Michael Samara and Brian P. Griffin
Primary cardiac tumors are rare occurring with a prevalence ranging from 0.001% to 0.03% in unselected autopsy series. Metastatic involvement of the heart is significantly more common, present at autopsy in roughly 20% of patients dying from extracardiac malignancies. The vast majority of primary cardiac tumors are of mesenchymal origin and accordingly display a variety of histopathologies. Over 75% of primary tumors are benign. Symptoms when present may be related to obstruction, interference with valvular structures resulting in regurgitation, direct invasion of the myocardium with associated impaired contractility, arrhythmia and conduction disorders, pericardial effusion, or embolization.1,2
BENIGN TUMORS (TABLE 59.1)
TABLE
59.1 Benign Primary Cardiac Tumors
Myxomas
Myxomas represent the most common primary cardiac tumors in adults, accounting for approximately 25% of all cardiac neoplasms and 75% of all benign primary cardiac tumors. While once thought to represent organized thrombus, gene expression and immunohistochemical studies have firmly concluded that they are neoplasms arising from multipotent mesenchymal cells.3 Myxomas have a bimodal peak onset in the third and sixth decades of life with 65% occurring in women. Seven to ten percent of myxomas are familial in origin.4 The autosomal dominant Carney complex represents the majority of these familial cases and is characterized by cardiac and extracardiac myxomas (breast and skin), lentigines, hyperendocrine states, and nonmyxomatous extracardiac tumors including testicular Sertoli cell tumors, schwannomas, pituitary adenomas, and thyroid tumors. Other familial syndromes associated with myxoma formation include the LAMB (lentigines, atrial myxoma, mucocutaneous myxoma, and blue nevi) and NAME (nevi, atrial myxoma, myxoid neurofibromata, and ephelides) syndromes. In contrast to sporadic cases, familial myxomas have no clear predilection for sex or age, are multicentric, apically located, and more likely to recur following resection (20% of cases in the Carney complex).5
Over 90% of myxomas are solitary with 80% located in the left atrium, most commonly attaching to the interatrial septum at the inferior border of the fossa ovalis. They may however arise from any endocardial surface within the heart with 15% occurring in the right atrium and the remaining 5% arising from the ventricles or atrioventricular (AV) valves.6 Myxomas are pedunculated with surfaces that may be smooth or villous. On gross examination they have a gelatinous consistency with foci of hemorrhage, calcification, ossification, and frequently cystic components. Size at the time of diagnosis is typically 4 to 8 cm in diameter though myxomas as large as 16 cm have been described in the literature.
As with all cardiac tumors, symptoms are highly variable and depend largely on tumor size, location, and mobility. The classic triad of symptoms includes obstructive symptoms (syncope, sudden cardiac death, or symptomatic heart failure [HF]), embolic phenomenon, and constitutional symptoms (fever, weight loss, arthralgias, and Raynaud syndrome) thought secondary to release of IL-6. Findings on auscultation include diastolic and systolic murmurs. The characteristic low-pitched “tumor plop ” occurring 80 to 120 ms after S2 (i.e., after an opening snap and prior to a third heart sound) and correlating with tumor movement through the mitral valve and contact with the ventricular wall is heard in only a minority of cases.4
Laboratory abnormalities include elevated erythrocyte sedimentation rates and C-reactive protein, anemia (often hemolytic), polycythemia, and thrombocytopenia. The diagnosis is made by echocardiography, contrast-enhanced computed tomography (CT), or cine gradient-echo cardiac MR (CMR) where myxomas appear as heterogeneous density spherical or ovoid masses (Fig. 59.1). Thrombus is the primary differential diagnosis with protrusion through the mitral annulus being the most specific finding favoring the diagnosis of myxoma.
FIGURE 59.1 A: Left atrial myxoma. B: Surgical specimen, left atrial myxoma (same as part A). C: Right atrial myxoma.
