Case Discussion <Brief History> A 59-year-old woman was admitted due to progressively exertional dyspnea for two months. The patient had been well until six months before admission, when she had mild dyspnea on exertion and got fatigue easily. There was no chest pain but mild palpitation during dyspnea attack. The dyspnea relieved after a short period of rest. In recent two months, the exertional dyspnea progressed and her exertional capacity was significantly limited. There was no fever, weight loss, dizziness, or airway symptoms in recent 6 months. Tracing back her past medical history, there were no cardiac or pulmonary disease were diagnosed. On physical examination, her blood pressure was 132/68 mmHg and her respiratory rate was 22/min. Neither lymph node enlargement nor jugular vein enlargement was noted on the neck. Her breathing sound was clear. In cardiac auscultation, the rhythm was irregularly irregular with loud and widely split S1; an early diastolic sound was identified. A grade III/VI holosystolic murmur and Gr II/VI diastolic murmur were noted over apex. The abdomen was soft and bowel sound was normoactive. The extremities were freely movable without significant edema or cyanosis. In electrocardiogram, atrial fibrillation with a ventricular rate of 76 per minute was identified. Neither q wave nor significant ST-T change was noted. Chest roentgenogram revealed borderline heart size without pulmonary lesions. The laboratory data were shown in table 1. A transthoracic echocardiography was performed to evaluate her heart function. A 4.5*2.15 cm oscillating mass attaching on interatrial septum (IAS) was identified in left atrium (LA). (Figure 1) In magnate resonance image, the LA mass was isointese in T1 and mild hyperintence in T2. A diagnosis of myxoma was made according to her clinical course, physical finding and image studies. Coronary angiography showed patent coronary artery and identified right coronary artery as the tumor supplying vessel. (Figure 2) Furthermore, the tumor was noted as a filling defect in levophase of pulmonary angiogram. (Figure 3 ) The patient received tumor excision on the next day smoothly. The pathology proved the clinical diagnosis of myxoma. She was discharged smoothly two weeks after operation, and remained asymptomatic in 6-month follow-up. <Discussion> Primary tumors of the heart are rare. Three quarters of the tumors are benign, and half the benign heart tumors are myxomas. The mean age of patients with sporatic myxomas is 56 years, and 70 percent of them were female. About 86% of myxoma occur in LA and more than 90% are solitary. Myxoma can also occur in the right atrium and, less often, in the right and left ventricle (3-4% each). The usual site of attachment of LA myxoma is in the area of fossa ovalis (90%). The other attaching site included anterior, posterior wall, and appendage (10%); mitral and tricuspid valves, although rarely, had been reported. The clinical features of myxomas are determined by their location, size, and mobility. Most patients present with one or more of the triad of embolism (occur in 30-40% of myxoma patients), intracardiac obstruction, and constitutional symptoms. Occasionally, there are no symptoms, particularly with small tumors. The symptoms and sign of intracardiac obstruction mimic the clinical picture of mitral or tricuspid valve stenosis. The extent of valvular obstruction may vary with body position. If the tumor is large enough, temporary complete obstruction of the orifice of the mitral or tricuspid valve may occur, resulting in syncope or sudden death. Constitutional disturbances included fatigue, fever, erythematous rash, arthralgia, myalgia, and weight loss. The laboratory abnormalities included anemia (sometimes polycythemia), and elevations in the erythrocyte sedimentation rate and the serum C-reactive protein, globulin, and serum interleukin-6 levels. The diagnosis depends on image studies. Transthoracic echocardiography can generally be used to determine the location, size, shape, attachment, and mobility of a myxoma. Transesophageal echocardiography (TEE) provides unimpeded visualization of the atria, atrial septum, and is therefore particularly helpful in detecting the site of insertion. Other image studies, like computed tomography or magnate resonance image, can differentiate tissue composition. It makes possible to identify solid, liquid, hemorrhagic, and fatty, space-occupying tumors. The treatment of choice for myxomas is surgical removal and it is usually curative. After the diagnosis has been established, surgery should be performed promptly because of the possibility of embolic complications or sudden death. The short- and long-term prognosis is excellent; the rate of operative mortality was 0 to 3 percent. Recurrence of sporatic myxomas is only 1 to 3 percent for sporadic tumors. Incomplete resection is thought to be the reason for a recurrence. Table 1. Laboratory data [ CBC+PLT ] WBC  RBC  HB HCT MCV MCH  MCHC PLT K/μL  M/μL g/dL %  fL  pg g/Dl K/μL   5.42 4.43 13.5 40.7 91.9 30.5 33.2 332.0 Seg Eos Baso Mono Lym % % % % % 69.2 0.3 0.2 5.3 25.0 [ Biochemistry ] ALB GLO  BUN CRE T-BIL AST GLU mg/dl mg/dl mg/dl mg/dl mg/dl U/l  mg/dl 4.6 3.8 10.5 1.1 0.8 23.0 103.0 Na K Cl Ca Mg Mmmole/l mmole/l mmole/l mmole/l mmole/l 145.0 4.7 110.0 1.97 0.8 [ Serology ] C-reactive protein: 2.7 mg/dl Figure legends Figure 1. Five chamber view of transthoracic echocardiography. A 4.5*2.15 mass was noted in left atrium. Figure 2. Coronary angiogram (right coronary artery). A feeding artery (black arrow) was branched from right coronary artery and supplied the myxoma (white arrow). Figure 3. Pulmonary angiogram. In the levophase of pulmonary angiogram, a mobile filling defect (white arrow) was noted in left atrium. 