Other tumors
Smooth muscle tumor

Author: Nat Pernick, M.D. (see Authors page)

Revised: 27 March 2018, last major update December 2013

Copyright: (c) 2003-2018,, Inc.

PubMed Search: Smooth muscle tumor pleura

Cite this page: Pernick, N. Smooth muscle tumor. website. Accessed August 16th, 2018.
Definition / general
  • Extremely rare, < 10 cases reported
  • Case report in 32 year old white man of tumor with malignant behavior (Arch Pathol Lab Med 2000;124:1688)
  • Low but definite malignant potential
Gross description
  • Well circumscribed, encapsulated, pink and shiny cut surface with fibrous streaks and yellow calcifications
Microscopic (histologic) description
  • Proliferation of bland spindle cells with elongated nuclei, eosinophilic cytoplasm
  • Rare mitotic figures, focal areas of increased cellularity and atypia
  • Scattered calcifications
Positive stains
Negative stains
Electron microscopy description
  • Discohesive spindle cells with elongated nuclei
  • Parallel arrays of intracytoplasmic actin microfilaments
  • No microvilli, tonofilaments or desmosomes