Pleura & peritoneum
Pleura mesothelial tumors
Mesothelioma-sarcomatoid
Author: Vaidehi Avadhani, M.D.
Last author update: 1 November 2013
Last staff update: 24 August 2023
Copyright: 2003-2024, PathologyOutlines.com, Inc.
PubMed Search: Sarcomatoid mesothelioma pleura
See Also: Mesothelioma
Table of Contents
Definition / general | Epidemiology | Radiology images | Case reports | Treatment | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Positive stains | Negative stains | Electron microscopy description | Differential diagnosis | Additional referencesCite this page: Avadhani V. Mesothelioma-sarcomatoid. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/pleuramesotheliomasarcomatoid.html. Accessed April 20th, 2024.
Definition / general
- Defined as > 90% spindle shaped tumor cells
- Termed desmoplastic if > 50% of the tumor shows desmoplastic pattern
Epidemiology
- 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
- 61 year old woman with shortness of breath (Intern Med 2013;52:249)
- Osteoblastic variant (Br J Radiol 2011;84:e106)
Treatment
- Sarcomatoid histology (pure or mixed) is poor prognostic factors after extrapleural pneumonectomy
- Chemotherapy is recommended according to NCCN guidelines (National Comprehensive Cancer Network: NCNN Guidelines for Treatment of Cancer by Site [Accessed 23 March 2018])
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
- Keratin: pancytokeratin positive in > 70%; use multiple antibodies (AE1 / AE3, CAM 5.2 and CK7); if only focal cytokeratin staining is present, stain additional blocks with vimentin to check tissue antigen integrity
- D2-40, calretinin
- GLUT1: overall sensitivity and specificity in mesothelioma is 53% and 98% respectively (Arch Pathol Lab Med 2012;136:804)
Negative stains
Electron microscopy description
- No specific ultrastructural features
Differential diagnosis
- Other biphasic tumors:
- Desmoid tumor
- Fibrous pleuritis
- Sarcoma
- Sarcomatoid carcinoma:
- Kidney may be difficult to differentiate
- Lung
- Solitary fibrous tumor: CD34+, BCL2+, CD99+, keratin-
Additional references