繼續教育考題 1. (A) Which chamber does myxoma usually occur? A left atrium B right atrium C left ventricle D right ventricle 2. (D) Which symptom is least likely in a patient with myxoma?  A exertional dyspnea B fever C weight loss D headache 3. (C) In cardiac auscultation, which is least likely in myxoma patients? A diastolic sound B wide split S1 C wide split D systolic murmur 4. (C) Which is not the complication of myxoma?  A distal embolism B sudden death C cardiac temponade D acute lung edema 5. (A) Which syndrome is not associated with myxoma? A Turner syndrome B Carney's syndrome C NAME syndrome D LAMB syndrome. 6. (C) In the following examination, what is the most useful in detecting myxoma? A electrocardiography B chest roentgenogram C echocardiography D thalium-201 perfusion scan 7. (C) Which of the following attachment site of left atrial myxoma is least likely? A fossa ovalis B left atrial appendage C mitral annulus D left atrial posterior wall 8. (C) Which is not true in sporadic myxoma?  A female predominant B atrium predominant C easily recurrent D multiple myxoma is rare 9. (A) When should patients with myxoma receive operation? A as soon as possible B when patients has symptoms C when pulmonary wedge pressure exceed 25mmHg D when left ventricle end-diastolic diameter excess 55mm 10. (C) Which of the following cardiac tumor had lowest incidence? A fibroma B myxoma C lymphagioma D rhabdomyomas. 答案解說 (A ) About 86% of myxomas occur in LA. (D ) Most patients present with one or more of the triad of embolism (occur in 30-40% of myxoma patients), intracardiac obstruction, and constitutional symptoms. The symptoms and sign of intracardiac obstruction mimic the clinical picture of mitral or tricuspid valve stenosis (ex:acute lung edema, exertional dyspnea, paroxysmal nocturnal dyspnea, leg edema). Constitutional disturbances included fatigue, fever, erythematous rash, arthralgia, myalgia, and weight loss. (C ) The auscultatory findings are characteristically variable and depend on body position in cases of mobile tumors. Either systolic or diastolic murmurs may be heard. Diastolic murmurs are due to obstructed filling of the left or right ventricle; systolic murmurs occur if the myxoma interferes with the closure of the atrioventricular valves or narrows the outflow tract. In patients with left atrial myxomas, the first heart sound is often loud and widely split, because the tumor has caused a delay in the closure of the mitral valve. In about one third of the patients, protodiastolic murmurs can be heard 80 to 150 ms after the second heart sound (called "tumor plop"). (C  )  The clinical features of myxomas are determined by their location, size, and mobility. In 30-40% of myxoma patients, embolism occurs. The symptoms and sign of intracardiac obstruction mimic the clinical picture of mitral or tricuspid valve stenosis (ex:acute lung edema, exertional dyspnea, paroxysmal nocturnal dyspnea, leg edema). If the tumor is large enough, temporary complete obstruction of the orifice of the mitral or tricuspid valve may occur, resulting in syncope or sudden death.  (A )  Familial cardiac myxomas constitute approximately 10 % of all myxomas. Some patients with cardiac myxoma have a syndrome, frequently called "syndrome myxoma"or"Carney's syndrome", that also consist of (1) myxoma in other location (breast or skin), (2) spotty pigmentation (3) endocrine overactivity. Although the cause of the syndrome myxoma is unknown, it has been proposed to result from a widespread abnormality resulting in excessive proliferation of certain mesenchymal cells, and excessive glycosaminoglycans production by them. Patients may have two or more components of this complex. Some patients have been said to have the NAME syndrome (nevi, atrial myxoma, myxoid neurofibroma, ephelides) or LAMB syndrome (lentigines, atrial myxoma, and blue nevi). (C) The diagnosis depends on image studies. The most common tools includes transthoracic echocardiography, TEE, computed tomography and magnate resonance image, can differentiate tissue composition.  (C)  The usual site of attachment of LA myxoma is in the area of fossa ovalis (90%). The other attaching site included anterior, posterior wall, and appendage (10%); mitral and tricuspid valves, although rarely, had been reported. (C) Sporadic cardiac myxomas constitute approximately 90 % of all myxomas. Most sporadic myxomas occur in LA and more than 90% are solitary. Recurrence of sporatic myxomas is only 1 to 3 percent. (A) The treatment of choice for myxomas is surgical removal and it is usually curative. After the diagnosis has been established, surgery should be performed promptly because of the possibility of embolic complications or sudden death.  (C)  Primary tumors of heart are rare. Three quarters of the tumors are benign and nearly half the benign heart tumors are myxomas. The majority of the rest are lipomas, papillary fibroelastomas, and rhabdomyomas. Fibromas, hemangiomas, teratomas, and mesotheliomas of the atrioventricular node are found less frequently; granular-cell tumors, neurofibromas, and lymphangiomas are very rare.