Breast - nonmalignant
Benign tumors / changes

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

Revised: 24 August 2015, last major update August 2015

Copyright: (c) 2002-2015,, Inc.

PubMed Search: Angiolipoma [title] breast
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
  • Mammography / X-ray: 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
  • 55 year old man (Int J Surg Pathol 2011;19:813)
  • 70 year old woman with firm mass (Radiology 2003;227:773)
  • 73 year old woman with cellular angiolipoma of breast (Breast J 2002;8:47)
  • 75 year old woman with multiple bilateral angiolipomas of breast (Aust N Z J Surg 1982;52:614)
  • Cellular angiolipoma of breast (Mod Pathol 1993;6:497)
  • Treatment
  • Usually simple surgical excision is curative
  • Wide excision may be needed for infiltrative variant
  • Clinical Images
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    Various images

    Micro 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)
  • Micro Images
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    Anastomosing capillaries, inconspicuous endothelial cells (AFIP)

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    Soft tissue (AFIP): mature adipose tissue and prominent vasculature

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    Capillary vessels with microthrombi

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    Courtesy of Dr. Mark R. Wick

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    Breast angiolipoma

    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