Mesenchymal chondrosarcoma
Mesenchymal chondrosarcoma is a rare type of chondrosarcoma that is found in the soft tissue.
General
- Rare variant of chondrosarcoma.
- 2–10% of primary chondrosarcomas.
- Adolescents and young adults.
- Female predilection.
- Most commonly intraosseous but can occur in extraskeletal sites especially the central nervous system (from the meninges).
- The mesenchymal in the name refers to the ability to arise in soft tissues.[1]
- Conceptualized as originating from a pleuripotential mesenchymal cell with foci recapitulating enchondral ossification.
- The small cells appear to be an undifferentiated cartilage stem cell which “differentiate” into benign cartilage.[2]
Gross
Pink and fleshy with foci of calcification.
Microscopic
Features:
- Malignant tumour with a characteristic biphasic pattern.
- Cellular poorly differentiated small round blue cells.
- Islands of well-differentiated hyaline cartilage.
- Progressive maturation of cartilage towards the center.
- Central calcification or bone formation.
- Can have a hemangiopericytomatous vascular pattern.
Notes:
- May be described as white clouds in a dark blue sky.
DDX
- Hemangiopericytoma - no cartilage.
- Lymphoma - Sox9 negative, CD45 positive.
- Metaplastic glioblastoma - usually older adults - GFAP positive.
- Chondrosarcoma (NOS) - usually older adults - hyaline cartilage is malignant.
- Small cell osteosarcoma - Sox10 negative, no cartilage.
- Ewing sarcoma - both are CD99 positive but ES is Sox9 negative, no cartilage.
- Monophasic synovial sarcoma - also can have the hemangiopericytomatous vasculature.
Note:
- Depends a bit on where the tumour is located and how much cartilage is readily visible.
Images
Islands of cartilage in a background of small blue cells.(SKB)
Islands of cartilage in a background of small blue cells.(SKB)
Islands of cartilage in a background of small blue cells.(SKB)
Islands of cartilage in a background of small blue cells.(SKB)
Islands of cartilage in a background of small blue cells.(SKB)
Islands of cartilage in a background of small blue cells.(SKB)
Small blue cells predominate.(SKB)
www:
- Mesenchymal chondrosarcoma (ouhsc.edu).
- Pathology Outlines - Hemangiopericytomatous example [1]
- Sarcoma Images - [2]
- CNS Atlas - [3]
- CNS Atlas - [4]
- CNS Atlas - [5]
![[1]](http://pathologyoutlines.com/wick/chondrosarcoma%20mesenchymal%20type%20micro0007.jpg){kind=link}
![[3]](http://www.cnsatlas.com/medicalatlas/images/370/800_poIB6FYZQ73wh.jpg){kind=link}
![[4]](http://www.cnsatlas.com/medicalatlas/images/370/800_9oJtTQXXxaEB3.jpg){kind=link}
![[5]](http://www.cnsatlas.com/medicalatlas/images/370/800_8h2C7upeOj3EB.jpg){kind=link}
IHC
- SOX9 (positive in small cells and chondrocytes).[3]
- S100 (positive in chondrocytes not in small cells).
- Osteocalcin (negative in small cells).
- CD99 - (positive in small cells)
Molecular
t(8;8)(q21.1;q13.3) HEY1-NCOA2.[4]
See also
References
- ↑ Dowling EA (June 1964). "Mesenchymal chondrosarcoma". J Bone Joint Surg Am 46: 747–54. PMID 14161087. http://www.ejbjs.org/cgi/reprint/46/4/747.pdf.
- ↑ Fanburg-Smith, JC.; Auerbach, A.; Marwaha, JS.; Wang, Z.; Rushing, EJ. (May 2010). "Reappraisal of mesenchymal chondrosarcoma: novel morphologic observations of the hyaline cartilage and endochondral ossification and beta-catenin, Sox9, and osteocalcin immunostaining of 22 cases.". Hum Pathol 41 (5): 653-62. doi:10.1016/j.humpath.2009.11.006. PMID 20138330.
- ↑ Pang, ZG.; He, XZ.; Wu, LY.; Wei, W.; Liu, XY.; Liao, DY.; Li, FY.; Zhang, XL. (Jun 2011). "[Clinicopathologic and immunohistochemical study of 23 cases of mesenchymal chondrosarcoma].". Zhonghua Bing Li Xue Za Zhi 40 (6): 368-72. PMID 21914343.
- ↑ Panagopoulos, I.; Gorunova, L.; Bjerkehagen, B.; Boye, K.; Heim, S. (Jul 2014). "Chromosome aberrations and HEY1-NCOA2 fusion gene in a mesenchymal chondrosarcoma.". Oncol Rep 32 (1): 40-4. doi:10.3892/or.2014.3180. PMID 24839999.