Cardiac myxoma is rich in factor XIIIa positive dendrophages: immunohistochemical study of four cases

Cardiac myxoma is an enigmatic tumour thought to arise from primitive cardiac mesenchymal cells. Factor XIIIa+ dendrophages are tissue histiocytes that are active in tissue repair and thrombosis. To explore whether factor XIIIa+ dendrophages play a role in cardiac myxoma morphogenesis, we stained four cases with an antiserum against coagulation factor XIIIa (FXIIIa). We also used antibodies recognizing CD34, CD31, and S-100 protein. Samples of valvular endocardium from 12 and 16 week fetuses and two adult autopsies were compared with the four myxomas. All cardiac myxomas had rounded and dendritic FXIIIa+ cells admixed with more numerous CD34+ spindle and stellate myxoma cells. The CD34+ cells formed multicellular syncytia and capillary sprouts. Many of these syncytial structures also expressed CD31 and, to a lesser extent, S-100 protein, strongly in two cases and more focally in two. Fetal subendocardium was composed of CD34+ stellate fibroblast-like cells invested with scattered FXIIIa+ histiocytes; no S-100+ cells were detected. Our findings confirm that cardiac myxomas are composed of CD34+ primitive subendocardial cells. These cells show a capacity for CD31+ endothelial differentiation. In cardiac myxoma, the CD34+ myxoma cells are accompanied by numerous FXIIIa+ dendrophages, the presence of which suggests abnormal organizing thrombus-like differentiation in cardiac myxoma morphogenesis.     

Immunohistochemical expression of endothelial markers in left atrial myxomas: a study of six cases

Vascular endothelial cells are antigenically heterogeneous and therefore it has been recommended that a range of immunohistochemical markers is employed to show the presence of cells of endothelial origin in surgical pathology. In this study we applied three monoclonal antibodies—to factor VIII-related antigen, JC70 (CD31), QBend 10 (CD34)—and Ulex europaeus agglutinin type 1 lectin (UEA-1), to six consecutive cases of left atrial myxoma. We found that JC70 and QBend 10 consistently stained myxoma cells in all their different growth patterns contrasting with factor VIII-related antigen expression and UEA-1 binding which were restricted to areas which showed morphological evidence of vascular differentiation. These findings suggest that the constituent cells of atrial myxomas show more widespread endothelial differentiation than has previously been recognized and that differences in immunohistochemical staining may reflect the maturation status of these cells.     

Left atrial myxoma presenting with synchronous carotid and femoral embolism

Summary Synchronous embolism of the right femoral and the left internal carotid arteries, occurring in a 39-year-old teacher upon physical effort, was found to be due to a left atrial myxoma. Clinical findings, electrocardiogram and chest radiographs had suggested myocarditis. The patient died of cerebral infarction. In cases of suspected myocarditis, left atrial myxoma has to be considered in the differential diagnosis. Histological examination is recommended of any material obtained by embolectomy.

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Zusammenfassung Ausgehend von einem Myxom des linken Vorhofes, traten bei einem 39jährigen Lehrer unter körperlicher Belastung gleichzeitig embolische Verschlüsse der rechten Arteria femoralis und der linken Arteria carotis interna auf. Der Tumor wurde erst post mortem diagnostiziert. Der klinische Herzbefund ließ im vorliegenden Fall am ehesten an eine Myocarditis denken. In seltenen Fällen ist bei bestehendem Verdacht auf Myocarditis differentialdiagnostisch auch ein Vorhofmyxom in Betracht zu ziehen. Durch Embolektomie gewonnenes Material sollte immer histologisch untersucht werden.

     

Acute aortic occlusion as an unusual embolic complication of cardiac myxoma

Acute aortic occlusion is an infrequent but dangerous vascular emergency with a mortality rate of 50%, resulting from aortic saddle embolus, thrombosis of an atherosclerotic abdominal aorta, or sudden thrombosis of a small abdominal aortic aneurysm.     

外阴深部侵袭性血管黏液瘤临床病理观察

[目的]探讨外阴深部侵袭性血管黏液瘤的临床病理学特征.[方法]对2例外阴血管黏液瘤进行光镜观察和免疫组化检测.[结果]大体肿瘤为分叶状,组织学上肿瘤由梭形或星形细胞组成,胞浆少,核圆形或卵圆形,浅染,有中位小核仁,无核分裂相;肿瘤细胞密度低至中等,散在分布于黏液样或胶原纤维背景中,同时伴有不同管径的血管出现.免疫组化示肿瘤细胞阳性表达vimentin、desmin、PR,而actin、SMA、MSA、ER、S-100、CD34均阴性.[结论]外阴血管黏液瘤是一罕见、具有局部侵袭性的软组织肿瘤,WHO将其归为行为不确定的肿瘤,偶尔与血管肌纤维母细胞瘤等在形态上有重叠,通过仔细的组织学观察不难区分,此瘤通过手术局部扩大切除为佳,部分病例可局部复发.     

