Heart-tumor

Common tumors are myxoma (30% of all primary cardiac tumors), papillary fibroelastoma (8%), rhabdomyoma, fibroma, hemangioma, lipomatous hypertrophy, AV nodal tumors, other (5% or less each)

In children, common tumors are rhabdomyoma, fibroma and teratoma (Orphanet J Rare Dis 2007;2:11)

References: http://www.cancer.org/downloads/PUB/DOCS/SECTION28/91.pdf

Adenomatoid tumor of the heart

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Very rare

Case reports: incidental 1 cm tumor (AJSP 1997;21:1378)

Micro: cords or tubules of large epithelioid cells without atypia that occasionally branch into anastomosing channels

Micro images:

adrenal gland - various images

epididymis - tubules, cords or nests of epithelioid cells in fibrous stroma; cells have large intracytoplasmic vacuoles, but no atypia #1; #2; cytokeratin AE1/AE3

site unknown - tumor has angiomatous-like spaces

Positive stains: AE1/AE3, CAM 5.2, EMA, calretinin, thrombomodulin (paratesticular tumors-Histopathology 2000;36:109, adrenal tumors-AJSP 2003;27:969)

Negative stains: CEA

Angiomyolipoma of heart

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Very rare

Associated with tuberous sclerosis

Case reports: 48 year old woman with dyspnea and right atrial mass (AJSP 1994;18:1164), massive (34 cm) right atrial tumor (J Formos Med Assoc 1997;96:653)

Gross images: posterior mediastinal tumor is well circumscribed, yellow and fatty

Micro: mixture of blood vessels, smooth muscle and fat

Micro images: kidney - tumor #1; #2; #3; liver - epithelioid angiomyolipoma; mediastinum - mature adipocytes, plump spindle cells and vessels; HHF35+; HMB45+

Positive stains: adipocytes - S100; smooth muscle cells - desmin, actin; most cells - CD117 (diffuse and cytoplasmic, AJSP 2002;26:493), HMB45, NKI-C3/CD63 (Archives 2001;125:751), MelanA/Mart1, microphthalmia transcription factor

EM images: kidney - tumor cells with smooth muscle differentiation adjacent to lipid droplet within an adipocyte (left); various images

DD: renal angiomyolipoma with thrombus extending into right atrium (Urol Int 2001;67:168, Nippon Hinyokika Gakkai Zasshi 1999;90:745)

Atrioventricular node tumor of heart

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Also called cystic tumor of AV node or mesothelioma of AV node, but does not appear to have mesothelial origin

Rare; usually identified at autopsy

May be congenital rests of endodermal origin (Archives 1990;114:1057) or ultimobranchial heterotopia identical to solid cell nests of thyroid (AJCP 2005;123:369)

Associated with other congenital anomalies

Often causes heart block and sudden death

Mean age 38 years, 75% female

Should examine conduction system in all patients with sudden death, particularly if a history of arrhythmia or heart block

Case reports: causing heart block for years before death (AJCP 1975;63:377), causing sudden cardiac death #1 (Archives 2001;125:573), #2 (Am J Forensic Med Pathol 2005;26:349), occurring in atrial septum (Cardiovasc Pathol 1999;8:325), congenital tumors (Cardiovasc Pathol 1999;8:233), with multiple endocrine abnormalities (Pathol Res Pract 1996;192:54)

Treatment: pacemaker implantation, anti-arrhythmic drugs, possibly surgical excision (Heart 2000;83:E6)

Gross: may not be visible due to small size (2 to 20 mm); multicystic lesion in area of atrioventricular node and membranous septum

Gross images: tumor outlined by arrowheads (RA-right atrium, RV-right ventricle, TV-tricuspid valve); figures 1/2: nodule of atrioventricular node; fig 3: elastic and trichrome stains

Micro: must sample conduction system; solid and cystic areas lined by nonciliated, epithelial appearing cuboidal cells (main cells), mixed with occasional clear cells (neuroendocrine or C cells); lumina contains PAS+ diastase resistant material which may calcify; may have inflammatory cells and fibrosis; no smooth muscle, no mitotic figures, no atypia

