Other tumors


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Last staff update: 24 February 2021

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PubMed Search: leiomyosarcoma[title] stomach review[ptyp]

Raul S. Gonzalez, M.D.
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Cite this page: Gonzalez RS. Leiomyosarcoma. website. Accessed May 19th, 2024.
Definition / general
  • Malignant smooth muscle sarcoma that arises from the muscularis propria of the stomach
  • Accounts for 1% of all malignant tumors of the stomach
Essential features
  • Rare malignant neoplasm with atypia, mitoses and necrosis histologically
  • Positive for SMA and desmin
  • Intermediate to poor prognosis
Clinical features
Prognostic factors
Case reports
  • 50 year old woman with hypertension and diabetes presented with a submucosal gastric mass (Case #438)
Gross images

Images hosted on other servers:

Large gastric leiomyosarcoma (> 8 cm)

Microscopic (histologic) description
Microscopic (histologic) images

Contributed by Raul S. Gonzalez, M.D.


Case #438






Positive stains
Negative stains
Sample pathology report
  • Stomach, antrum, resection:
    • Leiomyosarcoma (6.4 cm) (see comment)
    • Margins of resection unremarkable.
    • Two benign lymph nodes.
    • Comment: The tumor shows prominent nuclear atypia, numerous mitotic figures and regions of necrosis. Immunohistochemical stains for SMA and desmin are positive in the tumor. Leiomyosarcomas are rare in the stomach and risk factors for progression in this location remain poorly defined.
Differential diagnosis
Board review style question #1
Which of the following is a poor prognostic indicator for leiomyosarcoma of the stomach?

  1. Greater than 20 mitoses per 10 high power fields
  2. Ki67 proliferative index above 50%
  3. Size greater than 5 cm
  4. Tumor necrosis
Board review style answer #1
C. Size greater than 5 cm

Comment Here

Reference: Leiomyosarcoma
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