In cytology, osteoblasts look very similar to what, everything but the chromatin pattern?
Cartilage-capped bony protrusion that arise from the surface of any bone that models or grows by endochondral ossification.
What is the general thought behind why an osteochondroma occurs and what's the treatment?
Prob with cartilage at the epiphyseal plate; it gets moved and bone still forms under by endochondral ossification in a stalk of the bone; leave it alone!
What are the 2 kinds of chondromas?
Enchondroma and periosteal chondroma
What is the architecture of enchondromas? What bony structure do they grow in? What is the most common site? How do they show up on XR?
Lobulated; medullary cavity; small bones of hands/feet; radiolucent areas with little opacities (popcorn) from calcification
What is the difference between Ollier's disease and Mafucci's syndrome?
Ollier's is multiple enchondromas all over and Mafucci's is multiple enchondromas and also soft tissue angiomas
What is a major difference in telling a periosteal chondroma from osteochondroma?
In osteochondroma, there is a hole in the cortex (like the stalk is continuous); in periosteal chondroma the chondroma grows on the outside of the cortex (so cortex is not really disrupted)
What stain stains neoplastic chondroblasts in chondroblastoma? Where is the location of the tumor? What is unique about the calcification?
S100; epiphysis of long bones; "chicken-wire" calcification
Lobular aggregates of spindle-shaped to stellate cells arranged within a chondroid to myxoid matrix. Lobules are surrounded by cellular areas. What is the tumor and the location on bone it affects?
Chondromyxoid fibroma; metaphysis
Which bones most commonly get chondrosarcoma? In addition to NOS, what are 3 other subtypes?
Flat bones of axial skeleton like pelvis, scapula, and sternum; dediff, myxoid, clear cell
What criteria determine the grade of chondrosarcoma?
Cellularity, atypia, amd mitoses
What histologically separates a low-grade chondrosarcoma from enchondroma?
Chondrosarc permeates between existing trabeculae
What does a dediff chondrosarc look like?
There is a regular well-diff chondrosarc, but also a distinct high-grade sarcomatous area
How do you tell a dediff chondrosarc from a chondroblastic osteosarc?
In dediff the dedif part is sharply outlined from the well-diff chondrosarc (like holes in swiss cheese); in chondroblastic osteosarcoma, the parts intermix
What does a mesenchymal chodnrosarc look like? What's the clinical course?
Biphasic pattern: islands of hyaline cartilage mixed in what looks like an HPC; aggressive clinical course
What does a clear cell chondrosarc look like?
Well-diff chondrosarc, but also abundant large round clear cells with well-defined cell borders (look like bubbles almost)