Soft tissue
Adipose tissue tumors
Lipoma and variants

Topic Completed: 1 August 2012

Minor changes: 17 September 2020

Copyright: 2002-2020,, Inc.

PubMed Search: Myolipoma

Vijay Shankar, M.D.
Page views in 2019: 3,118
Page views in 2020 to date: 2,511
Cite this page: Shankar V. Myolipoma. website. Accessed October 26th, 2020.
Definition / general
  • Called lipoleiomyoma in uterus
  • Note: myelolipoma is tumor with hematopoietic (including myeloid) elements, often in adrenal gland
  • Very rare tumor of adults in abdomen, retroperitoneum or abdominal wall
  • Other rare sites include eyelid, pericardium, base of tongue
Radiology images

Contributed by Drs. Arno Vanstapel and Raf Sciot, Case #452

CT abdomen frontal

CT abdomen transverse

Case reports
  • Excision
  • Does not recur, metastasize or transform
Gross description
  • Often 9 cm or more, completely or partially encapsulated, yellow-white
Gross images

Contributed by Drs. Arno Vanstapel and Raf Sciot, Case #452

Images hosted on other servers:

Fatty tissue with bands and nodules of firm white tissue

Microscopic (histologic) description
  • Mature adipose tissue and mature (well differentiated) smooth muscle in short fascicles (Stanford University)
  • Variable fibrosis and inflammation
  • No floret cells, no thick walled vessels, no necrosis, no mitotic figures
Microscopic (histologic) images

Contributed by Drs. Arno Vanstapel and Raf Sciot, Case of the Week #452




Images hosted on other servers:

Mature fat and smooth muscle fibers

Low magnification view of myolipoma

Smooth muscle fibers are SMA+ (left), desmin+ (right)

Positive stains
Differential diagnosis
Board review style question #1
Which of the following immunohistochemical stains would help distinguish retroperitoneal myolipoma from a well differentiated liposarcoma invading smooth muscle?

B. HMB45
C. S100
D. Smooth muscle actin
E. Vimentin
Board review answer #1
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