, the difficulty in diagnosis poses problems for patients and can prolong symptoms due to potential misdiagnosis.

New Onset Cardiac Murmur and Exertional Dyspnea in an Apparently Healthy Child: A Rare Localization of Obstructive Myxoma in the Right Ventricle Outflow Tract without Pulmonary Embolization-A Case Report and Literature Review

Myxomas are slowly growing benign neoplasms which are rare in children. Up to 80% can be located in the left atrium and generate symptoms such as embolism, cardiac failure, fever and weight loss. Rarely, myxomas can be detected in the right ventricle outflow tract, causing arrhythmias, pulmonary emboli and sudden death. We report the case of a 13-year-old healthy child brought to the Emergency Department (ED) of the Children's Hospital Bambino Gesù, Rome, for recent dyspnea, chest pain on exertion and new onset cardiac murmur. Patient underwent medical examination and echocardiogram with the finding of a rounded and lobulated voluminous mass in the right ventricle outflow tract (RVOT) which caused severe obstruction. The contrast computed tomography (CT) scan confirmed the presence of a heterogeneously enhancing soft-tissue mass occupying the RVOT with no evidence of pulmonary embolization. The mass was surgically excised, and the pathologic examination confirmed our suspicion of myxoma. Our experience suggests that myxoma can have mild clinical symptoms, the presentation may be non-specific, and diagnosis can be a challenge Careful examination and a diagnostic imaging workup, primarily with the transthoracic echocardiogram, are needful to make a rapid differential diagnosis and to better manage surgical treatment and follow-up.

Left Atrial Myxoma Presenting as Persistent Dizziness

Cardiac masses are divided into benign tumors and malignant tumors. The tumor can cause valvular obstruction and embolization phenomenon. To elucidate the etiology of cardiac masses, we rely on the use of echocardiograms in combination with the clinical picture of the patient. We describe an interesting case report of a 71-year-old woman who presented with persistent dizziness for one day. MRI brain showed multiple, small, scattered foci of acute infarction. The patient was treated with aspirin and atorvastatin. Transthoracic echocardiography showed a mass in the left atrium. Afterward, the tumor was removed surgically and histopathology was consistent with atrial myxoma.

An enormous right atrial myxoma highlights the role of echocardiography in heart failure pathways: a case report

BACKGROUND

Myxomata are rare, benign, primary tumours of the heart which can present with a variety of symptoms depending on size, location, and mobility. Here, we report a case of enormous right atrial myxoma, obliterating the right atrial and right ventricular cavities presenting with symptoms of heart failure.

CASE SUMMARY

A 66-year-old Caucasian female presented to primary care with symptoms of right heart failure and was found to have elevated N-terminal pro B-type natriuretic peptide of 2829 ng/L (normal value <125 ng/L). The patient was referred for urgent evaluation to the integrated heart failure service at our institution. Echocardiography revealed an enormous mobile mass attached to the right atrial septum, extending into the right ventricle and inferior vena cava measuring 90 × 42 mm. The patient underwent urgent surgical resection. Perioperative transoesophageal echocardiography demonstrated severe tricuspid regurgitation, which was treated with tricuspid annuloplasty ring. The patient made an uneventful recovery and was discharged. Subsequent imaging showed a reduction in right ventricular dimensions and improved systolic function.

DISCUSSION

This case serves to remind us of the critical role of echocardiography in the diagnosis and management of people with breathlessness and raised natriuretic peptides. Therapies for heart failure are guided by ejection fraction, therefore timely and accurate diagnosis is critical. Moreover, as in this case, echocardiography can also identify other features of critical relevance to patient care.

Mechanical Thrombectomy in Embolic Cardiac Myxoma: Case Report and Literature Review

Myxomas are the most common cardiac tumors and present clinically with cardiac manifestations, systemic constitutional symptoms, and embolic events. Posterior circulation involvement occurs in approximately 20 percent of cerebral ischemic events.The endovascular technique is an established life-saving therapy for eligible patients upto 24 hours from symptom onset. However, the role of endovascular management in embolic atrial myxoma remains unknown with no international consensus guidelines for the management of stroke in such patient population. Here, we present a case report of an embolic posterior circulation stroke in a young female treated with mechanical thrombectomy at 23 hours from symptom onset. To the best of our knowledge, this is the first thrombectomy case in posterior circulation with embolism from myxoma. Further workup confirmed an atrial myxoma which was resected. We also review the previous cases with mechanical thrombectomy done in such cases.

