Type II collagen, but not aggrecan expression, distinguishes clear cell chondrosarcoma and chondroblastoma.
OBJECTIVE
Chondroblastoma and clear cell chondrosarcoma are uncommon skeletal neoplasms that have a strong tendency to involve the epiphysis of long bones. They also share some overlapping histological features. Thus, it can be difficult both radiographically and histologically to distinguish these neoplasms. So far there are no immunohistochemical markers available that have been shown to be helpful in differentiating these neoplasms.


METHODS
In our study of a series of clear cell chondrosarcomas (n = 15) and chondroblastomas (n = 35), S100, vimentin, aggrecan and collagen type II were detected by immunohistochemistry.


RESULTS
We detected immunohistochemical evidence of type II collagen within both the extracellular matrix-rich (chondroid) and matrix-poor areas in all 15 cases of clear cell chondrosarcoma. In contrast, immunohistochemical analysis failed to show staining of collagen type II in any of the 35 chondroblastomas. Other markers, including S100 protein, vimentin and aggrecan proteoglycan were tested in parallel and found to be focally positive in both neoplasms.


CONCLUSIONS
Therefore, our data show that in cases when clear cell chondrosarcoma and chondroblastoma pose a diagnostic challenge, the presence of type II collagen in the extracellular tumour matrix significantly supports the diagnosis of clear cell chondrosarcoma and aids in distinguishing it from chondroblastoma.
Department of Pathology, University of Leipzig, Leipzig, FRG.
S
S
Söder
A M
AM
Oliveira
C Y
CY
Inwards
S
S
Müller
T
T
Aigner
D053674:Aggrecans; D014408:Biomarkers, Tumor / Q000032:analysis; D001859:Bone Neoplasms / Q000737:chemistry* / Q000175:diagnosis / Q000473:pathology*; D002804:Chondroblastoma / Q000737:chemistry* / Q000175:diagnosis / Q000473:pathology*; D011508:Chondroitin Sulfate Proteoglycans / Q000032:analysis*; D002813:Chondrosarcoma / Q000737:chemistry* / Q000175:diagnosis / Q000473:pathology*; D024043:Collagen Type II / Q000032:analysis*; D003937:Diagnosis, Differential; D005109:Extracellular Matrix / Q000737:chemistry / Q000473:pathology; D016326:Extracellular Matrix Proteins / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D037181:Lectins, C-Type / Q000032:analysis*; D009418:S100 Proteins / Q000032:analysis; D012680:Sensitivity and Specificity; D014746:Vimentin / Q000032:analysis
D053674:Aggrecans; D014408:Biomarkers, Tumor; D011508:Chondroitin Sulfate Proteoglycans; D024043:Collagen Type II; D016326:Extracellular Matrix Proteins; D037181:Lectins, C-Type; D009418:S100 Proteins; D014746:Vimentin