Treatment consists of surgical resection, which is associated with a low operative mortality, and, with the exception of familial cases, a low recurrence rate (0% to 3%). Complete resection of the tumor and avoidance of excessive manipulation is essential to preventing local and distant recurrences, respectively. As with all cardiac tumors, this is best achieved with extracorporeal circulatory support via femoral or azygous vein cannulation in order to avoid tumor fragment embolization, facilitate direct visualization, and rule out metasynchronous tumors. As with all resected cardiac tumors, annual noninvasive imaging is recommended for follow-up.6
Papillary Fibroelastoma
Papillary fibroelastoma is the second most common benign primary cardiac tumor and the most common to involve the cardiac valves. Eighty percent of fibroelastomas occur in the left cardiac chambers with the aortic and mitral valves being the most common sites. Fibroelastomas are typically found on the downstream aspect of the valve and appear as frondlike projections of collagen and elastic fibers emanating from a short central stalk (often described as sea anemone like) (Fig. 59.2). Their small size and highly mobile nature make them best suited to visualization with echocardiography. They can be differentiated from Lambl excrescences by their location on noncontact surfaces of the valve. Symptoms when present are due to systemic embolization with stroke and myocardial infarction being the most feared complications. The current therapeutic approach is surgical excision for fibroelastomas that are highly mobile, > 1 cm in size or associated with prior embolization. In nonsurgical candidates with prior embolic events long-term anticoagulation may be considered.7
FIGURE 59.2 A, B: Aortic valve papillary fibroelastoma.
Other Benign Primary Cardiac Tumors
Lipoma
Cardiac lipomas are the third most common benign primary cardiac tumors and as their name implies represent well-encapsulated collections of mature adipocytes. Subepicardial and subendocardial locations predominate though intramyocardial locations can also occur. Clinical presentations are largely dictated by location with subepicardial lipomas rarely resulting in symptoms unless very large and associated with pericardial effusion or chamber compression. Subendocardial lesions may result in hemodynamic obstruction when large and intramyocardial lipomas may occasionally present with conduction disorders or arrhythmia. Because lipomas have a nonspecific echocardiographic appearance, CT has become a favored diagnostic modality demonstrating a well-circumscribed mass with low attenuation similar to subcutaneous fat. Surgical resection is reserved for symptomatic cases.8
Lipomatous hypertrophy of the interatrial septum (LHAS) is a nonneoplastic excessive accumulation of nonencapsulated fat > 2 cm in diameter in the superior and inferior portions of the atrial septum, sparing the fossa ovalis. LHAS is more common in elderly, obese, and male patients. Rhythm disturbances and hemodynamic obstruction necessitating surgical intervention are rare.
Rhabdomyoma
Cardiac rhabdomyomas are quite rare in adult populations but represent the most common benign primary cardiac tumors in the pediatric population with more than 80% occurring in patients < 1 year of age. They are thought to represent hamartomatous growths as opposed to true neoplasms with an absence of mitotic activity and a tendency to spontaneously regress. The later characteristic has led to the recommendation that asymptomatic lesions be followed conservatively.4 There is a clear association with tuberous sclerosis with 80% of rhabdomyoma patients having the disease. In these cases multiple tumors are the rule.9
Fibroma
Cardiac fibromas are the second most common benign primary cardiac tumor in pediatric populations and again are rarely seen in adults. They are typically located in the left ventricular (LV) free wall, ventricular septum, or apex with the LV involved five to ten times more frequently than the RV. They can grow to large sizes with clinical presentations including signs and symptoms of mechanical obstruction, congestive HF due to systolic or diastolic dysfunction, or malignant arrhythmias. While nonspecific, the diagnosis is often suggested by the presence of calcification (Fig. 59.3). Definitive treatment involves resection as unlike rhabdomyomas they rarely regress. Cardiac fibromas may occur as part of the Gorlin syndrome (cardiac fibromas, multiple basal cell carcinomas, jaw cysts, and skeletal abnormalities).4
FIGURE 59.3 A: Left ventricular fibroma (B) MRI, left ventricular fibroma.
Hemangioma
Cardiac hemangiomas are vascular malformations composed of endothelial-lined channels with interspersed fat and fibrous septa. They represent < 2% of benign primary cardiac tumors and can occur at any age, in any chamber, and at any level from pericardium to endocardium. They appear hyperechoic by echocardiography and have characteristic intense contrast enhancement on CT. Similarly coronary angiography may demonstrate findings consistent with perfusion although in both cases contrast enhancement may vary with “low flow ” cavernous hemangiomas having relatively reduced perfusion. Given that they often regress spontaneously, conservative management is favored in asymptomatic patients.
