Malignant myxoma of left atrium

Introduction of left atrial malignant myxoma The naming of this disease is not uniform, because only case reports, some scholars attributed to malignant transformation of cardiac myxoma, some scholars call it cardiac malignant myxoma. basic knowledge The proportion of illness: 0.005% Susceptible people: no specific population Mode of infection: non-infectious Complications: heart failure, arterial embolism, arrhythmia

Causes of left atrial malignant myxoma

(1) Causes of the disease

Cardiac myxoma is a benign tumor of the heart. It originates from the atrium of the atrium and grows like a polyp. The pedicle at the bottom is connected to the endocardium, which causes the tumor to protrude into the heart chamber and has a certain degree of activity with changes in body position and blood flow. The tumor is easily ruptured, causing peripheral arterial embolism and organ infarction after detachment. Although the atrial myxoma is benign, the resection is not complete, the local recurrence can destroy the vascular wall, and a few patients have a family genetic predisposition, which belongs to autosomal dominant inheritance. These patients often have endocrine system tumors. At this time, they are called myxomas syndrome. Very few patients can develop malignant lesions and become mucinous sarcomas.

(two) pathogenesis

Visual inspection can be divided into 3 types:

1. Bulk type: The tumor is a solid mass, and the tumor has a complete capsule or the tumor fragments can be detached to cause embolism.

2. Polyp type: The tumor is a polypoid-like grape cluster, which is outsourced to the endothelial cell layer. The tumor is brittle and can cause embolism after shedding.

3. Mixed type: The above type 2 is mixed, the tumor grows rapidly, adjacent tissues are often infiltrated, and the surface of the tumor is covered with endothelial cells under microscope examination. The tumor is mainly composed of polysaccharide and mucin-like matrix, with plasma cells, lymphocytes and Polygonal cells, and fibroblasts and phagocytic cells are scattered in the loose connective tissue. There are microvascular extension and hemochromatosis in the tumor. At the same time, the tumor cells are abundant, the cell morphology is different, the nucleus is large and the staining is deep. With mitotic figures, tumor cells can invade small blood vessels to form tumor thrombi.

Left atrial malignant myxoma prevention

1. Left atrial malignant myxoma should be operated as soon as possible after diagnosis. Some people even think that the emergency operation is to prevent the tumor from clogging the valve mouth, distant metastasis or tumor shedding and embolism and death.

2. Non-specific symptoms such as fever, rapid erythrocyte sedimentation rate, lung snoring, etc., medical treatment is still unable to control, not a surgical contraindication, such as co-infection, heart failure can not afford surgery should also be actively treated, to create surgical conditions.

Left atrial malignant myxoma complications Complications, heart failure, arterial embolism, arrhythmia

The disease often combined with transient ischemic attack, heart failure, arterial embolism, arrhythmia; late complications of multiple organ failure.

Left atrial malignant myxoma symptoms Common symptoms Liver and spleen air short chest pain fatigue halo ESR increased fast dizziness hemoptysis jugular vein filling

The clinical manifestations of left atrial malignant myxoma are not characteristic and can be classified into three categories.

1. Systemic symptoms: due to hemorrhage, degeneration, necrosis of left atrial malignant myxoma, can cause fever, anemia, fatigue, joint pain, urticaria, poor appetite, weight loss, and even cachexia, enlargement of the left atrium, compression of the esophagus, Obstructed by eating, there is still increased erythrocyte sedimentation rate, abnormal serum protein electrophoresis (low albumin, increased globulin) and C-positive, anti-myocardial antibody titer increased when symptoms appear, tumor titer decreased after tumor resection, clinical course progress deteriorated rapidly .

2. Embolism: The left atrial malignant myxoma is loose and fragile, and its fragments or emboli on the surface of the tumor are the most common cause of embolism. The left atrial embolus enters the systemic circulation, causing embolism of the brain, limbs and viscera. The size of the embolus is different, so the infarct size is very different, and the severity of the symptoms is also very different. The lighter only has transient syncope. In severe cases, coma, paralysis, limb necrosis and even death may occur. Peripheral embolization histological examination has malignant tumor cells. .

