Vulva
Benign tumors
Mammary type myofibroblastoma

Author: Carlos Parra-Herran, M.D. (see Authors page)

Revised: 26 August 2016, last major update August 2016

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed Search: Mammary type myofibroblastoma vulva
Cite this page: Mammary type myofibroblastoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/vulvamtmyofibroblastoma.html. Accessed March 27th, 2017.
Definition / General
  • Initially described in the breast, myofibroblastoma occurs in a wide range of anatomic locations
  • It rarely involves the lower genital tract, predominantly vagina (less commonly vulva and cervix)
Pathophysiology
  • History of exogenous hormone or tamoxifen exposure has been documented in some cases
Clinical Features
  • Age of presentation ranges from 23 to 80 years
  • Most patients complain of a mass
Prognostic Factors
  • Benign behavior with no recurrences or death after conservative excision
Treatment
  • Local excision is curative
Gross Description
  • Well circumscribed mass, sometimes polypoid
  • Rubbery and whorled cut surface
Micro Description
  • Tumor is well demarcated, without a capsule, and with a sharp interface with the overlying dermis
  • Tumor contains haphazardly oriented fascicles of bland spindle cells
  • Interspersed matrix is composed of hyalinized collagen bundles
  • A variable adipose tissue component is commonly seen
Micro Images

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Breast tumor

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Nodal myofibroblatoma

Positive Stains
Negative Stains
Molecular / Cytogenetics Description
  • Monoallelic loss of FOXO1 / FOX1A1 on 13q14 has been demonstrated in mammary and vulvovaginal myofibroblastoma (Hum Pathol 2012;43:1887)
Differential Diagnosis
  • Cellular angiofibroma: morphologic overlap and similar genetic findings (both have loss of FOX1A1 at 13q14), but cellular angiofibroma has a more prominent vascular component and lacks thick hyalinized collagen bundles
  • Angiomyofibroblastoma: areas of hypo- and hypercellularity, more prominent vascular component (delicate capillary-sized vessels), CD34 negative
  • Aggressive angiomyxoma: prominent myxoid change with hypocellularity; lacks intersecting fascicles and thick hyalinized collagen bundles
  • Metastatic adenocarcinoma from gastrointestinal tract origin: signet ring cells