MALIGNANT TUMORS (TABLE 59.2)
TABLE
59.2 Malignant Primary Cardiac Tumors
Malignant cardiac tumors account for approximately 25% of primary cardiac tumors. Morphologic features suggesting malignancy include right-sided location (with the exception of leiomyosarcoma), broad-based attachment, involvement of multiple chambers, size > 5 cm, associated pericardial effusion, and extension into the mediastinum, great vessels, or pulmonary veins. As metastatic disease involving the heart is significantly more common, detailed clinical examination and appropriate imaging are warranted to rule out the possibility of a distant noncardiac primary.9,10
Transesophageal echocardiography (TEE) is the initial diagnostic test of choice; however, owing to its inability to demonstrate infiltration, regional invasion, and distant metastases, it is important to supplement with CT and CMR. Currently, no TNM classification exists, and treatment strategies remain poorly defined with surgery recommended when complete resection is feasible or when severe symptoms require palliation.10
The vast majority of primary malignant cardiac tumors are rapidly proliferating sarcomas. They typically result in death secondary to wide spread infiltration, obstructive symptoms, or diffuse metastases with a median survival of 6 to 12 months. Survival is improved significantly in cases where complete surgical resection is possible. In well-selected patients, cardiac transplantation or autotransplantation has been successfully employed. A team approach to care is required as adjuvant/neoadjuvant chemotherapy and external beam radiation therapy are often used in conjunction with surgery (Fig. 59.4).
FIGURE 59.4 Left atrial sarcoma.
Primary cardiac lymphomas represent the second most common class of primary malignant cardiac tumors with a frequency that has increased in the era of solid organ transplantation. The disease is more common in immunocompromised hosts such as those with HIV associated lymphoma or post transplant lymphoproliferative disorder (PTLD) where extracardiac involvement is the rule at the time of diagnosis. Treatment typically consists of systemic chemotherapy.10
SECONDARY CARDIAC TUMORS
Tumor metastases to the heart are 20 to 40 times more common than primary malignant tumors. Primary tumors that metastasize to the heart in order of descending frequency include lung, breast, lymphoma/leukemia, esophageal, uterine, melanoma, gastric, sarcoma, and colon. Melanoma has the greatest propensity to metastasize to the heart (60% to 70% cardiac involvement with metastatic disease). Metastases reach the heart via hematologic or lymphatic spread (melanoma, lymphoma, and breast), invasion through venous structures (renal, hepatocellular, adrenal, uterine), or direct invasion (lung, breast, esophageal) (Fig. 59.5). The pericardium is the most common site of involvement, followed by myocardial involvement, and rarely endocardial and valvular surfaces (Fig. 59.6).11
FIGURE 59.5 A, B: Inferior vena cava/right atrial tumor, renal cell carcinoma.
FIGURE 59.6 MRI, pericardial metastasis.
Since nearly all patients with cardiac metastases have widespread disease, therapy is generally directed at the primary tumor. Removal of a malignant pericardial effusion by pericardiocentesis or pericardial window with or without pericardial sclerosis may palliate symptoms and delay or prevent recurrence.
Renal Cell Carcinoma
Renal cell carcinoma is unique in its propensity to invade the vena cava with locally advanced disease being classified in part on the basis of tumor thrombus extension below (Stage IIIb) and above (Stage IIIc) the diaphragm. For the approximately 5% of patients with inferior vena cava (IVC) involvement, radical nephrectomy with tumor thrombus resection is the preferred treatment strategy. In most cases this can be achieved without cardiopulmonary bypass. Hypernephromas and leiomyomatous sarcomas (uterine) may also invade the heart via the IVC.12
CARCINOID HEART DISEASE
Carcinoid tumors are rare gastrointestinal neuroendocrine tumors typically arising from the enterochromaffin cells of the gastrointestinal tract. While metastases to the heart are exceedingly rare, carcinoid heart disease resulting from deposition of fibrous tissue occurs in approximately 50% of patients with the disease and represents a major source of morbidity and mortality. Interestingly 20% of carcinoid patients present with cardiac manifestations in contrast to the classic vasomotor symptoms (flushing) and gastrointestinal hypermotility that may only be present in a small minority of patients with carcinoid tumors.
Carcinoid heart disease is characterized by the plaquelike deposition of fibrous tissue on the valvular endocardium and more rarely on the intima of the pulmonary arteries and aorta. These deposits appear to be mediated by high circulating concentrations of serotonin and typically require hepatic metastases or a primary ovarian carcinoid (via direct venous drainage into the IVC) to bypass inactivation in the liver. The right-sided valves are preferentially affected due to further inactivation of humoral mediators in the lung, though in the setting of overwhelming elevations in circulating serotonin levels, intracardiac shunting (patent foramen ovale/atrial septal defect [PFO/ASD]), or bronchial carcinoids, left-sided lesions have been described.