Micro images: normal anatomy (no tumor) with IAS-interatrial septum (tumors are located inferiorly), TV-tricuspid valve and VS-ventricular septum; large cysts filled with proteinaceous debris; multiple small cysts not visible to naked eye; cysts with irregular shape surrounded by fibrous stroma; cyst may have two cell lining, with inner lining composed of small cuboidal cells; tumor nests and cysts replace muscle bundles in inferior interatrial septum; cuboidal cells and clear, sebaceous-type cells; squamous differentiation and calcification of luminal debris; nests of cells resembling urothelium; cysts lined by squamous epithelium; H&E and AE1/AE3+; various images

Atrioventricular node tumor of heart (continued)

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Positive stains: main cells - CAM5.2, AE1/AE3, 34βE12, CK7, EMA, CEA, CA19.9, p63, bcl2, galectin 3

neuroendocrine or C cells - CAM5.2, AE1/AE3, CEA, calcitonin, chromogranin, synaptophysin, TTF-1

Negative stains: CK20, vimentin, CD31, factor VIII–related antigen, calretinin, estrogen receptor and progesterone receptor

EM: (a) cells form solid nests with well formed basement membranes, cytoplasmic tonofilaments and desmosomes or (b) glandular structures with desmosomes, electron-dense material and short microvilli

DD: bronchogenic cyst (solitary, grossly visible, on epicardial surface, smooth muscle present), mesothelial cyst (larger, unilocular, on surface of heart), teratoma (has neural or other ectodermal structures, Pediatr Pathol 1994;14:913)

Benign fibrous histiocytoma of heart

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Rare in heart

Case reports: 4 month old boy who died due to large cardiac tumor (Z Rechtsmed 1990;103:335)

Micro: storiform pattern of spindle cells and lipid laden histiocytes; no mitotic figures, no pleomorphism

Micro images: cellular tumor without mitotic figures; tracheal tumor

Positive stains: alpha-1-antichymotrypsin, lysozyme, vimentin, factor XIIIa

Negative stains: CD68, CD34

Blood cyst of heart

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Congenital cyst found on endocardium, particularly along lines of closure of heart valves

More common on mitral and tricuspid valves

Actually diverticula (invagination of atrial endothelium into atrioventricular valves or ventricular endothelium into semilunar valves)

Incidental findings in 50% of infants under age 2 months on cardiac valves; rare after age 2 years

Rarely causes ventricular or valvular obstruction

Case reports: acquired after surgery (J Am Soc Echocardiogr 2003;16:377), on pulmonary valve (Hum Path 1997;28:252)

Gross: usually 3 mm or less; may be blue; 50% are multiple, may have up to 20 cysts

Gross images: 4 mm cyst is incidental finding on tricuspid valve of 4 month old who died of unrelated causes; blood cyst of mitral value; seen with dissecting microscope

Micro: blood filled cystic cavity with fibromyxoid wall lined by flattened or cobblestone-shaped endothelium; filled with nonorganized blood

Micro images: non-organized blood in a sac lined by endothelium; cyst wall (fig 3)

Calcified amorphous tumor of heart

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Endocardial based intracavity cardiac mass

Mean age 52 years

Clinically simulates neoplasm

Case reports: 2 cm mass in right ventricular wall involving chordae tendineae of tricuspid valve (Cardiovasc Pathol 2006;15:299), hemodialysis patients (Kyobu Geka 2006;59:851)

Treatment: excision is curative, although residual calcium may persist

Gross: firm, yellow-white, partially calcified

Micro: nodular calcium with degenerating blood elements and chronic inflammation

DD: calcified thrombi

References: Hum Path 1997;28:601

Endocardial fibroelastosis of heart

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Rare

Focal or diffuse fibroelastic thickening of mural left ventricular endocardium

Usually ages 0-2 years

Focal cases have no symptoms; diffuse cases may cause rapid cardiac decompensation and death (Transplant Proc 2006;38:1511, Am J Forensic Med Pathol 1999;20:357)

Associated with (a) cardiac anomaly, such as aortic valve obstruction, or response to other chronic prenatal cardiac stress (J Clin Pathol 1991;44:576); (b) congenital heart block and maternal anti-Ro or anti-La autoantibodies (Circulation 2002;105:843), (c) mumps or other viral infection (Circulation 1997;95:133)

Declining incidence, with almost no new cases, may be due to declining incidence of mumps (eMedicine)

Case reports: fibroelastosis in neonate with no other cardiac pathology (J Clin Pathol 1992;45:1042)