3. Cardiac manifestations: Left atrial malignant myxoma grows rapidly. Due to the size of the tumor and the different degrees of activity, it can cause different degrees of mechanical obstruction of blood flow and affect the function of atrioventricular valve. The left atrial diastolic tumor obstructs the mitral valve orifice. There is a rumbling murmur that resembles mitral stenosis. When the mitral valve prolapse is predominant, the murmur can only be heard during the systolic phase, but this is not much, and most of them are double-phase murmurs. In a small number of cases, diastolic early and mid-term tumor fluttering sounds can be heard. Due to the obstruction of the tumor, the left atrial pressure is increased, followed by pulmonary congestion. S4 and S1 are enhanced and split, and the murmur often changes with the change of body position. Long-term left atrial pressure rise, accompanied by increased pulmonary pressure and right heart failure, patients with jugular vein filling, anger, lower extremity edema, hepatosplenomegaly, and even ascites sign, patients often have active palpitation, shortness of breath , dizziness and hemoptysis and other symptoms, common chest pain, can be quite serious and bloody pericardial effusion, domestic literature reported that left atrial malignant myxoma local infiltration, through the bloodstream or lymphatic tissue to distant transfer, It causes the growth and growth of lung, kidney and liver tumors, and finally merges with multiple organ failure and dies.

Examination of left atrial malignant myxoma

1. ESR increases, serum protein electrophoresis is abnormal (albumin is reduced, globulin is increased) and C is positive.

2. Anti-myocardial antibody titer increased.

3. Electrocardiogram: no characteristic manifestations, can be normal ECG or left atrial right ventricular hypertrophy and myocardial damage, but also arrhythmia and ST-T segment changes.

4. X-ray examination: There are different degrees of pulmonary congestion in the two lung fields, and the heart is mild to moderately enlarged, which is similar to the performance of mitral valve disease.

5. Heart sound map: In some patients, the intensity of the noise can vary with different body positions.

6. Echocardiography: It has special diagnostic value for left atrial malignant myxoma, but the nature of the tumor cannot be determined.

(1) M-mode echocardiography: can indicate the presence of tumor but can not determine the size and location of the tumor, especially with mitral stenosis.

(2) Two-dimensional echocardiography: The whole picture (size) of the tumor can be observed, and the cut surface can also be observed to understand the attachment position and activity of the tumor, mainly as the left atrium cavity is enlarged; dense cloud appears in the heart cavity. Abnormal echo of the ray-like mass; the abnormal echo changes with the opening and closing of the atrioventricular valve. In the diastolic phase, the abnormal echo can protrude into the atrioventricular valve or the tumor part protrudes into the left ventricle, and the tumor in the systolic phase is reintroduced into the left atrium cavity. Internal and late esophageal echocardiography have a greater diagnostic value for left atrial malignant myxoma, and therefore there is a tendency to replace preoperative cardiac catheterization or angiography.

7. Magnetic Resonance Imaging (MRI) Irregular edge of the tumor and/or muscle wall infiltration can obtain the same data as echocardiography, and can achieve accurate anatomical positioning.

Diagnosis and diagnosis of left atrial malignant myxoma

Diagnostic criteria

According to clinical symptoms, signs combined with two-dimensional echocardiography (IDE), esophageal echocardiography, magnetic resonance and histopathology, the diagnosis can be established, the possibility of left atrial malignant myxoma should be considered in the following cases:

1. Sudden or repeated arterial embolism can be explained without other reasons, especially in patients with sinus arrhythmia.

2. Unexplained episodes of palpitation, shortness of breath, hemoptysis or syncope, especially postural changes induce aggravation or alleviation.

3. Unexplained apex or bottom-bottom murmur, without a clear history of rheumatism, if the murmur changes with the body position changes more meaningful.

4. Long-term fever, increased erythrocyte sedimentation rate, similar to infective endocarditis, and culture negative or treatment is ineffective.

5. Medical treatment is difficult to work, and rapidly deteriorated intractable heart failure.

Differential diagnosis

Left atrial malignant myxoma is often distinguished from rheumatic mitral stenosis, atrial thrombus and infective endocarditis.

1. Identification of mitral stenosis with rheumatic heart disease: Left atrial malignant myxoma has no history of rheumatic fever, symptoms and signs often suddenly appear or disappear, develop rapidly, symptoms and murmurs change with body position, most do not open the sound, but It can be heard and diastolic "tumor fluttering" and can be heard on the chest and back.

2. With left atrial thrombus and infective endocarditis: There are many symptoms and signs similar to left atrial malignant myxoma, but IDE and esophageal echocardiography can be used as an identification.

In addition, it needs to be differentiated from tricuspid valve disease, cardiomyopathy, Ebstein malformation, and lung disease.

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