The diagnosis of carcinoid syndrome is best made using the 24-hour urine excretion of 5-hydroxyindoleacetic acid (HIAA) the terminal product of serotonin metabolism. The characteristic echocardiographic features include thickening and retraction of immobile tricuspid valve leaflets with associated tricuspid regurgitation. Tricuspid stenosis is less common.
Involvement of the pulmonic valve is typical with coexistent pulmonary regurgitation or stenosis. The causative plaques are composed of accumulations of smooth muscle cells and mucopolysaccharides and are histopathologically and echocardiographically identical to those observed in the setting of chronic ingestion of ergotamines or fenfluramine-phentermine.
Management of localized tumors typically involves surgical resection. Patients experiencing carcinoid syndrome typically have disseminated metastatic disease necessitating treatment with chemotherapy. The somatostatin analog octreotide can be used in cases with prominent flushing or diarrhea. Patients with carcinoid heart disease may remain asymptomatic for extended periods of time but ultimately present with symptoms of severe tricuspid regurgitation and right-sided HF. While surgical mortality is high, patients treated with valve replacement have superior survival to their medically treated counterparts.13
ACKNOWLEDGMENT
The authors wish to acknowledge Sreenivas Kamath, MD for his contributions to the first edition of this chapter.
REFERENCES
1. Burke A, Virmani R. Tumors of the heart and great vessels. In: Atlas of Tumor Pathology. 3rd Series. Fasicle 16. Washington, DC: Armed Forces Institute of Pathology; 1996.
2. McAllister HA Jr, Fenoglio JJ Jr. Tumors of the cardiovascular system. In: Atlas of Tumor Pathology. 2nd Series. Fasicle 15. Washington, DC: Armed Forces Institute of Pathology; 1978.
3. Lie JT. The identity and histogenesis of cardiac myxomas: a controversy put to rest. Arch Pathol Lab Med. 1989;113:724–726.
4. McManus B, Lee C. Primary tumors of the heart. In: Braunwald E, Zipes DP, Libby P, eds. Heart Disease. 8th ed. Philadelphia: WB Saunders; 2007.
5. Carney JA, Gordon H, Carpenter PC, et al. The complex of myxomas, spotty pigmentation and endocrine overactivity. Medicine. 1985;64:270–283.
6. Percell RL, Henning RJ, Patel MS. Atrial myxoma: case report and a review of the literature. Heart Dis. 2003;5:224–230.
7. Sun JP, Asher CR, Yang XS, et al. Clinical and echocardiography characteristics of papillary fibroelastoma: a retrospective and prospective study in 162 patients. Circulation. 2001;103(22):2687–2693.
8. Hoey ET, Mankad K, Puppala S, et al. MRI and CT appearances of cardiac tumours in adults. Clin Radiol. 2009;64: 1214–1230.
9. Grasso AW Barman N. Cardiac tumors. In: Griffin BP, Topol EJ, eds. Manual of Cardiovascular Medicine. 3rd ed. Philadelphia: Lippincott Williams & Wilkins; 2009:288–293.
10. Simpson L, Kumar SK, Okuno SH, et al. Malignant primary cardiac tumors: review of a single institution experience. Cancer. 2008;112(11):2440–2446.
11. Silvestri F, Bussani R, Pavletic N, et al. Metastases of the heart and pericardium. G Ital Cardiol. 1997;27(12):1252–1255.
12. Boorjian SA, Sengupta S, Blute ML. Renal cell carcinoma: vena caval involvement. BJU Int. 2007;99(5):1239–1244.
13. Bernheim AM, Connolly HM, Hobday TJ, et al. Carcinoid heart disease. Prog Cardiovasc Dis. 2007;49(6):439–451.
QUESTIONS AND ANSWERS
Questions
1. True statements regarding cardiac myxomas include all of the following except:
a. They can arise anywhere within the heart.
b. They are the most common primary cardiac tumor.
c. Approximately 80% occur in the left atrium.
d. The majority are familial.
e. They may be associated with syncope, fever, or stroke.
2. True statements regarding papillary fibroelastomas include all of the following except:
a. They have a fronded appearance.
b. They have a benign histology.
c. The vast majority arise on the right side.
d. They have significant embolic potential.
e. They are the most common tumor involving the cardiac valves.
