Soft tissue
Fibroblastic / myofibroblastic tumors

Author: Komal Arora, M.D. (see Authors page)

Revised: 12 August 2016, last major update July 2014

Copyright: (c) 2002-2016,, Inc.

PubMed Search: Angiomyofibroblastoma

Cite this page: Angiomyofibroblastoma. website. Accessed October 24th, 2016.
Definition / General
  • Benign, well-circumscribed myofibroblastic tumor, usually in vulva
  • May overlap with cellular angiofibroma
  • First described in 1992 (Am J Surg Pathol 1992;16:373)
Clinical Features
  • Uncommon slow growing painless mass, usually females of reproductive age
  • Usually vulvar, 10 - 15% in vagina
  • Also scrotum or paratesticular soft tissue in men (median age 57 years)
Case Reports
  • Excision, only rarely recurs, does not metastasize
Gross Description
  • Well circumscribed but not encapsulated, usually 5 - 7 cm or less, tan-pink soft cut surface, no necrosis
Gross Images

Images hosted on PathOut servers:

Scrotum, courtesy of Mark R. Wick, M.D.

Micro Description
  • Thin fibrous pseudocapsule, alternating hyper- and hypocellular areas with prominent thin walled and ectatic vessel in edematous stroma (Mod Pathol 1996;9:284)
  • Round to spindled tumor cells have eosinophilic cytoplasm and often bi- or multi-nucleation
  • May have plasmacytoid or epithelioid morphology, or rarely show degenerative changes
  • Tumor cells are concentrated around vessels
  • Mast cells common
  • 10% have mature adipose tissue
  • No / rare mitotic figures, no / rare red blood cell extravasation, no atypia
  • Most menopausal patients have less cellularity, less edema but more fibrosis and vessel wall hyalinization
Micro Images

Images hosted on PathOut servers:

Scrotum (left) and vulva (right two), courtesy of Mark R. Wick, M.D.

Images hosted on other servers:

Arising from posterior perivesical space

Numerous capillary-like vascular channels

Positive Stains
Negative Stains
Electron Microscopy Description
  • Myofibroblastic and fibroblastic features
Differential Diagnosis
  • Aggressive angiomyxoma: not circumscribed, > 5 cm, less cellular, less vascular but vessels are large and thick walled, stromal mucin and RBC extravasation are present, infrequent plump stromal cells, usually actin negative
  • Cellular angiofibroma: more cellular uniformly, perivascular hyalinization and large, thick walled vessels, usually actin/desmin negative
  • Epithelioid leiomyoma: more cellular, no biphasic pattern, usually no binucleation, no / rare mast cells