Atrial myxomas arise from multipotent cardiac stem cells

Aims

Cardiac myxomas usually develop in the atria and consist of an acid-mucopolysaccharide-rich myxoid matrix with polygonal stromal cells scattered throughout. These human benign tumours are a valuable research model because of the rarity of cardiac tumours, their clinical presentation and uncertain origin. Here, we assessed whether multipotent cardiac stem/progenitor cells (CSCs) give rise to atrial myxoma tissue.

Methods and results

Twenty-three myxomas were collected and analysed for the presence of multipotent CSCs. We detected myxoma cells positive for c-kit (c-kit^pos) but very rare Isl-1 positive cells. Most of the c-kit^pos cells were blood lineage-committed CD45^pos/CD31^pos cells. However, c-kit^pos/CD45^neg/CD31^neg cardiac myxoma cells expressed stemness and cardiac progenitor cell transcription factors. Approximately ≤10% of the c-kit^pos/CD45^neg/CD31^neg myxoma cells also expressed calretinin, a characteristic of myxoma stromal cells. In vitro, the c-kit^pos/CD45^neg/CD31^neg myxoma cells secrete chondroitin-6-sulfate and hyaluronic acid, which are the main components of gelatinous myxoma matrix in vivo. In vitro, c-kit^pos/CD45^neg/CD31^neg myxoma cells have stem cell properties being clonogenic, self-renewing, and sphere forming while exhibiting an abortive cardiac differentiation potential. Myxoma-derived CSCs possess a mRNA and microRNA transcriptome overall similar to normal myocardium-derived c-kit^pos/CD45^neg/CD31^negCSCs , yet showing a relatively small and relevant fraction of dysregulated mRNA/miRNAs (miR-126-3p and miR-335-5p, in particular). Importantly, myxoma-derived CSCs but not normal myocardium-derived CSCs, seed human myxoma tumours in xenograft’s in immunodeficient NOD/SCID mice.

Conclusion

Myxoma-derived c-kit^pos/CD45^neg/CD31^neg CSCs fulfill the criteria expected of atrial myxoma-initiating stem cells. The transcriptome of these cells indicates that they belong to or are derived from the same lineage as the atrial multipotent c-kit^pos/CD45^neg/CD31^neg CSCs. Taken together the data presented here suggest that human myxomas could be the first-described CSC-related human heart disease.

Cardiac Myxomas Show Elevated Native T1, T2 Relaxation Time and ECV on Parametric CMR

Introduction: While cardiac tumors are rare, their identification and differentiation has wide clinical implications. Recent cardiac magnetic resonance (CMR) parametric mapping techniques allow for quantitative tissue characterization. Our aim was to examine the range of values encountered in cardiac myxomas in correlation to histological measurements.

Methods and Results: Nine patients with histologically proven cardiac myxomas were included. CMR (1.5 Tesla, Philips) including parametric mapping was performed in all patients pre-operatively. All data are reported as mean ± standard deviation. Compared to myocardium, cardiac myxomas demonstrated higher native T1 relaxation times (1,554 ± 192 ms vs. 1,017 ± 58 ms, p < 0.001), ECV (46.9 ± 13.0% vs. 27.1 ± 2.6%, p = 0.001), and T2 relaxation times (209 ± 120 ms vs. 52 ± 3 ms, p = 0.008). Areas with LGE showed higher ECV than areas without (54.3 ± 17.8% vs. 32.7 ± 18.6%, p = 0.042), with differences in native T1 relaxation times (1,644 ± 217 ms vs. 1,482 ± 351 ms, p = 0.291) and T2 relaxation times (356 ± 236 ms vs. 129 ± 68 ms, p = 0.155) not reaching statistical significance.

Conclusions: Parametric CMR showed elevated native T1 and T2 relaxation times and ECV values in cardiac myxomas compared to normal myocardium, reflecting an increased interstitial space and fluid content. This might help in the differentiation of cardiac myxomas from other tumor entities.

Mitral valve myxoma presenting with transient ischemic attack: a case report and review of the literature

Background

Myxomas account for approximately half of all primary cardiac neoplasms. Most occur in the left atrium and only rarely are attached to the mitral valve, with just over 30 such cases reported in the literature. These neoplasms can manifest with a combination of obstruction of blood flow, systemic embolization, and constitutional symptoms.