3. Which of the following is not part of the Carney complex?
a. Lentigines
b. Extracardiac myxomas
c. Testicular Sertoli cell tumors
d. Schwannomas
e. Hypoadrenalism
4. Which of the following malignancies has the highest propensity for cardiac metastasis?
a. Lung cancer
b. Renal cell carcinoma
c. Melanoma
d. Breast cancer
e. Colon cancer
5. Leiomyosarcomas can be differentiated from myxomas on the basis of which of the following echocardiographic features?
a. Propensity for right-sided heart chambers
b. Broad based attachment
c. Extension into the pulmonary vein
d. Attachment to the interatrial septum
e. b and c
6. A 32-year-old asymptomatic man with tuberous sclerosis is incidentally found to have a 1 × 1.5 cm intramyocardial mass in the left ventricular (LV) free wall on a transthoracic echocardiogram performed during an executive physical. How should you proceed with his diagnosis/management?
a. Surgical consultation for resection
b. Transesophageal echocardiogram to better characterize lesion
c. Positron Emission Tomography with F-18 fluorodeoxyglucose to assess for metabolic activity
d. Conservative management and reassurance
e. Computerized tomography (CT) scan to better characterize lesion
7. A 59-year-old female with a history of liver transplantation for cryptogenic cirrhosis presents with a 3-month history of progressive dyspnea on exertion and lower extremity edema. On history, she also endorses fever, night sweats, and a 10 pound unintentional weight loss. Transthoracic echocardiography demonstrates a 3 × 4 cm mass occupying the right atrium and a moderate pericardial effusion without tamponade physiology. An extensive evaluation for extracardiac tumors is unrevealing. What is the most likely diagnosis?
a. Angiosarcoma
b. Primary cardiac lymphoma
c. Mesothelioma
d. Rhabdomyosarcoma
e. Myxoma
8. A 43-year-old man with a history of multiple basal cell carcinomas is admitted to your service with progressive heart failure (HF) symptoms and syncope. The evening following admission he is noted to have multiple episodes of nonsustained monomorphic ventricular tachycardia. His transthoracic echo demonstrates 4 × 6 cm intramyocardial tumor in the LV myocardium with extensive calcification. What is the preferred treatment?
a. Initiation of amiodarone and continued telemetry monitoring
b. Referral to electrophysiology for implantation of an implantable cardioverter defibrillator
c. Initiation of HF pharmacotherapy including beta antagonist therapy once euvolemic
d. Referral for surgical resection
9. A 43-year-old female with biopsy proven carcinoid tumor with liver metastases presents to your clinic requesting a second opinion on the management of her valvular heart disease. She reports a 3-month history of progressive lower extremity edema and dyspnea on exertion. She denies flushing or diarrhea. On examination she has holosystolic murmurs at the left sternal border and apex and a fixed split second heart sound. The jugular venous pulsations are elevated with a prominent V-wave, her liver is pulsatile, and she has bilateral lower extremity pitting edema. Her echocardiogram demonstrates retracted and immobile tricuspid and mitral leaflets with severe tricuspid and mitral regurgitation. There is mild pulmonic insufficiency. Her right ventricle is moderately dilated with preserved systolic function. How would you counsel her?
a. Advise that she immediately begin therapy with octreotide as inhibition of serotonin release will result in prompt reversal of her valvular disease.
b. Advise her that given her metastatic carcinoid she is not a candidate for valvular surgery owing to her poor short-term prognosis.
c. Advise her that her valvular disease is unlikely to be related to carcinoid given the involvement of the mitral valve.
d. Advise her that surgical replacement of the valves, while high risk, will improve her survival. Ensure that she has appropriate oncologic follow-up for management options.
10. A 75-year-old obese man is referred to your clinic for further recommendations regarding the following incidental finding on cardiac CT imaging (see figure, arrow). He denies palpitations, syncope, or HF symptoms. What is the most likely diagnosis?
a. Fibroma
b. Lipomatous hypertrophy of the interatrial septum (LHAS)
c. Lipoma
d. Leiomyosarcoma
Answers
1. Answer D: Cardiac myxomas are the most common primary cardiac tumor, accounting for 50% of primary cardiac tumors in adults. Though they can be found anywhere in the heart, the most common location is in the left atrium. Myxomas can present with a classic triad of symptoms including obstructive, embolic, or constitutional symptoms. Only 7% to 10% are associated with autosomal dominant familial syndromes.
