Path 2.2

Question 1

normal WBC/PMN

Answer 1

WBC: <200
PMN: <25%

Question 2

inflammation WBC/PMN

Answer 2

WBC: 5,000-75,000
PMN: >50%

Question 3

bacterial infection WBC/PMN

Answer 3

WBC: >50,000-100,000
PMN: >70%

Question 4

ganglion cyst

Answer 4

unlined (no synovium).
fluid filled lesion near joint capsule.
due to degeneration of periarticular soft tissue

Question 5

RA

Answer 5

autoimmune.
T cell mediated.
Destruction of cartilage, ankylosis of joints, pannus formation.
HLA-DR4.

Synovial cysts

Question 6

avascular necrosis is associated with (causes)

Answer 6

Use of glucocorticoids, excess alcohol.
Men: alcohol
Women: lupus

Question 7

gout

Answer 7

Monosodium urate crystals.
Tophi formation: aggregations of crystals surrounded by macrophages, lymphocytes, giant cells.
Yellow needles.
90% due to overproduction/underexcretion of uric acid

Question 8

psuedogout

Answer 8

Calcium pyrophosphate.

Rhomboid, blue.

Question 9

Chondrosarcoma

Answer 9

Cartilage.
Malignant.
Middle age+
Pelvis, central skeleton.
Large lesions, small/irregular nuclei, abnormal mitoses

Question 10

Osteoid Osteoma

Answer 10

Bone
Benign.
Adults 20-40.
Bones formed by endochondral ossification.
Woven bone, central nidus, sclerotic rim

Question 11

Osteosarcoma

Answer 11

most common primary malignancy in bone
Bone.
Malignant.
Under 20, elderly (Rb mutation, Paget’s).
Knee, shaft of long bones.
CODMANS TRIANGLE (tent of radiolucency), painful enlarging mass, abnormal mitoses

Question 12

Ewing Sarcoma

Answer 12

Bone.
Malignant.
teens-20s.
Femur, long bones.
ONION SKIN, small round blue cells

Question 13

Giant cell tumor

Answer 13

Bone. 
Benign.
Adults >20.
Long bone, knee.
Soap bubble, osteoclast giant cells, soft tissue mass, hemorrhagic