Case Description

We present a case of a 32-year-old African American man presenting at an emergency department with symptoms of a transient ischemic attack. Transesophageal echocardiography identified a mass originating from the posterior leaflet of the mitral valve. The mass was surgically resected and histologically classified as a myxoma. He remained asymptomatic during the course of 5-year surveillance.

Conclusions

Few similar cases have been described in the literature. Here we present a review of the diagnosis and surgical management of this rare presentation for mitral valve myxoma.

[On the histogenesis of cardiac myxoma]

OBJECTIVE

to investigate the morphological and phenotypic features of cardiac myxoma (CM), to discuss argumentative issues on the sources of its growth.

SUBJECTS AND METHODS

The investigation included 176 sporadic and familial myxomas originating from different cardiac chambers (96% from the atria). The histological, ultrastructural, and immunohistochemical features of the cells and vessels of this tumor were studied.

RESULTS

The morphological and phenotypic features of the embryonic endothelium resembling the cells of the primary cardiovascular network were found in the cells and vessels of CM. No signs of other mesenchymal derivatives were detected.

DISCUSSION

The authors anticipate that there is focal cessation of maturation of the embryonic endocardial endothelium and its persistence - hamartia. Postnatal proliferation of embryonic hamartia forms the tumor hamartoma. Differentiated cells may retain the phenotypic (but not morphological) features of closely related cells that have a common precursor.

CONCLUSION

The results of the study have allowed the authors to consider CM to be hamartoma, a monohistioid benign embryonic endocardial endothelioma. Our findings do not exclude the possibility of developing CM from pluripotent mesenchymal cells.

Cell differentiation in cardiac myxomas: confocal microscopy and gene expression analysis after laser capture microdissection

Cardiac myxomas are rare tumors with a heterogeneous cell population including properly neoplastic (lepidic), endothelial and smooth muscle cells. The assessment of neoplastic (lepidic) cell differentiation pattern is rather difficult using conventional light microscopy immunohistochemistry and/or whole tissue extracts for mRNA analyses. In a preliminary study, we investigated 20 formalin-fixed and paraffin-embedded cardiac myxomas by means of conventional immunohistochemistry; in 10/20 cases, cell differentiation was also analyzed by real-time RT-PCR after laser capture microdissection of the neoplastic cells, whereas calretinin and endothelial antigen CD31 immunoreactivity was localized in 4/10 cases by double immunofluorescence confocal microscopy. Gene expression analyses of α-smooth muscle actin, endothelial CD31 antigen, alpha-cardiac actin, matrix metalloprotease-2 (MMP2) and tissue inhibitor of matrix metalloprotease-1 (TIMP1) was performed on cDNA obtained from either microdissected neoplastic cells or whole tumor sections. We found very little or absent CD31 and α-Smooth Muscle Actin expression in the microdissected cells as compared to the whole tumors, whereas TIMP1 and MMP2 genes were highly expressed in both ones, greater levels being found in patients with embolic phenomena. α-Cardiac Actin was not detected. Confocal microscopy disclosed two different signals corresponding to calretinin-positive myxoma cells and to endothelial CD31-positive cells, respectively. In conclusion, the neoplastic (lepidic) cells showed a distinct gene expression pattern and no consistent overlapping with endothelial and smooth muscle cells or cardiac myocytes; the expression of TIMP1 and MMP2 might be related to clinical presentation; larger series studies using also systematic transcriptome analysis might be useful to confirm the present results.

Bi-atrial cardiac myxoma with glandular differentiation: a case report with detailed radiologic-pathologic correlation

Introduction

Myxoma is the most common cardiac benign tumour. While a typical myxoma is generally a straightforward diagnosis, some myxomas have unusual features that can make the diagnosis challenging. Glandular myxomas and metastatic adenocarcinomas, the most common type of metastatic carcinoma to the heart, can have very similar features.

Case presentation

We report a 60-year old man who presented with progressive shortness of breath on exertion. Echocardiography demonstrated a large heterogeneous, cystic left and right atrial mass. He was referred for surgery where a smooth and multilobulated left atrial mass was excised. Histopathological analysis with special stains revealed an unusual form of cardiac myxoma with extensive glandular differentiation.

