Bone, cartilage, joint pathology Flashcards
Knee joint.
Dx?
Key features?
XR features?
Synovial chondromatosis
Features: Synovial chondromatosis has a well-defined, multinodular architecture, characterized by discrete nodules of hyaline cartilage within subsynovial tissue. The chondrocytes are arranged in small clusters. Matrix usu hyaline but can be myxoid. Can undergo endochondral ossification.
XR: periarticular punctate calcifications
Erdheim Chester disease
What is it?
Common genetic mutation
Key histo features
IHC
Rare, clonal histiocytosis with frequent multiorgan involvement
Also known as polyostotic sclerosing histiocytosis
Skeletal involvement in almost all (> 95%) cases, most often in the long bones of the lower extremities
Correlation of clinical features, histology and radiological findings are essential for diagnosis (Blood 2016;127:2672)
Systemic disease with frequent involvement of bone, retroperitoneum (hairy kidney, coated aorta), CNS and lung
BRAF V600E mutation in > 50% of cases
Soft tissue infiltrate of bland appearing histiocytes characterized by abundant foamy (xanthomatous) cytoplasm with surrounding fibrosis
Touton giant cells are frequently present
Associated lymphoplasmacytic infiltrate is sparse
Erdheim-Chester disease may be a component of mixed histiocytosis with Langerhans cell histiocytosis or Rosai-Dorfman disease
osteoid osteoma vs osteoblastoma
distinguishing clinical and radiological features?
gene rearrangements in osteoid ostoma and osteoblastoma
FOS (and less so FOS-B) gene rearrangements.
FOS gene rearrangements also found in epithelioid haemangioms
osteosarcoma
RF for primary vs secondary osteosarcoma
Anatomically, how can osteosarcoma be described and which are high vs low grade
hereditary condition a/w multiple osteochondromas?
Mode of inheritance?
Multiple hereditary exostosis.
Autosomal dominant.
multiple endchondromas, syndromic association?
Ollier’s syndrome (not inherited)
