Soft tissue

Smooth muscle



Topic Completed: 1 November 2012

Minor changes: 16 December 2020

Copyright: 2002-2021,, Inc.

PubMed Search: Leiomyoma[TI] general pathology

Vijay Shankar, M.D.
Page views in 2020: 4,494
Page views in 2021 to date: 4,948
Cite this page: Shankar V. Leiomyoma. website. Accessed October 15th, 2021.
Definition / general
  • Bland smooth muscle tumor without mitotic figures (eMedicine)
  • Not a WHO diagnosis (cutaneous and pilar tumors are described in the Skin volume)
  • Some tumors previously considered to be leiomyomas are actually GI stromal (GIST) tumors
  • See also colon-tumor, esophagus, uterus chapters
  • Skin and subcutis; also deep soft tissue, uterus (most common neoplasm in women)
  • Patients with multiple cutaneous leiomyomas may have autosomal dominant disorder (described under Cutaneous leiomyoma)
Case reports
Gross images

Images hosted on other servers:

Myxoid subcutaneous tumor

Microscopic (histologic) description
  • Bundles or fascicles of spindled cells with eosinophilic and possibly fibrillary cytoplasm
  • Nuclei are blunt ended and elongated with fine chromatin, indistinct nucleolus and variable cytoplasmic vacuole at one end
  • Minimal atypia
  • Few mitotic figures
  • No coagulative tumor necrosis
Microscopic (histologic) images

AFIP images

Oblong nuclei have rounded ends

Bundles of elongate
cells with eosinophilic
cytoplasm and oblong nuclei

Images hosted on other servers:

Calcified leiomyoma

Negative stains
Differential diagnosis
  • Angiomyolipoma: usually prominent vascular and lipomatous component
  • Leiomyosarcoma: more cellular, infiltrative, pleomorphic; mitotic activity and coagulative tumor cell necrosis
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