2. Answer C: Cardiac papillary fibroelastomas are the second most common primary cardiac tumor and the most common tumor of the cardiac valves. The majority involve the left heart chambers most commonly the aortic valve. They have embolic potential prompting referral for surgery in select cases.
3. Answer D: The Carney complex is characterized by cardiac and extracardiac myxomas, lentigines, nonmyxomatous extracardiac tumors including testicular Sertoli cell tumors, schwannomas, pituitary adenomas, and thyroid tumors. Frequently the Carney complex involves Adrenocorticotropic hormone-independent primary adrenal hypercortisolism and not hypoadrenalism.
4. Answer C: Melanomas have the highest propensity for cardiac metastases with 60% to 70% of cases of metastatic disease being associated with cardiac involvement. Owing to the fact that they are more common malignancies, lung and breast cardiac metastases are numerically more common.
5. Answer E: Leiomyosarcomas are unique amongst primary malignant cardiac tumors in that they predominantly occur in the left heart with 70% to 80% of tumors occurring in the left atrium. They can be differentiated from left atrial myxomas by their broad-based attachment and tendency to extend into the pulmonary veins.
6. Answer D: Both cardiac lipomas and rhabdomyomas can be seen in the context of tuberous sclerosis. Lipomas most commonly have an epicardial location with a narrow stalk and growth into the pericardial space. In some cases they may be intramyocardial and associated with conduction disorders or arrhythmia. Rhabdomyomas are quite rare in the adult population but may complicate tuberous sclerosis. They are typically intramyocardial and are defined by their propensity to regress spontaneously. Given that the patient is asymptomatic, further workup can be deferred and the patient can be followed conservatively with serial echocardiograms. Symptoms suggestive of conduction disease or arrhythmia (e.g., palpitations, syncope, etc.) should be aggressively pursued if they occur and may necessitate resection.
7. Answer B: Immunocompromised hosts including patients with HIV and those status postsolid organ transplantation are at risk of developing primary cardiac lymphomas. Angiosarcomas and rhabdomyosarcomas are diagnostic possibilities but less likely in this context. Mesotheliomas typically present with epicardial/pericardial masses in patients with a history of asbestos exposure. Atrial myxomas are less common in the right atrium but this too is a diagnostic possibility. Importantly, the presence of systemic complaints such as fever and weight loss may accompany both myxomas and malignant primary and secondary cardiac tumors. Tissue diagnosis is critical as unlike other malignant primary cardiac neoplasms, these lymphomas are best managed with attenuation of the immunosuppressive regimen and systemic chemotherapy. As with all primary malignant cardiac tumors, their rarity mandates that an exhaustive evaluation be performed to rule out an extracardiac primary tumor.
8. Answer D: This patient’s tumor is most likely a fibroma given its intramyocardial location, extensive calcification, and the associated malignant arrhythmias. His history of recurrent basal cell carcinomas raises the possibility of the Gorlin complex (basal cell carcinomas, bifid ribs, cardiac fibromas, and mandibular cysts). Cardiac fibromas frequently present with malignant arrhythmias and HF due to obstruction or restrictive filling. Treatment focuses on surgical resection which is curative. In contrast to rhabdomyomas, fibromas are unlikely to regress spontaneously and conservative management is not appropriate.
9. Answer D: In the absence of severe right ventricular dysfunction, patients with severe tricuspid regurgitation secondary to carcinoid have an improved prognosis with valve replacement. Octreotide is a synthetic somatostatin analogue that binds to carcinoid tumor cells and inhibits the production of serotonin and other biologic amines. It is effective in treating the vasomotor symptoms and diarrhea associated with carcinoid syndrome but will not lead to regression of her valvulopathy. Carcinoid tumors are typically indolent, and the short-term prognosis is excellent even in the setting of metastatic disease with 1- and 5-year survival rates of 80% and 60%, respectively for patients undergoing treatment. Carcinoid heart disease typically targets the right-sided valves but in the setting of intracardiac shunts or bronchial tumors, left-sided valves may be affected. In this patient, the fixed splitting of the second heart sound is the result of a small secundum atrial septal defect (ASD).
10. Answer B: The noncontrasted cardiac CT image demonstrates LHAS, a nonneoplastic excessive accumulation of nonencapsulated fat > 2 cm in diameter in the superior and inferior portions of the atrial septum. As seen in this image, there is typically sparing of the fossa ovalis. LHAS is more common in elderly, obese, male patients. The need for surgical resection is extraordinarily uncommon and predicated on the presence of associated arrhythmic or obstructive symptoms.