Treatment: heart transplant

Gross images: pale opaque endocardium #1; #2; #3; marked endocardial thickening of left ventricle; thickened endocardium; neonate-A: endocardium of left ventricle is grossly thickened, and extends into myocardial sinusoids (arrow); B: von Gieson elastin stain shows endocardium is composed of bands of collagen and elastic fibers

Micro: increased fibroelastic tissue in endocardium and subendocardium; myocardium usually normal

Micro images: low power; von Gieson elastic stain #1; #2; trichrome stain shows marked fibrous thickening of endocardium #1; #2

References: OMIM 305300

Fibroma of heart

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Rare, but is common among cardiac tumors in children

Benign, congenital, probably a hamartoma; rare cases may represent fibromatosis with aggressive behavior

Presents with heart failure or cyanosis in 1/3, syncope or arrhythmia in 1/3, incidental/asymptomatic in 1/3

Found in 10% of Gorlin’s syndrome patients (nevoid-basal cell carcinoma syndrome)

Case reports: 8 month old boy with nevoid basal cell carcinoma syndrome (Tex Heart Inst J 2006;33:88), sudden death in 7 month old girl (J Forensic Sci 2000;45:731), sudden death in 6 year old boy (Circulation 2000;101:E168)

Treatment: excision, possibly transplant (Curr Opin Cardiol 2000;15:121)

Gross: discrete bulging mass, nearly always solitary, often calcification

Gross images: large septal mass on anterior and right lateral border #1; #2; #3 (homogeneous mass was easily shelled out); large circumscribed mass in lateral right ventricular wall compresses right ventricular cavity; ventricular mass; intraoperative image

Micro: bland fibroblasts and collagen; calcification common; more cellular in infants and children; mitotic figures in infants only; margin is infiltrative; occasionally perivascular lymphocytes and histiocytes, elastic fibers, myxoid stroma

Micro images: cellular lesion in infant with perivascular lymphocytes and minimal collagen; tumor with collagen deposition; prominent fibrous tissue; spindle cells in collagen matrix; fibroblastic cells; trichrome #1 shows abundant collagen (more common in older children/adults); #2 shows infiltrative margin-a; infiltrative margin-b; #3 shows cardiac muscle at periphery, central tumor cells in biopsy; #4; #5; von Gieson elastin stain shows elastic fibers; calcification

EM: fibroblasts with extensive endoplasmic reticulum but few cellular organelles; incompletely developed/absent basement membrane, ramifying cytoplasmic processes, central nucleus with distinct nucleolus; also cells of intermediate differentiation with smooth muscle myofilaments

DD: fibrosarcoma (rare in infants/young children, prominent mitotic activity), inflammatory pseudotumor / myofibroblastic tumor (endocardial lesions covered by fibrin; stellate tumor cells have obvious nucleoli, more prominent inflammation, occasional mitotic figures and necrosis, Ann Diagn Pathol 2001;5:335), fibrous histiocytoma (extremely rare in heart, lipid-laden histiocytes), scar (grossly does not bulge)

Granular cell tumor of heart

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Very rare

Usually incidental finding at autopsy that may be overlooked

Benign tumor of Schwann cells, not myocytes (Archives 1976;100:276)

Only rarely has malignant behavior in heart

Case reports: multicentric tumor of skin and heart (Ann Thorac Surg 1994;57:1653), malignant tumor with multiple foci in myocardium (AJSP 1982;6:665)

Gross: epicardial nodules at base of heart in adults; circumscribed, gray-tan, firm; almost never continuous with nervous tissue

Gross images: tumor (arrowheads) overlying left main coronary artery near its origin (AO-aorta, PA-pulmonary artery); circumscribed white tumor of epicardial surface overlying right ventricle

Micro: tumor cells merge with cardiac myocytes; have ill defined cell margins, abundant eosinophilic and granular cytoplasm with bland pyknotic nuclei, similar to granular cell tumors elsewhere

Micro images: well demarcated tumor adjacent to coronary artery (Movat pentachrome stain); tumor adjacent to left anterior descending coronary artery with arterial elastic fibers highlighted by Movat pentachrome stain; tumor has ill defined cell margins, abundant eosinophilic and granular cytoplasm and pyknotic nuclei

