- Discussion:
- shows characteristic "cobblestone" pattern;
- areas of round, plump chondroblasts (stones), enmeshed in chondroid matrix;
- nodular areas of a chondroid tissue are prominent;
- cartilagenous matrix may have small foci of calcification between between
chondroblasts (chicken wire calcification) around islands of cartilage;
- calcification helps to separate chondroblastoma from giant cell tumor;
-
cytoplasm: may be pale, and may have an octagonal shape due to abutman against other tumor cells;
-
nuclei: are homogenous & oval & contain groove,
which resembles
EOG;
-
secondary Aneurysmal bone cyst
- about 17% of chondroblastomas show features c/w
ABC;
- may result in grossly hemorrhagic or cystic specimen;
-
clumps of giant cells are found adjacent to areas of spindle cell stroma;
- demonstrates positive S-100 reactivity;
- Diff Dx:
-
tuberculosis:
- can cause lytic defects in epiphyseal bone;
- rheumatoid synovitis
-
pigmented villonodular synovitis:
-
chondrosarcoma:
- may confused w/ chondrosarcoma due to pleomorphic cellular pattern,
mitotic figures & multinucleated giant cells between chondroid areas;
