Pleura & peritoneum

Pleura mesothelial tumors


Last author update: 1 November 2013
Last staff update: 24 August 2023

Copyright: 2003-2023,, Inc.

PubMed Search: Sarcomatoid mesothelioma pleura

See Also: Mesothelioma

Vaidehi Avadhani, M.D.
Page views in 2022: 4,616
Page views in 2023 to date: 3,988
Cite this page: Avadhani V. Mesothelioma-sarcomatoid. website. Accessed September 30th, 2023.
Definition / general
  • Defined as > 90% spindle shaped tumor cells
  • Termed desmoplastic if > 50% of the tumor shows desmoplastic pattern
  • 10 - 20% of all mesotheliomas
Radiology images

Images hosted on other servers:

Small left pleural effusion

Clumped calcification and pleural effusion

Coarse, clumped calcification

Case reports
Microscopic (histologic) description
  • Conventional, spindle cell type: spindle cells arranged in fascicles or having a haphazard distribution
  • Desmoplastic variant
  • Heterologous differentiation: osteosarcoma, chondrosarcoma or other sarcoma-like areas
  • Lymphohistiocytoid: diffuse large histiocyte-like cells with dense infiltrate of lymphocytes and plasma cells; behaves similar to epithelioid type, some prefer classifying as such (Am J Surg Pathol 2007;31:711)
Microscopic (histologic) images

Images hosted on other servers:

Infiltrative spindle cells

Various images

AE1 / AE3, CAM 5.2, calretinin

WT1, D2-40

Cytology description
  • Tumor cells not shed in pleural fluid, which typically contains only reactive mesothelial cells
Positive stains
Negative stains
  • CD31 (positive in angiosarcoma), CD34 (solitary fibrous tumor), S100 (neurogenic tumors but mesotheliomas may show focal staining)
  • CD45
  • May have focal positive muscle markers
Electron microscopy description
  • No specific ultrastructural features
Differential diagnosis
Additional references
Back to top
Image 01 Image 02