Cardiac tumors - benign
Granular cell tumor

Topic Completed: 1 November 2013

Revised: 26 September 2019

Copyright: 2007-2019, PathologyOutlines.com, Inc.

PubMed Search: Granular cell tumor heart

Nat Pernick, M.D.
Page views in 2018: 223
Page views in 2019 to date: 176
Cite this page: Pernick N. Granular cell tumor. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/hearttumorgranularcelltumor.html. Accessed October 16th, 2019.
Definition / general
  • 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
Gross description
  • Epicardial nodules at base of heart in adults
  • Circumscribed, gray-tan, firm
  • Almost never continuous with nervous tissue
Gross images
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Tumor (arrowheads) overlying
left main coronary artery
near its origin (AO-aorta,
PA-pulmonary artery)
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Circumscribed white
tumor of epicardial
surface overlying
right ventricle
Microscopic (histologic) description
  • 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
Microscopic (histologic) images
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Well demarcated tumor
adjacent to coronary artery
(Movat pentachrome stain)
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Tumor adjacent to left anterior
descending coronary artery with
arterial elastic fibers highlighted
by Movat pentachrome stain
Missing Image

Tumor has ill defined cell
margins, abundant eosinophilic
and granular cytoplasm
and pyknotic nuclei

Images hosted on other servers:

Missing Image

Clusters of granular cells

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PAS and S100

Positive stains
Negative stains
Electron microscopy description
  • Granules are membrane bound autophagic vacuoles with cellular debris
  • May have myelinated and nonmyelinated axon-like structures
Differential diagnosis
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