Vulva, vagina & female urethra

Mesenchymal neoplasms

Epithelioid sarcoma


Editorial Board Member: Ricardo R. Lastra, M.D.
Editor-in-Chief: Debra L. Zynger, M.D.
David B. Chapel, M.D.
Jennifer A. Bennett, M.D.

Topic Completed: 30 November 2020

Minor changes: 1 February 2021

Copyright: 2002-2021, PathologyOutlines.com, Inc.

PubMed Search: "Epithelioid sarcoma" vulva

David B. Chapel, M.D.
Jennifer A. Bennett, M.D.
Page views in 2020: 2,238
Page views in 2021 to date: 2,048
Cite this page: Chapel DB, Jennifer B. Epithelioid sarcoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/vulvaepithelioidsarcoma.html. Accessed October 25th, 2021.
Definition / general
  • Epithelioid sarcoma of the vulva and deep pelvic soft tissue is a rare malignant neoplasm characterized by SMARCB1 / INI1 deletion
  • Most vulvar and pelvic epithelioid sarcomas are of the proximal type and show more aggressive clinical behavior than distal type (classical) epithelioid sarcoma
Essential features
  • In vulva and pelvic soft tissues, proximal type epithelioid sarcoma > distal type
  • Proximal type epithelioid sarcoma: sheets or nests of epithelioid to rhabdoid cells with nuclear atypia
  • Positive immunostains: CK, EMA, CD34 (~ 50%)
  • SMARCB1 / INI1 deletion in > 90%, resulting in SMARCB1 / INI1 loss by IHC
  • Frequent local recurrence, lymph node metastasis, distant metastasis (especially to lung) and death
ICD coding
  • ICD-10:
    • C49 - malignant neoplasm of other connective and soft tissue
      • C49.5 - malignant neoplasm of connective and soft tissue of pelvis
      • C49.9 - malignant neoplasm of connective and soft tissue, unspecified
    • C51 - malignant neoplasm of vulva
      • C51.0 - malignant neoplasm of labium majus
      • C51.1 - malignant neoplasm of labium minus
      • C51.2 - malignant neoplasm of clitoris
      • C51.8 - malignant neoplasm of overlapping sites of vulva
      • C51.9 - malignant neoplasm of vulva, unspecified
Epidemiology
Sites
Pathophysiology
  • Histogenesis uncertain
Clinical features
Diagnosis
Radiology description
Radiology images

Images hosted on other servers:
MRI, proximal type MRI, proximal type

MRI, proximal type

Ultrasound, proximal type with lung metastases

Ultrasound, proximal type with lung metastases

CT, proximal type with lung metastases CT, proximal type with lung metastases CT, proximal type with lung metastases

CT, proximal type with lung metastases


CT, proximal type with lung metastases

CT, proximal type with lung metastases

Prognostic factors
Case reports
Treatment
Clinical images

Images hosted on other servers:
Proximal type, preoperative

Proximal type, preoperative

Proximal type, intraoperative

Proximal type, intraoperative

Gross description
Gross images

Images hosted on other servers:
Proximal type, excision specimen

Proximal type,
excision specimen

Microscopic (histologic) description
  • In vulva: proximal type > distal type
  • Proximal type epithelioid sarcoma (Cancer 1983;52:1462, Am J Surg Pathol 1989;13:848, Am J Surg Pathol 1997;21:130, Mod Pathol 2001;14:655, Am J Surg Pathol 2015;39:836):
    • Extensively infiltrates surrounding tissues
    • Multinodular or diffuse growth pattern in collagenous or myxoid stroma
    • Atypical polygonal epithelioid cells
    • Minor spindle cell population may be present peripherally or admixed
    • Coarse vesicular chromatin and 1 - 2 prominent nucleoli
    • Abundant eosinophilic cytoplasm with distinct borders
    • Cytoplasm may contain an inclusion displacing nucleus peripherally (rhabdoid morphology)
    • Subset show exclusively rhabdoid morphology
    • Mitoses highly variable (2 - 57 mitoses per 10 high power fields) (Cancer 1983;52:1462)
    • Atypical mitoses, necrosis, hemorrhage and lymphovascular invasion common
  • Distal type epithelioid sarcoma of the vulva (Am J Surg Pathol 1989;13:848, Am J Surg Pathol 1997;21:130):
    • Pseudo granulomatous growth pattern: scattered small tumor nodules with central necrosis in a collagenous stroma with prominent lymphocytic inflammation
    • Monomorphic eosinophilic epithelioid or histiocytoid cells
    • Bland nuclei with inconspicuous nucleoli
    • Rhabdoid morphology not common
    • 8 mitoses per 10 high power fields in 1 vulvar case (Am J Surg Pathol 1989;13:848)
Microscopic (histologic) images

