General
=========================================================================

• Only 1-3% of vulvar tumors are sarcomas
• Of these, leiomyosarcomas are the most common type

Epidemiology
=========================================================================

• Usually diagnosed in women older than 40 years of age, but may be found in younger women

Sites
=========================================================================

• Most common site is labia majora

Etiopathology
=========================================================================

• Arises from smooth muscle of vasulature, erectile tissues, arrector pili muscles or round ligaments

Clinical features
=========================================================================

• Non-specific symptoms include itching and redness
• Usually slow growing and painless
• Rarely has rapid growth, more common during pregnancy

Diagnosis
=========================================================================

• 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
=========================================================================

• 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
=========================================================================

• 36 year old woman with myxoid leiomyosarcoma of vulva during pregnancy (Int J Gynecol Cancer 2004;14:172)
• 47 year old woman (Indian J Pathol Microbiol 2008;51:448)
• 50 year old woman with tumor masquerading as Bartholin gland duct cyst (Proc (Bayl Univ Med Cent) 2014;27:25)
• 52 year old woman with tumor in Bartholin's gland area (Arch Gynecol Obstet 2009;279:171)
• 85 year old woman with myxoid leiomyosarcoma of vulva (Gynecol Oncol 2005;96:548)
• Myxoid leiomyosarcoma of Bartholin gland (Obstet Gynecol 2014;124:433)
• Rare case of vulval leiomyosarcoma (J Obstet Gynaecol 2011;31:675)

Treatment
=========================================================================

• 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
=========================================================================

Whorly white cut surface

Micro 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

Micro images
=========================================================================

     

Necrosis

Spindle cell fascicles

Diffuse nuclear pleomorphism

SMA+

Positive stains
=========================================================================

• Desmin, smooth muscle actin, muscle-specific actin, estrogen receptor, progesterone receptor, vimentin

Focal or weak staining
=========================================================================

• S100 and cytokeratin

Negative stains
=========================================================================

• CD34, CD117, DOG1

Differential diagnosis
=========================================================================

• Dermatofibrosarcoma protuberans: CD34+, smooth muscle markers usually negative (Am J Surg Pathol 2010;34:393)
• Epithelioid sarcoma
• Fibrosarcoma: herring bone pattern, smooth muscle markers usually negative
• Gastrointestinal stromal tumor: CD117+, DOG1+ (Oncol Lett 2011;2:797)
• Leiomyoma
• Melanoma
• Undifferentiated sarcoma or malignant fibrous histiocytoma: diagnosis of exclusion, smooth muscle markers usually negative

Additional references
=========================================================================

• Eur J Obstet Gynecol Reprod Biol 1994;56:181, Eur J Gynaecol Oncol 2012;33:306, Obstet Gynecol 1979;53:213, Gynecol Oncol 1992;46:384

This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.

All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at copyrightPathOut@gmail.com with any questions (click here for other contact information).