Breast - cells have abundant, eosinophilic granular cytoplasm #1; #2

Esophagus - clusters of granular cells; PAS and S100

Positive stains: S100, PAS+ diastase resistant granules; also neuron specific enolase

Negative stains: neurofilament, GFAP

EM: granules are membrane bound autophagic vacuoles with cellular debris; may have myelinated and nonmyelinated axon-like structures

DD: disseminated granular cell epulis (tumor of gingiva of infants that rarely disseminates)

Hamartoma of mature cardiac myocytes

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Rare

Case reports: 24 year old man (Mod Path 1998;11:496), 33 year old man with shortness of breath (Rev Esp Cardiol 2005;58:450), 33 year old patient with tachycardia (Ann Thorac Surg 2001;71:1673)

Gross: resembles hypertrophic cardiomyopathy but has localized masses or multiple discrete masses, usually in right ventricle or atrium; no septal asymmetry (Hum Path 1998;29:904)

Gross images: right ventricular mass

Micro: discrete but unencapsulated nodules of marked myocyte hypertrophy with disorganization (resembles hypertrophic cardiomyopathy), focal scarring and thickened intramural arteries; no myocyte vacuoles

Micro images: disorganized cardiac cells with prominent nuclei; haphazard hypertrophied myocytes and fibrosis

EM: abundant and disorganized myofilaments; normal intercellular junctions

DD: rhabdomyoma (myocyte vacuoles), oncocytic cardiomyopathy

Hemangioma of heart

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Rare; <5% of benign cardiac tumors

All ages

30% are multiple

Usually asymptomatic, but may cause sudden death or significant cardiac dysfunction by displacing large portions of atria and ventricles

Case reports: necrotic tumor with DIC (Hong Kong Med J 2005;11:308), 49 year old with left atrial tumor (Braz J Cardiovasc Surg 2005;20(4)), with papillary endothelial hyperplasia and liver involvement (Heart 2004;90:e49)

Treatment: complete excision if possible

Gross images: right atrial tumor shows hemorrhage and dilated vessels; left ventricular tumor; tan bosselated mass

Micro: types are capillary (small vessels) or cavernous (multiple dilated thin walled vessels) or arteriovenous (thick walled, dysplastic malformed arteries and veins); no necrosis, no mitotic figures, no atypia; intramural tumors may contain adipose or fibrous tissue

Micro images:

capillary - small vascular channels #1; #2; mixed capillary-cavernous #1; #2; #3; #4; #5; muscle specific actin outlines vascular channels

cavernous - focus of papillary endothelial hyperplasia; dilated vascular channels; intramural tumor

DD: angiomatosis (vessels of various sizes with variable wall thickness, adipose tissue and skeletal muscle, Int Heart J 2006;47:469), myxoma (hemangiomas may have myxoid background, but lack myxoma cells or ring structures), angiosarcoma (atypia present)

References: Radiographics 2000;20:1073, Am J Cardiovasc Pathol 1990;3:283

Inflammatory pseudotumor / inflammatory myofibroblastic tumor of heart

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Previously called plasma cell granuloma

Extremely rare

Usually age 2 months to 17 years

May be intravascular in infants (Pediatr Dev Pathol 2002;5:400)

Case reports: 15 year old boy and 5 month old girl (Archives 1996;120:549), 2 month old boy with multiple tumors (Ann Thorac Surg 2006;82:1531), 72 year old woman (Ann Thorac Surg 2003;75:1971), 55 year old woman with sudden death due to tumor (Forensic Sci Int 1991;49:89)

Treatment: excision, possibly steroids (Pediatr Cardiol 2004;25:406); may recur or continue to grow locally, but no distant metastases (AJSP 1995;19:859)

Gross: up to 8 cm

Micro: spindle cells larger than fibroblasts with obvious nucleoli, inflammatory cells, prominent vasculature, variable myxoid stroma; occasional mitotic figures and necrosis

Micro images: polymorphous inflammatory infiltrate (fig 3); breast tumor-various images; liver tumor-various images; lung tumor shows inflammatory cells and myofibroblasts

Positive stains: smooth muscle actin

Negative stains: desmin, S100, CD34, p53 (Ann Diagn Pathol 2001;5:335)

Lambl’s excrescence of heart

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Also called valvular strands

Common finding in elderly patients

Small filiform / papillary processes that are age-related; may be organized mural thrombi at site of minor endothelial damage

