Pathology Flashcards
What pathological findings are seen in the acute phases of rheumatoid arthritis?
Pannus formation (inflammatory granulation tissue formed at edges of articular surfaces).
Hyperplastic/reactive synovium.
Cartilage is destroyed by inflammatory process which is seen as a loss of joint space.
What pathological findings are seen in the chronic phase of rheumatoid arthritis?
Fibrosis.
Deformity.
What pathological findings are commonly seen in chronic inflammation of inflammatory arthritides?
Evidence of lymphocyte and plasma cell infiltration in histological samples.
What pathological findings are commonly seen in acute inflammation of inflammatory arthritides?
Evidence of oedema, fibrin and reactive features in synovial cells.
What cytological findings would confirm a diagnosis of gout?
Joint fluid examined under cross-polarised light to detect needle-shaped crystals.
What histological findings would confirm a diagnosis of gout?
Amorphous eosinophilic debris and inflammation (giant cells).
Crystals are lost through the processing of tissue to see this.
What cytological findings would confirm a diagnosis of pseudogout?
Fresh microscopy shows weak positive birefringence of rhomboid-shaped crystals that are thicker and bigger than needle-shaped urate crystals.
What are three stages of Paget’s disease?
Osteolytic.
Mixed.
Burnt out.
Net result is thick excess bone with abnormal reversal lines (mosaic pattern).
Which bones does Paget’s disease tend to affect?
Usually axial bones.
Small bones less commonly affected.
What are the causes of pain in Paget’s disease?
Microfracture.
Nerve compression.
What enlargements and abnormal shapes of bone occur in Paget’s disease?
Leontiasis ossea (new hats).
Platybasia (skull base abnormality).
Sabre tibia.
What secondary malignancy can occur in Paget’s disease?
Osteosarcoma.
What initially occurs after a fracture in the bone tissue?
Haematoma –> fibrin mesh.
Influx of inflammatory cells.
Cytokine release – recruitment of osteoprogenitor cells from periosteum and medullary cavity.
After 1 week – callus, organised haematoma, early recruitment and remodelling at ends of bone.
What happens 2-3 weeks are a fracture in the bone tissue?
Maximum girth of callus.
Woven bone deposited perpendicular to cortical bone.
Some cartilage deposition at fracture site which undergoes endochondral ossification.
Bridging with a bony callus.
What is remodelling of bone?
Woven bone in callus is constantly remodelled.
Areas that are under less stress are resorbed and eventually the bone returns to its normal shape.
What could be an underlying cause of a pathological fracture?
Osteoporosis.
Tumours (benign [children; primary tumour]; malignant [adults; metastatic]).
What cancers tend to metastasise to bone?
Breast
Bronchus
Prostate
Thyroid
Kidney
Big Boys Pee Through Kidneys
What joint changes occur in osteoarthritis?
Cortical bone thickens to cope with load.
Fractures.
Leaks synovial fluid through bone forming small cysts.
Rapid remodelling of bone to cope with stress.
Remodelling is disorganised and produces abnormal outgrowths (osteophytes).
What is the pathology behind radiological findings of osteoarthritis?
Loss of joint space = cartilage loss.
Subchondral sclerosis = eburnation.
Subchondral cysts = synovial fluid accumulation.
Osteophytes = disorganised bone remodelling.
What are common benign MSK lesions?
Ganglion cyst.
Giant cell tumour.
Fibromatosis.
Fibrous cortical defect - rarer.
Fibrous dysplasia.
What is a ganglion cyst?
Peripheral lump near a joint capsule of tendon sheath.
Common around wrist.
Degenerative change within connective tissue.
Not a true cyst - no epithelial lining.
Histologically, what is seen in a ganglion cyst?
Space with myxoid material.
Secondary inflammatory changes.
What is a leiomyoma?
Benign tumour of the smooth muscle.
What is a leiomyosarcoma?
Malignant tumour of the smooth muscle.
What is a rhabdomyoma?
Benign tumour of the skeletal muscle.
What is a rhabdomyosarcoma?
Malignant tumour of the skeletal muscle.
What is an enchondroma?
Benign lesion of the cartilage.
What is an osteoma?
Benign tumour of the bone.
What is an osteoid osteoma?
Benign tumour that arises from osteoblasts.
What is an osteosarcoma?
Malignant tumour of the long bones.
What are the histological appearances of nodular fasciitis?
Very chaotic appearance.
Haemorrhage.
Pseudocystic spaces.
Large atypical cells.
Frequent mitoses.
Normal mitoses.
