Malignant neoplasms

Author: Priya Nagarajan, M.D., Ph.D. (see Authors page)
Editor: Sara Peters, M.D., Ph.D.

Revised: 9 October 2017, last major update December 2014

Copyright: (c) 2002-2017,, Inc.

PubMed Search: Leiomyosarcoma vulva

Page views in 2018: 430
Page views in 2019 to date: 31
Cite this page: Nagarajan, P. Leiomyosarcoma. website. Accessed January 22nd, 2019.
Definition / general
  • Only 1 - 3% of vulvar tumors are sarcomas
  • Of these, leiomyosarcomas are the most common type
  • Usually diagnosed in women older than 40 years of age but may be found in younger women
  • Most common site is labia majora
  • Arises from smooth muscle of vasulature, erectile tissues, arrector pili muscles or round ligaments
Clinical features
  • Nonspecific symptoms include itching and redness
  • Usually slow growing and painless
  • Rarely has rapid growth, more common during pregnancy
  • Diagnostic criteria for vulvar smooth muscle neoplasm as leiomyosarcoma (requires 3 - 4 features, Am J Surg Pathol 1996;20:779):
    • Diameter: > 5 cm
    • Margins: at least focally infiltrative
    • Mitotic rate: > 5 mitotic figures per 10 HPF
    • Cytologic atypia: moderate to severe
  • If one of these features, classify as leiomyoma; if 2 features, classify as atypical leiomyoma
Radiology description
  • CT scan or MRI to assess size and extent of tumor; essential for management
Prognostic factors
  • Poor prognostic factors include:
    • Mitotic rate: > 10 mitotic figures per 10 HPF
    • Local recurrence
    • Distant metastases, frequently to lung
Case reports
  • Management is usually surgical, ranging from local resection to hemivulvectomy
  • Inguinal lymph nodes may be sampled
  • Adjuvant chemotherapy, radiation and hormonal therapy may be used
Gross description
  • Usually well circumscribed and soft
  • Cut surface is usually fleshly, tan to yellow or gray
  • May have areas of hemorrhage, cystic or mucoid changes
  • Obviously necrosis is not common
Gross images

Images hosted on other servers:
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Whorly white cut surface

Microscopic (histologic) description
  • Usually interlacing fascicles of spindle cells
  • Herring bone, storiform and plexiform patterns may be present focally
  • Perinuclear cytoplasmic vacuoles, characteristic of smooth muscle differentiation, are usually present at least focally
  • Cigar shaped nuclei; atypical features of hyperchromasia to severe pleomorphism may be seen
  • Foci of epithelioid cells may be identified
  • Extensive myxoid changes may be seen in background
  • Mitoses, including atypical mitotic figures
  • Rarely coagulative necrosis
Microscopic (histologic) images

Images hosted on other servers:

Images contributed by Dr. Priya Nagarajan:

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Spindle cell fascicles

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Diffuse nuclear pleomorphism

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Focal or weak staining
Negative stains
Differential diagnosis