Discussion

Cardiac myxomas can present with diverse clinical, radiological, and pathological features. Echocardiography is a modality of choice for diagnosis but can also miss small or multiple masses. Cardiac myxoma with glandular features is a rare type of myxoma. In our case, there was extensive glandular differentiation and the echocardiographic appearance provided clues for the unusual features of the tumour, suggesting a potential role for echocardiography in the detection and recognition of this morphologic histologic variation.

Outcomes of Video-assisted Minimally Invasive Cardiac Myxoma Resection

BACKGROUND

Myxomas are the most frequent cardiac tumours. Their diagnosis requires prompt removal. In our centre, for valve surgery we use a minimally invasive approach. Here, we report our experience of cardiac myxoma removal through right lateral mini-thoracotomy (RLMT) with particular focus on its feasibility, efficacy and patient safety.

METHODS

Between February 2006 and January 2017, 30 consecutive patients (aged 66±12.6years, range 35-83 years) underwent atrial myxoma resection through video-assisted RLMT. Percutaneous venous drainage was performed in all patients and direct cannulation of the ascending aorta was performed in 28 out of 30 (93.3%). The diagnosis of atrial myxoma was confirmed by histology.

RESULTS

Complete surgical resection was achieved in all patients. The mean cardiopulmonary bypass (CPB) time was 76.5±40.8minutes and average aortic cross-clamping time was 41.5±29.8minutes. No patient suffered postoperative complications. Five patients (16.7%) received a blood transfusion. Mechanical ventilation ranged from 3 to 51hours (median 6hours), intensive care unit (ICU) stay ranged from 1 to 5days (median 1day). Total hospital length of stay (HLOS) was 5.6±2 days. Home discharge rate was 56.7%. No in-hospital mortality was reported. During follow-up (55.6±32.3 months; range 4-132 months), one tumour recurrence was observed. There were three late non-cardiac deaths. Overall survival was 100%, 85.7% and 85.7% at 1, 5 and 10 years, respectively.

CONCLUSIONS

The use of video-assisted RLMT is an effective and reproducible strategy in all patients requiring expedited surgery for left atrial myxoma, independently of coexisting morbidity such as systemic embolisation or previous surgery. This technique leads to complete tumour resection, prompt recovery, early home discharge and high freedom from both symptoms and tumour recurrence.

Recurrent somatic mutations of PRKAR1A in isolated cardiac myxoma

Background

Cardiac myxomas are benign tumors that commonly arise within the left atria. Familial cardiac myxomas are a part of Carney Complex (CNC), an autosomal dominant multiple neoplasia syndrome caused by germline mutations in PRKAR1A. Seven percent of cardiac myxomas are associated with CNC. To date, the genetic basis of isolated cardiac myxomas (ICM), however, has not been fully elucidated.

Methods

We investigated the genetic profile of ICM using whole exome sequencing (WES). Suspected mutations were confirmed using targeted sanger sequencing. To further examine the presence of PRKAR1A mutations in ICM, we performed targeted sequencing in an additional 61 ICM specimens.

Results

87.5% (7/8) of ICM harbored mutations in PRKAR1A. Three of the 8 ICM harbored biallelic somatic mutations of PRKAR1A, including c.607_610del:p.Leu203fs (pathogenic) + c.C896G:p.Ser299X (pathogenic), c.952delT:p.Leu318fs (pathogenic) + c.769-2 A>G (pathogenic) and c.178-1 G>C (pathogenic) + c. 550+1 G>C (pathogenic). Four of 8 tumors harbored monoallelic PRKAR1A mutations, including c.523_524insG:p.Tyr175_Val176delinsX (pathogenic), c.C920A:p.Ser307X (pathogenic), c.30delG:p.Glu10fs (pathogenic) and c.C289T:p.Arg97X (pathogenic). No identical variants were observed across the 8 ICM samples. Interestingly, none of these variants have been previously described in familial cardiac myxomas. In order to confirm our findings, directed sequencing of 61 ICM specimens was subsequently performed. Sixty-four percent (39/61) of ICMs tumors contained inactivating PRKAR1A mutations.

Conclusion

Our findings suggest that loss-of-function mutations of PRKAR1A may play a vital role in the formation of isolated cardiac myxomas.

Preoperative assessment of mitral valve abnormalities in left atrial myxoma patients using cardiac CT

Background

To retrospectively evaluate mitral valve abnormality in left atrial myxoma patients by using cardiac computed tomography (CT).

