Breast - nonmalignant
Benign tumors / changes
Angiolipoma

Author: Monika Roychowdhury, M.D. (see Authors page)

Revised: 17 August 2018, last major update August 2015

Copyright: (c) 2002-2018, PathologyOutlines.com, Inc.

PubMed Search: Angiolipoma [title] breast
Cite this page: Roychowdhury, M. Angiolipoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/breastangiolipoma.html. Accessed September 25th, 2018.
Definition / general
  • Nodule composed of mature adipocytes, thin walled vessels and fibrin thrombi (essentially a lipoma with prominent vascular features)
Terminology
  • Described by Bowen a century ago and established as a pathologic entity by Howard and Helwig in 1960 (Arch Dermatol 1960;82:924)
Sites
  • Usually subcutaneous nodules on extremities and trunks of young adults, rare in breast
  • When in breast, it develops in subcutaneous fat, just in front of the pectoral fascia muscle and not within the breast parenchyma itself
Etiology
  • Unknown
Clinical features
  • Usually no pain, unlike angiolipoma elsewhere
  • Rarely exceeds 2 cm diameter
Radiology images
  • Mammography / Xray: no typical appearance, may appear as focal increased density or an ill defined mass / nodule
  • Ultrasound: well circumscribed hyperechoic mass without posterior enhancement
Prognostic factors
  • Not known to undergo malignant transformation
Case reports
Treatment
  • Usually simple surgical excision is curative
  • Wide excision may be needed for infiltrative variant
Microscopic (histologic) description
  • Circumscribed mass composed of mature adipose tissue mixed with capillary sized interanastomosing vascular proliferation
  • Intraluminal fibrin thrombi are common
  • Periphery of the lesion has a tendency for higher vascular density
  • The World Health Organization (WHO) 2002 classification of tumors of soft tissue and bone subclassifies into low vascular density (low vascularity) and cellular (50% or more vascular tissue, 25 - 30% of lesions, Int J Surg Pathol 2011;19:35, Breast J 2002;8:182)
Microscopic (histologic) images

Images hosted on PathOut server:

AFIP images:
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Anastomosing
capillaries,
inconspicuous
endothelial cells

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Soft tissue: mature adipose tissue and prominent vasculature


Contributed by Dr. Mark R. Wick:


Images hosted on other servers:
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Capillary vessels with microthrombi

Cytology description
  • Hypocellular, mature adipose tissue in hemorrhagic background
  • Rare, benign appearing spindled endothelial cells in clusters or strands resembling capillaries (Cancer 1999;87:359)
Positive stains