Contributed by David B. Chapel, M.D. and Priya Nagarajan, M.D., Ph.D.
Infiltrative growth

Infiltrative growth

Sheet-like growth

Sheet-like growth

Atypia

Atypia

Myxoid stroma

Myxoid stroma

High grade atypia

High grade atypia

Diffuse growth

Diffuse growth


Rhabdoid morphology

Rhabdoid morphology

Core biopsy

Core biopsy

Epithelioid cells

Epithelioid cells

Tumor necrosis

Cytokeratin

Virtual slides

Images hosted on other servers:
Proximal type, groin

Proximal type, groin

Proximal type, soft tissue

Proximal type, soft tissue

Proximal type, deep pelvic

Proximal type, deep pelvic

Distal type (classical)

Distal type (classical)

Cytology description
Electron microscopy description
Molecular / cytogenetics description
Molecular / cytogenetics images

Images hosted on other servers:
FISH and aCGH based detection of <i>SMARCB1</i> deletion FISH and aCGH based detection of <i>SMARCB1</i> deletion

FISH and aCGH based detection of SMARCB1 deletion

Videos

Proximal type epithelioid sarcoma of the groin

Sample pathology report
  • Vulva, mass, wide local excision:
    • Epithelioid sarcoma, proximal type (6.0 cm) (see comment)
    • Margins are negative for tumor
    • Comment: Microscopic examination reveals an infiltrative tumor composed of atypical epithelioid cells, some of which show prominent rhabdoid cytoplasmic inclusions. By immunohistochemistry, tumor cells are positive for cytokeratin AE1 / AE3, EMA and CD34 and show loss of SMARCB1 / INI1 expression. S100, CD31, ER and PR are negative. The findings are most consistent with proximal type epithelioid sarcoma. These are aggressive tumors with a high rate of local recurrence, lymph node metastasis and distant metastasis. Clinical and radiographic correlation are advised.
Differential diagnosis
Additional references
Board review style question #1

A 44 year old woman presented with a 3 cm painless vulvar mass. Her gynecologist diagnosed a Bartholin cyst and performed a conservative local excision. A representative photomicrograph of the lesion is shown. On immunohistochemical studies, tumor cells were positive for CK AE1 / AE3 and showed loss of INI1 staining. Which of the following is true about this tumor?

  1. CD34 is expressed in ~ 50%
  2. Exposure to ultraviolet radiation is the most common risk factor
  3. Fewer than 10% of patients experience local recurrence
  4. Hormone receptors (ER, PR) are usually positive
  5. Lymph node metastases are exceptionally rare
Board review style answer #1
A. CD34 is expressed in ~ 50%. This is a vulvar epithelioid sarcoma.

Comment Here

Reference: Epithelioid sarcoma
Board review style question #2

Which of the following molecular alterations is most commonly seen in proximal type epithelioid sarcoma?

  1. CDKN2A deletion
  2. DICER1 mutation
  3. SMARCA4 deletion
  4. SMARCB1 deletion
  5. TP53 loss of function mutation
Board review style answer #2
D. SMARCB1 deletion

Comment Here

Reference: Epithelioid sarcoma
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