Material and methods

Cardiac CT was performed in 56 patients with left atrial myxoma and 50 controls. Tumor and mitral valve characteristics were analyzed. The mitral valve parameters differences were compared between patients with myxoma and controls, myxoma with or without mitral valve obstruction, different obstruction degrees, respectively. Receiver operating characteristic analysis was performed to determine the cut-off values of abnormal mitral valve parameters for myxoma patients. Multiple linear regression, logistic regression models and cox regression analysis were used to determine factors associated with mitral valve abnormalities, mitral obstruction, mitral regurgitation and postoperative recovery, respectively.

Results

Myxoma induced the dilation of mitral valve, with different results among different degrees of obstruction (p<0.001). Mitral valve parameters had relationship with myxoma parameters. The cut-off values for discriminating mitral valve abnormalities in myxoma patients were found. Some significant predictors for mitral obstruction were tumor pedicle-tumor volume and patient age (HR, 0.886-30.811; p = 0.011-0.043). Moreover, the predictor for mitral regurgitation was mitral annulus diameter in diastolic phase (HR, 20.862; 95%CI,1.331-327.100; p = 0.031). Some predictors associated with postoperative recovery of mitral regurgitation were age, mitral annulus area, mitral annulus diameter and mitral valve diameter cutoff value for diastolic phase (HR, 0.001-119.160; p = 0.012-0.028).

Conclusion

Cardiac CT is capable of quantitatively assessing myxoma characteristic and mitral valve abnormality induced by myxoma, thus providing guidance of operative management and postoperative evaluation.

Giant Left Atrial Myxoma Masquerading as Cough-Syncope Syndrome

Left atrial myxomas are the most common type of benign primary cardiac tumor. Patients can present with generalized symptoms, such as fatigue, symptoms from obstruction of the myxoma, or even embolization of the myxoma causing distal thrombosis. We describe a case with several-month duration of syncopal episodes that occurred after coughing and with exertion. Computed tomography of the chest showed a 6.1 cm by 4.5 cm mass in the left atrium, later evaluated with an echocardiogram. Cardiothoracic surgery removed the mass, and it was determined to be an atrial myxoma. It is important for an internist to be able to diagnose an atrial myxoma because of the risks associated with embolization and even sudden death as myxoma can block blood supply from atrium to ventricle.

Guidelines for the Use of Echocardiography in the Evaluation of a Cardiac Source of Embolism

Embolism from the heart or the thoracic aorta often leads to clinically significant morbidity and mortality due to transient ischemic attack, stroke or occlusion of peripheral arteries. Transthoracic and transesophageal echocardiography are the key diagnostic modalities for evaluation, diagnosis, and management of stroke, systemic and pulmonary embolism. This document provides comprehensive American Society of Echocardiography guidelines on the use of echocardiography for evaluation of cardiac sources of embolism. It describes general mechanisms of stroke and systemic embolism; the specific role of cardiac and aortic sources in stroke, and systemic and pulmonary embolism; the role of echocardiography in evaluation, diagnosis, and management of cardiac and aortic sources of emboli including the incremental value of contrast and 3D echocardiography; and a brief description of alternative imaging techniques and their role in the evaluation of cardiac sources of emboli. Specific guidelines are provided for each category of embolic sources including the left atrium and left atrial appendage, left ventricle, heart valves, cardiac tumors, and thoracic aorta. In addition, there are recommendation regarding pulmonary embolism, and embolism related to cardiovascular surgery and percutaneous procedures. The guidelines also include a dedicated section on cardiac sources of embolism in pediatric populations.

Posterior wall as atypical localization of left atrial myxoma : Diagnosis and management

Atrial myxomas are the most common benign cardiac neoplasms. Although the majority occur in the left atrium (LA) and are attached to the interatrial septum (75-80 % of cases), they can arise from any part of the LA and the cardiac chambers. We report the case of a 65-year-old woman who presented with features of worsening dyspnea and persistent headache. During transthoracic echocardiography, a suspected cardiac myxoma was found arising from the posterior wall of the LA.

Extracardiac manifestations of atrial myxomas

Primary cardiac tumors are extremely rare and constitute only about 5% of all cardiac tumors. Cardiac myxomas are noncancerous primary tumors of the heart and constitute about of 50% of all primary heart tumors. Left-sided atrial myxomas are more common than right-sided atrial myxomas. Atrial myxomas can lead to a triad of complications. The most common symptoms are associated with obstruction due to the size and location of the tumor. The next most common symptoms are associated with pulmonary and systemic embolization. Patients may also present with constitutional symptoms. Diagnosis is made via means of transesophageal echocardiography and magnetic resonance imaging. Early diagnosis and surgical resection remain the treatment of choice to prevent complications. Patients usually have a good prognosis after resection.