Associated with stroke, particularly among younger patients (Stroke 1997;28:2185)

Aortic/pulmonic valves: most common at nodules of Aranti, along lines of closure and free cuspal edges

Tricuspid/mitral valves: at site of valve closure on atrial surface

Case reports: causing embolic stroke (Nervenarzt 2006;77:1492), causing transient ischemic attack (An Med Interna 2006;23:181)

Gross images: aortic valve

Micro: connective tissue / fibrin covered by endothelium

Micro images: fingerlike projection extending from valve surface without branching

DD: papillary fibroelastoma (larger, more gelatinous, located away from lines of closure and free edges and on endocardial surfaces of atria and ventricles)

References: Am J Cardiol 1986;58:1223

Lipoma of heart

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8-12% of primary tumors of heart and pericardium

Usually on epicardium and asymptomatic

May create ball-valve obstructions or produce arrhythmia

Called lipomatous hypertrophy if in atrial septum

Case reports: massive left atrial lipoma occupying pericardial space (Jpn Heart J 2004;45:715), symptomatic tumor of right atrial free wall (Tex Heart Inst J 1998;25:152), interventricular septum (ASAIO J 2006;52:e35), hibernoma in right atrium (Heart Surg Forum 2006;9:E623)

Gross: may be poorly encapsulated but often circumscribed; spherical or elliptical mass of homogeneous yellow fat

Gross images: circumscribed tumor at base #1; #2; well circumscribed yellow mass; 5 cm lobulated mass; left ventricular lipoma

Micro: usually encapsulated, composed of mature fat, may contain trapped myocytes; usually no brown fat cells

Micro images: mature adipose tissue with trapped myocytes (fig 5)

References: Hum Path 2006;37:1245

Lipomatous hamartoma of heart valves

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Rare

Usually mitral or tricuspid valve

Case reports: tricuspid valve (Clin Cardiol 1991;14:262), fibrolipoma of tricuspid valve (South Med J 1996;89:1018), aortic valve (Jpn J Thorac Cardiovasc Surg 2005;53:577), with blood cysts (J Am Soc Echocardiogr 1998;11:832)

Treatment: may need to replace valve due to involvement of papillary muscle or adjacent atrial tissue

Micro: mature fat and fibrous tissue; no encapsulation

Lipomatous hypertrophy of cardiac intraatrial septum

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Rare (0.6% of cardiac tumors); usually age 60+ years

Associated with increased epicardial fat (heart floats in water), mild to severe obesity

Symptoms include congestive heart failure, atrial fibrillation, supraventricular tachycardia, syncope, sudden unexpected cardiac death (Archives 2006;130:397)

Often diagnosed at autopsy (Cesk Patol 2006;42:182)

“Hypertrophy” is a misnomer because mass is due to increased fat cells, not hypertrophied myocytes

Treatment: weight loss, not surgery (Heart 2004;90:e66)

Gross: unencapsulated mass usually confined to atrium; resembles brown fat; associated with cardiac hypertrophy; septal thickness is 2 to 7 cm (normal is < 1 cm); fossa ovalis is usually spared

Gross images: fatty deposit superior to fossa ovalis; huge fatty tumor of atrial septum sparing fossa ovalis; tumor adjacent to epicardial fat

Micro: multivacuolated fatty infiltration more than 2 cm thick in atrial septum; cells have central nuclei without atypia; some fat cells resemble brown fat and fat cells in malnourished patients; usually atypical and hypertrophied myocytes (AJSP 1996;20:678); variable bands of collagen and chronic inflammatory infiltrates; no mitotic figures, no signet ring structures, no enlarged hyperchromatic and indented nuclei in fat cells

Micro images: mixture of normal fat, vesicular fat and hypertrophied myocytes #1; #2; #3; #4; gross and micro images

EM: abundant mitochondria in vesicular fat cells

DD: myxoma (has stellate or globular cells, myxoid areas, no fat, no hypertrophied myocytes), lipoma (encapsulated, no muscle fibers), liposarcoma (lipoblasts have large clear vacuoles and hyperchromatic indented nuclei)

References: AJCP 1979;72:785, Hum Path 2006;37:1245

Lipomatous infiltration of heart

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Also called fatty heart

Heart may float in water at autopsy

Associated with obesity and lipomatous infiltration of atrial septum