Massive right atrial myxoma presenting with syncope

A 65-year-old man presented to the emergency room following an episode of syncope. His vital signs and physical examination were unremarkable. A chest X-ray and an ECG were also normal. He was admitted to the hospital for further work-up. A computed tomography scan of his brain did not reveal any evidence of stroke, hemorrhage, or mass effect. A transesophageal echocardiogram, however, revealed tricuspid regurgitation and a right atrial mass with finger-like projections, which appeared to originate from the tricuspid valve. Left heart catheterization was performed, showing a 99% proximal right coronary artery stenosis. The patient was scheduled to undergo atrial mass resection, tricuspid valve annuloplasty, and coronary bypass. During the procedure, a large myxoma was found to be adherent to the right side of the atrial septum, adjacent to the fossa ovalis. The mass was friable and was attached to the endocardium by a pedicle. Following resection of the atrial mass and tricuspid valve annuloplasty, a single saphenous vein graft bypass to the right coronary artery was performed. The patient's postoperative course was unremarkable and he was discharged home on postoperative day 6.     

The Variations in the Immunologic Features and Interleukin-6 Levels for the Surgical Treatment of Cardiac Myxomas

Purpose In this study, we propose the existence of a relationship between cardiac myxomas and the immunologic features or interleukin-6 (IL-6), while also considering the optimal treatment of cardiac myxoma, especially “familial myxoma.” Methods In a 19-year period at our hospital, 20 patients underwent 21 operations for cardiac myxomas. The immunologic features and the IL-6 levels were measured pre-operatively in 13 cases and post-operatively in 10 cases. A case of “familial myxoma” was diagnosed based on molecular genetic analyses. Results No patients died in the hospital. The tumor size correlated with the preoperative IL-6 and/or α1-globulin values (P < 0.05). In addition, all of the immunologic features and IL-6 levels normalized by 4 weeks after surgery. “Familial myxoma” demonstrated recurrence without showing increases in either the immunologic features, inflammatory signs, or serum IL-6 levels. Conclusions Patients with cardiac myxoma should therefore be operated on immediately because the possibility that the tumor size might be large when IL-6 and/or α1-globulin values are high. In addition, cases of “familial myxoma” require careful observation and periodic echocardiography after surgery to identify any possible recurrence. Recently, molecular genetic analyses are therefore considered to be an important diagnostic tool for cardiac myxoma, especially “familial myxoma.” Our “familial myxoma” case demonstrated a C769T PRKAR1a mutation, which has also been observed in other cases of “familial myxoma.”     

Giant left atrial myxoma in an elderly patient: natural history over a 7-year period

We present the case of a 71-year-old woman with a 7-year history of a giant left atrial myxoma. The myxoma was attached to the atrial septum and occupied almost the entire left atrial cavity. The patient was hospitalized 4 times because of dyspnea on exertion, palpitations, fatigue, general asthenia, and weight loss. During prior hospitalizations, the patient had refused cardiac surgery. She developed several complications, including atrial fibrillation, mitral and tricuspid regurgitation, mesenteric embolism, pulmonary edema, and thrombotic stroke. We herein describe the natural history of left atrial myxoma in an elderly patient over a 7-year period.     

肌肉内粘液瘤的影像诊断

目的探讨肌肉内粘液瘤的X线、CT和MR表现,提高对本病的认识。方法回顾性分析我院近年来经手术及病理证实的2例肌肉内粘液瘤的影像表现特点。结果 2例患者,例1位于腹直肌,彩超显示腹壁低回声团,其内可见点棒状血流信号。例2位于长收肌,X线片表现为左股骨上段小粗隆下方一类圆形低密度区,边缘有硬化;CT表现为左大腿上段肌肉内囊性占位,增强扫描轻度强化,不均匀,周围骨质可见浅缺损;MR平扫呈稍长T1、混杂信号肿块,股骨上段内侧骨皮质局部不完整。结论罕见的肌肉内粘液瘤的CT、MR表现有一定的特点,综合分析其影像学表现,尤其是MR表现可提示诊断。