Musculoskeletal Pathology Slides

KB 1

Osteomyelitis.  Involucrum surrounding sequestrum.

KB 2

Osteomyelitis.  Acute inflammatory infiltrate with bone necrosis.

KB 3

Osteoporosis.  X-ray of femur showing marked thinning of cortex and trabeculae.

KB 4

Rickets (metaphysis).  Groups of cartilage cells (chondrocytes) surrounded by osteoid.

KB 5

Paget's disease.  Osteolytic phase showing both osteoblastic and osteoclastic activity. Note mosaic pattern of bone and presence of intervening fibrovascular tissue.

KB 6

Paget's disease.  Sclerotic phase.  Thick bone with mosaic pattern.  No osteoclastic activity.

KB 7

X-ray of an osteoma in ethmoid sinus.

KB 8

Osteoma.  Broad irregular bony trabeculae with fibrous tissue within intervening spaces.

KB 9

X-ray of osteoid osteoma showing a small radiolucent focus (the nidus).

KB 10

Osteoid osteoma.  Tangled osteoid trabeculae, lined by osteoblasts, with intervening fibrovascular tissue.

KB 11

Osteoblastoma.  Similar appearance to osteoid osteoma (KB 10)

KB 12

Gross and x-ray of osteosarcoma showing metaphyseal intramedullary location with marked destruction of bone and spread to soft tissue.  Note presence of Codman's triangle.

KB 13

Osteosarcoma.  Osteoid arising from malignant mesenchymal cells.

KB 14

Osteosarcoma showing reactive bone formation.

KB 15

Osteosarcoma showing bone and cartilage formation.

KB 16

Osteosarcoma, poorly differentiated.  Note bizarre hyperchromatic tumour cells.  Multinucleated cells are also present.

KB 17

Osteochondroma, x-ray and gross.  Note bulbous head and slender pedicle with an outer cortex enclosing trabecular bone.

KB 18

Osteochondroma.  Note trabeculae of mature bone and an outer layer of cartilage.

KB 19

X-ray of enchondroma (phalanx) showing a well circumscribed lesion with expansion and deformity of the cortex.  Spotty calcification is present.

KB 20

Enchondroma showing cartilaginous tissue with a moderately cellular somewhat pleomorphic appearance.  However, the lesion is totally benign.

KB 21

Chondroblastoma.  Round to oval cells and prominent nuclei containing nucleoli.  Scattered giant cells are present.

KB 22

X-ray of chondrosarcoma.  Note lobulated appearance with definite destruction of cortex and spotty calcification.

KB 23

Chondrosarcoma, gray-white lobular cut surface with small areas of necrosis.

KB 24

Chondrosarcoma, well differentiated.  Moderate cellularity with mild to moderate pleomorphism.

KB 25

Chondrosarcoma, poorly differentiated.  Marked pleomorphism of tumour cells with some multinucleated forms.

KB 26

Ewing ' sarcoma.  Grey cut surface with small cysts and areas of hemorrhage and necrosis.

KB 27

X-ray of Ewing's sarcoma showing reactive new bone formation ('concentric onion skin layering').

KB 28

Ewing 's sarcoma.  Small round to oval cells with prominent nuclei and scant cytoplasm.

KB 29

X-ray and gross of giant cell tumour.  Epiphyseal location with marked thinning and erosion of cortex.  Cut surface is grey with areas of hemorrhage and necrosis.

KB 30

Giant cell tumour.  Giant cells containing many nuclei.  Background of pleomorphic spindle shaped cells.

KB 31

X-ray of osteosarcoma in lower femur (case 1).  Note soft tissue spread and Codman's triangle.

KB 32

Gross of osteosarcoma in lower femur (case 1).  Note intramedullary location.

KB 33

Osteosarcoma (case 1) showing pleomorphic hyperchromatic cells associated with bone formation.

KB 34

Well differentiated chondrosarcoma (case 2) showing mild cellularity and pleomorphism associated with myxoid change.  Myxoid change is not a feature of benign enchondroma.

KB 35

Higher power of KB 34 (case 2).

KB 36

Ewing 's sarcoma (case 3) showing sheets of small round to oval cells surrounding blood vessels.

KB 37

Ewing 's sarcoma (case 3) showing magenta PAS positivity for glycogen.

KB 38

Giant cell tumour in lower end of femur (case 4).  X-ray shows epiphyseal location of a lytic cystic lesion with little evidence of periosteal new bone formation.