Vulva, vagina & female urethra
Mesenchymal neoplasms
Angiomyofibroblastoma


Topic Completed: 17 November 2020

Minor changes: 17 November 2020

Copyright: 2002-2020, PathologyOutlines.com, Inc.

PubMed Search: Vulva angiomyofibroblastoma

David B. Chapel, M.D.
Jennifer A. Bennett, M.D.
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Cite this page: Chapel DB, Bennet J. Angiomyofibroblastoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/vulvaangiomyofibroblastoma.html. Accessed December 5th, 2020.
Definition / general
  • Angiomyofibroblastoma is a benign, site specific, soft tissue tumor of the lower genital tract with alternating hypo and hypercellular zones, bland spindle to epithelioid cells and abundant vessels
Essential features
  • Benign lower genital tract tumor, seen predominantly in women
  • Alternating hypo and hypercellular zones, comprised of bland plump spindle to epithelioid cells clustered around abundant small, thin walled vessels
  • No specific immunophenotypic or molecular features reported
  • Local excision curative; recurrences exceptionally rare
ICD coding
  • ICD-10:
    • D21.9 - benign neoplasm of soft tissue, unspecified
    • D23.9 - benign neoplasm of skin, unspecified
    • D28.0 - benign neoplasm of vulva
    • D28.1 - benign neoplasm of vagina
Epidemiology
Sites
Pathophysiology
Clinical features
Diagnosis
  • Diagnosis typically follows complete local excision of a clinically benign appearing mass
Radiology description
Radiology images

Images hosted on other servers:
Vaginal angiomyofibroblastoma: ultrasound Vaginal angiomyofibroblastoma: ultrasound

Vaginal ultrasound

Vaginal angiomyofibroblastoma: MRI Vaginal angiomyofibroblastoma: MRI

Vaginal MRI

Vulvar angiomyofibroblastoma: MRI

Vulvar MRI

Prognostic factors
Case reports
Treatment
Clinical images

Images hosted on other servers:
Intraoperative images Intraoperative images Intraoperative images Intraoperative images Intraoperative images

Intraoperative images

Preoperative image

Preoperative image

Gross description
Gross images

Images hosted on other servers:
Gross specimen Gross specimen

Gross specimen

Microscopic (histologic) description
  • Well circumscribed, noninfiltrative
  • Fibrous pseudocapsule in a subset (Am J Surg Pathol 1992;16:373)
  • Characteristic alternating hypo and hypercellular zones (Am J Surg Pathol 1992;16:373)
  • Tumor cells:
    • Spindle to epithelioid to plasmacytoid myofibroblastic cells
    • Typically bland chromatin and inconspicuous nucleoli; scattered mildly atypical cells in a minority (Am J Surg Pathol 1992;16:373)
    • Bland multinucleated cells common (Am J Surg Pathol 1992;16:373)
    • Mitoses rare or absent; no atypical mitoses
  • Tumor stroma and vasculature:
    • Lacks prominent stromal mucin
    • Hypocellular foci show edematous stroma with scattered fine to thick bands of stromal collagen
    • In hypocellular foci, tumor cells appear randomly distributed
    • In hypercellular foci, tumor cells congregate around small, irregularly distributed, thin walled vessels
    • Occasional larger vessels interspersed
    • Mast cells typically conspicuous
    • Adipocytic differentiation in ~ 25 - 50% (Mod Pathol 1996;9:284, Hum Pathol 1997;28:1046)
  • Rare cases with predominant adipocytic differentiation = lipomatous variant of angiomyofibroblastoma (Hum Pathol 1997;28:1046, Hum Pathol 2014;45:1647, Int J Gynecol Pathol 2015;34:204)
  • Rare tumors show mixed features of angiomyofibroblastoma and aggressive angiomyxoma; should be managed like aggressive angiomyxoma (Histopathology 1997;30:3)
  • Sole case with sarcomatous transformation showed hypercellular foci with cytologic atypia, increased mitoses and lymphovascular invasion (Am J Surg Pathol 1997;21:1104)
Microscopic (histologic) images