Current diagnosis and management of cardiac myxomas

Cardiac myxoma is the most common cardiac neoplasm. In the majority of cases, it is isolated (non-syndromic) and located in the left atrium. In up to 10% cases, it is seen in syndromic association with the Carney complex where it is encountered in younger patients, with atypical and multiple locations, such as the right atrium or ventricles, and carries a high risk of recurrence. Imaging is pivotal in the diagnosis, management guidance and surveillance. Surgical excision is the established definitive treatment. Further research should address management strategies in incidentally discovered small myxomas in asymptomatic patients and the role of genetic testing and screening in syndromic myxomas.

Neonatal aortic arch obstruction due to pedunculated left ventricular foetal myxoma

Myxoma in neonatal life are extremely rare. We report a case of a neonate with a pedunculated cardiac tumour arising from the anterolateral left ventricular wall protruding across the left ventricular outflow tract and continuously extending into the distal aortic arch. Surgical removal at 14 days of age via combined transaortic approach and apical ventriculotomy was indicated because of the risk of further compromise of aortic valve function and aortic arch obstruction. Histopathologic examination was consistent with a myxoma.

Systematic Review and Meta-analysis of Prevalence of Coronary Artery Disease in Adult Patients with Cardiac Myxomas

Background: Studies have reported varied prevalence estimates of coronary artery disease (CAD) in cardiac myxoma patients. We performed a systematic review and meta-analysis of observational studies to summarize the point prevalence of CAD in adults with cardiac myxomas. Methods and Results: Two independent investigators searched MEDLINE and LILACS databases using the terms " Myxoma", " Coronary Angiography" and " Coronary Disease" from inception through December 2014 for all relevant studies. We included 6 observational studies. Publication bias was evaluated through Egger's test and Trim and Fill method. A pooled estimate of CAD prevalence with corresponding 95% confidence interval (CI) was calculated based on a random-effects model. The pooled CAD prevalence in adult cardiac myxoma patients was 20.7% with low heterogeneity (I ² = 14.86%). Conclusions: It is a matter of debate if preoperative coronary angiography must be done as a routine procedure. Although coronary disease and angiographically detectable neovascularity can alter surgical management, more studies are needed to evaluate this question.

A giant left atrial myxoma neovascularized from the right coronary artery

Myxomas are benign and the most common tumors of the cardiac muscle (Reynen, 1995). They are predominantly located in the left atrium. Clinical manifestations may vary according to the localization and the size of the myxoma. On the other hand, imaging of a myxoma by contrast dye during coronary angiography is a rare sign, which displays the vascular supply of the tumor. Here, we report the case of a 51-year-old man presenting with presyncope and palpitations due to a giant left atrial myxoma having its vascular supply from the right coronary artery (RCA).

[Histopathological and immunohistochemical features of cardiac myxomas]

Mixomas are the most common primary cardiac tumors with an estimate incidence of 0,5-1 per 10(6) individuals per year. These tumors have generated interest due to their unique location (left side of the atrial septum near the fossa ovalis), variable clinical presentation and undefined histogenesis. Most cardiac myxomas occur sporadically while approximately 10% of diagnosed cases develop as part of Carney complex. This neoplasm is of uncertain histogenesis, however, endothelial, neurogenic, fibroblastic, and cardiac and smooth muscle cells differentiation has been proposed, and rarely glandular differentiation has been observed. Recently, due to the expression of certain cardiomyocyte-specific factors, an origin of mesenchymal cardiomyocytes progenitor cells has been suggested. Histologically cardiac myxomas are mainly composed of stellated, fusiform and polygonal cells, immersed in an amorphous myxoid matrix. Immunohistochemically some endothelial markers, such as CD31, CD34, FVIIIAg, are present. Positive staining has also been reported for S-100 protein, calretinin, vimentin, desmin, smooth muscle myosin, CD56, α1 antitrypsin and α 1antichymotrypsin. Surgical resection is currently the only treatment of choice. We present in this article a histopathological and immunohistochemical review of cardiac myxomas.

