Heart
Cardiac tumors - benign
Myxoma

Author: Nat Pernick, M.D. (see Authors page)

Revised: 25 April 2018, last major update September 2015

Copyright: (c) 2007-2018, PathologyOutlines.com, Inc.

PubMed Search: Myxoma [title] heart pathology review[ptyp]

Cite this page: Pernick, N. Myxoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/hearttumormyxoma.html. Accessed July 18th, 2018.
Definition / general
  • Most common primary tumor of heart (~40%), although still rare; distinct from soft tissue myxoma
  • Sporadic or familial (see Carney syndrome below)
  • 90% occur in atria, 80% on left side
  • Mean age 50 years
  • Pedunculated tumors may move through AV value at systole; this "wrecking ball" effect may damage valve leaflets
  • Symptoms of ball valve obstruction, emboli, fever / malaise due to IL6 (mediates acute phase response, Chest 2003;123:1379)
  • Associated with HSV infection (Am J Pathol 2003;163:2407)
  • Benign (only rare metastases) but malignant in a sense because often embolizes (30 - 40%) and may cause death; embolization may be related to overexpression of matrix metalloproteinases (Am J Pathol 2005;166:1619); rarely embolizes in toto (Jpn Heart J 2004;45:359)
  • Rarely causes aneurysms (Neurol India 2005;53:216)
  • Stromal cells may arise from multipotent mesenchyme capable of neural and endothelial differentiation with glands representing entrapped foregut rests (Am Heart J 2000;140:134)
  • Carney syndrome / complex: 10% of cases; autosomal dominant with multiple cardiac and extracardiac (skin) myxomas, spotty skin pigmentation, endocrine overactivity, schwannomas, epithelioid blue nevus (Orphanet J Rare Dis 2006;1:21); these patients are younger (mean 24 years), usually men (66% vs. 24% in nonfamilial cases), multicentric (33%, Am J Surg Pathol 1985;9:53); caused by mutations in protein kinase A regulatory subunit 1 alpha (PRKAR1A, Circ J 2005;69:994, Nat Genet 2000;26:89)
Case reports

Metastases:
Treatment
Gross description
  • Usually solitary at fossa ovalis, up to 10 cm, sessile or pedunculated, 41% have surface thrombus
  • Soft, polypoid (particularly when examined under water), pale, lobulated
  • Rarely petrified due to repeated hemorrhage (Arch Pathol Lab Med 1989;113:742)
  • Rarely grows on both sides of fossa ovalis
Gross images

Images hosted on PathOut server:

Case of the Week #454



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Gelatinous tumor attached to
atrial septum by narrow pedicle,
tumor has irregular surface
and nearly fills left atrium
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Irregular surface of
this left atrial mass
caused transient
ischemic attacks
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Portion of atrial septum and tumor with smooth surface

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Cut surface shows marked calcification

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Embolism at iliac bifurcation



Images hosted on other servers:
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Gelatinous tumor attached to
atrial septum by narrow pedicle,
tumor has irregular surface
and nearly fills left atrium
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Portion of atrial septum and tumor with smooth surface

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Emboli of iliac artery



Contributed by Pallavi Khattar, M.D. (New York Medical College at Westchester Medical Center, New York), Puneet Bedi, M.D. (Brookdale University Hospital and Medical Center, New York) and John T Fallon, MD, PhD (New York Medical College at Westchester Medical Center, New York) :
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75 year old woman
Microscopic (histologic) description
  • Complex structures resembling cords, nests, rings or poorly formed glands, often surrounding blood vessels
  • Composed of stellate or globular myxoma cells with abundant eosinophilic cytoplasm, indistinct cell borders, oval nucleus with open chromatin and indistinct nuclei
  • Abundant mucopolysaccharide (myxoid) ground substance containing chondroitin sulfate and hyaluronic acid (Life Sci 2003;73:849)
  • Usually inflammation, hemorrhage
  • Often more cellular and mitotic activity near surface
  • Variable fibrosis (41%), calcification (20%), Gamna-Gandy bodies (17%, identical to those in spleen of sickle cell anemia patients), ossification (8%), extramedullary hematopoiesis (7%, more common in children), mucin forming glands (3%, Indian Heart J 2003;55:182), atypia (3%), thymic rests (1%)
Microscopic (histologic) images

Images hosted on PathOut server:

Contributed by Dr. Ayesha Azam, University Hospital Coventry & Warwickshire (UK) for COW #454

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Perls iron stain

Calretinin




Other images hosted on PathOut server:
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Short cords or syncytia embedded in myxoid matrix

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Multilayered rings of
myxoma cells around
blood vessels are infiltrated
by lymphocytes
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Ring structure with 2 cell layers; #3 with atypia


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Irregular surface fronds
are associated with
emboli and younger
patient age
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Cellular areas near surface

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Central area of bone

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Gamna Gandy bodies

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Extramedullary hematopoiesis


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Thymic rest

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Interface with atrial septum
often shows lymphoid aggregates,
smooth muscle bundles and
thick walled vessels
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Possible cardiac myxoma
(fibrotic mass with
myxoma-type cells)

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A: CD34+ surface cells
B: CD34+ deep cells
C: factor VIII negative myxoma cells (positive vascular control)
D: smooth muscle actin+



Tumors with glandular component
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Glandular structures


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Mucicarmine

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TAlcian blue (pH 2.5)

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CK7

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MNF-116



Emboli
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Intramyocardial coronary artery

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Pulmonary artery



Images hosted on other servers:
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Scattered spindle cells

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Various images

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Blood vessels show mucoid degenerative changes


Contributed by Pallavi Khattar, M.D. (New York Medical College at Westchester Medical Center, New York), Puneet Bedi, M.D. (Brookdale University Hospital and Medical Center, New York) and John T Fallon, MD, PhD (New York Medical College at Westchester Medical Center, New York):
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75 year old woman with edema on bilateral extremities and weight gain; mass in right atrium


Positive stains
Negative stains
Electron microscopy description
  • Features of endothelial, smooth muscle and immature mesechymal cells
  • Cells have numerous cytoplasmic filaments (Cancer 1977;40:2216)
Electron microscopy images

Images hosted on PathOut server:
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Multiple appearing
nuclei with little
ultrastructural
differentiation
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Bundles of intermediate
filaments and rough
endoplasmic reticulum
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Primitive intercellular junction without desmosomes

Differential diagnosis