Contributed by David B. Chapel, M.D.
Alternating cellularity

Alternating cellularity

Spindle cells

Spindle cells

Epithelioid cells

Epithelioid cells

Multinucleated cells

Multinucleated cells

Virtual slides

Images hosted on other servers:
Vulvar: focal adipocytic differentiation

Vulvar, focal adipocytic differentiation

Vulvar: lipomatous variant

Vulvar, lipomatous variant

Vaginal: focal adipocytic differentiation

Vaginal, focal adipocytic differentiation

Electron microscopy description
  • Features consistent with myofibroblastic differentiation (Am J Surg Pathol 1992;16:373)
    • Stromal cells surrounded by incomplete basal lamina
    • Well developed, rough endoplasmic reticulum and Golgi apparatus
    • Abundant intermediate filaments and pinocytotic vessels
    • Nucleus with delicate heterochromatin
Molecular / cytogenetics description
Sample pathology report
  • Vulva, mass, local excision:
    • Angiomyofibroblastoma (3.5 cm) (see comment)
    • Comment: Margins are negative.
Differential diagnosis
  • Aggressive angiomyxoma:
    • Typically large (most > 10 cm)
    • Infiltrative
    • More uniformly hypocellular
    • No perivascular congregation of cells
    • Tumor cells more uniformly spindled (versus epithelioid)
    • Perivascular myoid bundles characteristic
    • Red blood cell extravasation common
    • HMGA2 positive
    • FISH shows HMGA2 rearrangement in a subset (Genes Chromosomes Cancer 2007;46:981)
  • Leiomyoma:
    • More uniformly cellular
    • Tumor cells show cigar shaped nuclei and eosinophilic cytoplasm
    • Larger, thick walled vessels
    • Often has coagulative necrosis
    • SMA, desmin and caldesmon positive
  • Solitary fibrous tumor:
    • More common in extragenital sites
    • Prominent staghorn (hemangiopericytoma-like) vessels
    • Thick, keloid-like stromal collagen bands
    • CD34 and STAT6 positive
    • Intrachromosomal NAB2-STAT6 translocation on chr 12
  • Superficial angiomyxoma:
    • More uniformly hypocellular
    • No perivascular congregation of cells
    • Prominent stromal mucin, often with acellular mucin clefts / pools
    • Stromal neutrophils conspicuous
Board review style question #1

On a routine exam, a 46 year old woman was found to have a 3 cm, painless mass on her labia majora. Her gynecologist suspected a Bartholin cyst and performed a conservative local excision. A representative photomicrograph from the lesion is shown. The lesion was grossly and microscopically well circumscribed but the surgical margin was focally positive. By immunohistochemistry, the tumor cells were positive for desmin, ER and PR. Which of the following statements about this lesion is true?

  1. Approximately 10% experience distant metastasis
  2. Conservative local excision is considered curative
  3. HMGA2 IHC is positive in ~ 90%
  4. If surgical margins are positive, local recurrence risk exceeds 50%
  5. Stromal neutrophils are found in virtually all such lesions
Board review answer #1
B. Conservative local excision is considered curative. This is an angiomyofibroblastoma

Comment Here

Reference: Angiomyofibroblastoma
Board review style question #2

Which of the following statements about angiomyofibroblastoma is true?

  1. Abundant, thick walled hyalinized vessels are characteristic
  2. At low magnification, alternating hypo and hypercellular zones are characteristic
  3. Men and women are affected in approximately equal numbers
  4. Rb IHC is negative, reflecting underlying RB1 / FOXO1 (chr 13q14) deletion
  5. The vagina is affected approximately 3 times as often as the vulva
Board review answer #2
B. At low magnification, alternating hypo and hypercellular zones are characteristic

Comment Here

Reference: Angiomyofibroblastoma
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