Molecular basis of cardiac myxomas

Cardiac tumors are rare, and of these, primary cardiac tumors are even rarer. Metastatic cardiac tumors are about 100 times more common than the primary tumors. About 90% of primary cardiac tumors are benign, and of these the most common are cardiac myxomas. Approximately 12% of primary cardiac tumors are completely asymptomatic while others present with one or more signs and symptoms of the classical triad of hemodynamic changes due to intracardiac obstruction, embolism and nonspecific constitutional symptoms. Echocardiography is highly sensitive and specific in detecting cardiac tumors. Other helpful investigations are chest X-rays, magnetic resonance imaging and computerized tomography scan. Surgical excision is the treatment of choice for primary cardiac tumors and is usually associated with a good prognosis. This review article will focus on the general features of benign cardiac tumors with an emphasis on cardiac myxomas and their molecular basis.

Clinical and histopathological analysis of 66 cases with cardiac myxoma

BACKGROUND AND PURPOSE

Cardiac myxoma is a major primary heart tumor which often causes unexpected symptoms or sudden death. This present study was designed to investigate its clinical pathological features and biological behavior.

METHODS

A retrospective analysis of the clinical pathologic and immunohistochemical features of 66 cases with cardiac myxoma was conducted.

RESULTS

In 66 patients with cardiac myxoma, 61 cases had involvement of the left atrium, one case in both the right ventricular and left atria. The female: male ratio was 2.7:1. Patients had symptoms of blood flow obstruction and systemic alterations with performance of arterial embolization. Tumors were spherical, lobulated or irregular in shape, and soft and brittle. Immunohistochemical markers of vimentin and CD34 in tumor cells were positive.

CONCLUSION

Cardiac myxoma always exists in the left atrium and is more common in women, with diverse clinical manifestations and pathomorphism. Although proliferative activity and the recurrence rate are low, in addition to thorough surgical resection, strengthened review is important for young patients.

Clinicopathologic analysis of cardiac myxomas: Seven years' experience with 61 patients

OBJECTIVE

Cardiac myxomas are the most common primary neoplasms of heart. The present study was performed on the 61 cases of patients with cardiac myxoma, in order to investigate the tumors' clinical and pathological features, and to identify the relationship between the pathological characteristics and clinical behaviors.

METHODS

A total of 61 cardiac myxoma cases were analyzed and reviewed retrospectively, including the clinical presentations, physical examinations, and echocardiography, electrocardiography, and pathology documents.

RESULTS

The total patient cohort was made up of 37 women and 24 men. The average age at diagnosis was 48.8 years in males and 51.9 years in females. The most common complaint was dyspnea (37 cases, 60.7%) and the most common sign was systolic murmur (30 cases, 49.2%). Two surface structures and three tumor cell arrangement patterns were observed, and statistical analysis revealed the surface structure was related to the cell arrangement pattern. However, neither the cell arrangement pattern nor the tumor surface structure showed a significant correlation with the clinical presentation.

CONCLUSIONS

The present study showed the pathological profiles of cardiac myxomas were not related to the clinical presentations. The results of our study indicate morphologic classifications of cardiac myxomas may not be significant for clinical practice.

Telocytes are the common cell of origin of both PEComas and GISTs: an evidence-supported hypothesis

We advance the hypothesis that the telocyte might be the cell of origin of both PEComas (perivascular epithelioid cell tumours) and GISTs (gastro-intestinal and extra-gastrointestinal stromal tumours). The hypothesis is supported by data from the literature reporting that both PEComas and GISTs, as well as telocytes, share the expression of several markers. These data were supplemented by original immunohistochemical tests on selected series. Specifically: (1) Melanoma markers (Melan A, MiTF) typical of PEComas are expressed by a substantial fraction of GISTs. A fraction of GISTs was also found positive for CD63, a tetraspanin protein originally described in melanomas and marking exosomes. (2) c-KIT (CD117), proper of the vast majority of GISTs, can be expressed by PEComas (as well as by telocytes). (3) Markers described in telocytes (CD34, S-100, smooth muscle actin and vascular endothelial growth factor) have been reported as positive in cases of PEComas and GISTs. Telocytes show distinctive ultrastructural features with thin, extended, telopodes and are likely involved in inter-cellular signalling via paracrine secretion as well as by shed vesicles and exosomes. These cells have been described in many locations (cavitary and non-cavitary organs) and might display potentialities of a wide spectrum of differentiation (and function). In conclusion we propose that telocytes could be the common cells of origin for both PEComas and GISTs.

