Bone and joints Flashcards
fracture callus (vs neoplasm)
well circumscribed
zonation
well formed trabeculae
cartilage with enchondral ossification
osteoblastic rimming
no atypia
no mitoses
benign mimics of malignancy
fracture callus
AVN
osetomyelitis (acute and chronic)
synovial chondromatosis
BPOP
low grade chondrosarcoma (vs benign chondroid lesions)
PAGODA-6
painful, axial skeleton, rapid growth, old people,
bone destruction on radiology
atypia, mitoses, cellular, permeative
>6cm (or osteochondroma cap >2cm)
telangiectatic osteosarcoma vs ABC
markedly atypical cells in septa
(radiology and macro look the same!)
nodular joint lesions
PVNS
synovial chondromatosis
synovial lipomatosis
ABC associations
chondroblastoma
giant cell tumour
fibrous dysplasia
BUT also any other benign or malignant bone lesion!
giant cells
giant cell tumour
chondroblastoma
SBC and ABC
MFD
giant cell (reparative) granuloma (=solid ABC)
Brown tumour (hyperparathyroidism only distinguishes from GCG)
osteosarcoma
epithelioid/histiocytoid
LCH
mastocytoma
lymphoma
osteoid producing lesions
fracture callus
osteoid osteoma/osteoblastoma
ABC
osteosarcoma
osteosarcoma vs benign osteoid producing lesion
permeative
lace-like osteoid
no osteoblastic rimming
severe atypia
mitoses
mets in kids
neuroblastoma
rhabdomyosarcoma
retinoblastoma
mets in adults
5 B’s
bronchus
breast
bidney
byroid
brostate
(and melanoma)
OA vs RA
RA: joint destruction, inflamed synovium (hyperplasia, plasma cells and lymphocytes)
OA: reparative tissue, proliferative cartilage, bone sclerosis, osteophytes, less inflammation
gout vs pseudogout vs calcification
gout: needle shaped crystals, negative birefringence
pseudogout (calcium pyrophosphate): rhomboid shaped crystals, positive birefringence
‘calcification’ (usu soft tissues):
metastatic - disturbed calcium metabolism (eg Pagets, parathyroid)
dystrophic - dead tissue (eg coagulation necrosis, fat necrosis)
PVNS vs haemosiderotic and detritic synovitis
PVNS: mononuclear and giant cell proliferation
(both have pigment)
chondroblastoma vs GCT
CB: younger, sclerotic rim, S100+, chicken wire calcifications
adamantinoma vs osteofibrous dysplasia
OFD: single CK+ cells (cf nests in adamantinoma)
metaphyseal defect vs benign FH
same histology!
MFD: skeletally immature, metaphysis of long bones
if not in right age/location can call BFH
chondrosarcoma vs chordoma (esp at skull base)
chordoma: CK and brachyury+
giant cell reparative granuloma (features)
(=solid ABC)
on a spectrum between GCT and MFD
craniofacial bones, mainly jaw
small bones hand and feet
spine
ABC vs SBC
ABC: can deform bone, blood filled, fibrous septa with osteoid, fibroblasts and giant cells; may be USP6+
SBC: doesn’t deform bone, flat lining cells, serous fluid