Mucin-producing adenocarcinoma arising in an atrial myxoma

We describe the unique autopsy findings of a patient who died of a metastasizing giant right atrial adenocarcinoma containing few areas of typical myxoma. That no mucin-producing extracardiac tumor was detected pointed to the atrial adenocarcinoma as being the primary. We hypothesize that the adenocarcinoma may have developed from coexistent bland glandular structures within the myxoma.

Reversible pulmonary hypertension in adolescent with left atrial myxoma

We report a patient of left atrial huge myxoma presenting with severe pulmonary hypertension in adolescents. A patient was a 14-year-old boy presented with sudden onset dyspnea. Transthoracic echocardiographic study revealed the presence of a nodular, 4.34 × 8.11 cm sized, mobile, hyperechoic mass in the left atrium and severe pulmonary hypertension with tricuspid insufficiency. After surgical therapy, tricuspid regurgitation and pulmonary hypertension was decreased and the patient was stabilized and had an uneventful clinical course.

A large left atrial myxoma detected in emergency department using bedside transthoracic echocardiography

We present a case of a 55-year-old woman with episodes of recurrent pulmonary edema that was diagnosed to have a large left atrial myxoma using bedside transthoracic echocardiography. This case illustrates the importance of a screening focused ultrasound examination of involved systems by emergency physicians in detecting causes for emergency clinical presentations.

Familial recurrent atrial myxoma: Carney's complex

We report on a family of 4 members, all of whom have had multifocal, recurrent atrial myxomas associated with skin pigmentation, melanotic schwannomas, mucocutaneous myxomas, and tumors of the ovary and pituitary, adrenal, and thyroid glands. Immunochemistry of the myxoma cells is positive for calretinin, confirming their neuroendocrine origin. Genetic studies confirmed mutations in the gene coding protein kinase A, regulatory subunit 1-α (PRKAR1α). This is Carney's complex, characterized by multiple, mucocutaneous myxomas; pigmented lesions over the lips, conjunctiva, and genitalia; adenomas of the breast and thyroid; schwannomas; and endocrinal abnormalities including Cushing syndrome and acromegaly. Members of the family require vigorous screening, including urinary free cortisol, plasma transforming growth factor-β(1) and thyrotropin-releasing hormone, testicular ultrasound, routine echocardiographic screening, searches for cardiac and mucocutaneous myxomas in multiple locations, and genetic studies for the PRKAR1α gene sequence.

The Fas-mediated apoptotic pathway in cardiac myxoma

Cardiac myxoma is the most common primary tumor of the heart. The existence of apoptosis in cardiac myxoma has been demonstrated. The purpose of this investigation was to elucidate the pathway of apoptosis and the cell cycle in cardiac myxomas. This study had 2 parts: investigation of a cultured cardiac myxoma cell line and the analysis of data from 20 patients with cardiac myxoma that was surgically excised. Apoptosis signal transduction was determined by assessing DNA fragmentation, Fas ligand (FasL), Fas, tumor necrosis factor-α (TNF-α), caspase-3, and terminal deoxynucleotidyl transferase nick-end labeling (TUNEL) assay through immunohistochemical stain, quantitative reverse transcriptase- polymerase chain reaction (RT-PCR), and Western blot analysis. The patient population consisted of 12 (60%) women and 8 (40%) men with a mean age of 46 years (range = 32-64 years). All cases of myxoma were sporadic myxomas rather than familial. Clinical presentations included asymptomatic (26%), dyspnea (44%), stroke (9%), chest pain (9%), and fever (11%). All myxomas were located in the left atrium. Pathological scores for inflammation, cellularity, calcification, and thrombosis were not related to myxoma location or clinical events. In cardiac myxoma, apoptosis documented by TUNEL (70.9% ± 17.6%) and the caspase-3 (66.5% ± 32.5%) final common pathway is characterized by the extrinsic Fas/ FasL dependent pathway (positive stained 70.9% ± 19.2%; 26.0% ± 17.2%, respectively), but not the intrinsic pathway. The RT-PCR and Western Blot analysis (Fas/FasL, TNF-α, caspase-3, and apoptosis) of the cardiac myxoma and cultured cardiac myxoma cells confirmed the immunochemical results. The extrinsic Fas/FasL-dependent apoptosis pathways in cardiac myxomas were proved by both RNA and protein levels.