HistoPath of Bone Disease

Question 1

What are some examples of non-cancerous bone diseases ?

Answer 1

• osteoimperfecta
• rickets
• Pagets diseae
• osteoporosis

Question 2

What are some examples of bone cancer?

Answer 2

• osteosarcoma
• Ewings sarcoma
• Mutliple Myeloma
• Fibrosarcoma of bone

Question 3

Describe Osteogeneis Imperfecta

Answer 3

• Brittle Bone Disease
• hereditary disease affecting connective tissue
• caused by abnormal or reduced collagen production
• 4 types;
• Type 1 = most common
• Type 2 = very severe
• Type 3 & 4 = very severe

Question 4

Describe osteogenesis imperfecta type 1

Answer 4

• most common type
• sufferer will have no symptoms at birth but high incidence of fractures in childhood
• patient may also have hearing loss due to abnormality in inner ear bones

Question 5

Describe Osteogenesis Imperfecta Type 2

Answer 5

• Very severe
• presented at birth
• often resulting in stillborn or fractures during birth
• severe disability & very short lifespan –> often patient doesn’t survive till adulthood

Question 6

Describe Osteogenesis Imperfecta Type 3 & 4

Answer 6

• similar to type 1 with varying severity

Question 7

What are the histological characteristics of Osteoimperfecta

Answer 7

• severe forms lack an organised trabecular pattern
• crowded osteocytes within bone
• large areas of woven bone
• less severe forms still have crowded osteocytes with thin lamellar bones

Question 8

Describe Osteoporosis

Answer 8

• loss of bone mass
• often seen in post-menopausal women
• causes weakened bones more susceptible to injury

Question 9

Describe the histology of Osteoporosis

Answer 9

• trabecular or spongey part of bone is less dense in osteoporosis
• pores in trabeculae are larger & pore walls thinner
• thinning of cortical bone
• increased osteoclast activity
• decreased osteoblast activity

Question 10

Describe Rickets

Answer 10

• observed in children
• softening of bones which culminates in abnormal bone growth & caused by vitamin D deficiency
• deficient mineralisation at growth plate of long bones = results in stunted growth
• if not treated bone deformity occurs, typically causing bowed legs & thickening of long bones

Question 11

Describe the histology of Rickets

Answer 11

• loss of columnar arrangement of chondrocytes
• tongue-like projections of cartilage extending into the spongiosa
• thickening & disorganisation of hypertrophic zone

Question 12

Describe Paget Disease

Answer 12

• effects people who are middle aged/ European
• considered a metabolic bone disease
• can effect a single bone or many
• manifests itself as excessive bone resorption - performed by osteoclasts & excessive production
• leads to weak deformed bones

Question 13

Describe the Histology of Pagets Disease

Answer 13

• presence of large multinucleate osteoclasts
• 10x more osteoclasts present in diseased bone
• indistinct haversian systems
• structure of cortical bone weakened but mass is increased

Question 14

Describe Osteoarthritis

Answer 14

• characterised by breakdown of cartilage in joint
• symptoms experienced by patient involve pain, stiffness & bone grating
• graded by the Kellgren-Lawrencescale 1= mild 4 = severe

Question 15

Describe the Histology of Osteoarthritis

Answer 15

• increasing thickness of bone plate can be clearly seen
• roughness of subchondral plate
• trabecular bone structure seems to become disorientated

Question 16

Describe Rheumatoid Arthritis

Answer 16

• chronic inflammatory disease
• effects the joints, skin, eyes, heart & kindeys
• risk factors = age, genetic disposition, gender & environmental exposure
• bone & cartilage can be destroyed in the joints, along with weakened tendons & ligaments

Question 17

Describe the histology of Rheumatoid Nodules

Answer 17

• main histological feature = abundance of macrophages
• high number of fibroblasts
• expresses inflammatory cytokines–>tumour necrosis factor alpha & interferon gamma

Question 18

Describe Osteosarcoma

Answer 18

• occurs in the long bones
• craniofacial osteosarcoma make up 6-7% of all osteosarcomas
• high grade tumour of bone in which tumour cells cna produce osteoid

Question 19

Define Osteoid

Answer 19

mineralised tissue

Question 20

Describe Ewings Sarcoma

Answer 20

• primarily a cancer of bone or soft tissue
• mainly found in hip bones, ribs & long bones
• can also metastasize to other areas
• diagnosis is made with a biopsy showing sheets of small round blue cells with prominent nuclei & minimal cytoplasm
• mostly occurs in young people - more common in men

Question 21

Describe Fibrosarcoma of Bones

Answer 21

• rare tumour - mainly of the long bones
• very aggressive form with poor prognosis
• spindle cells present in herringbone pattern
• treatment is usually wide surgical resection & multiagent chemo

Question 22

Describe Multiple Myeloma

Answer 22

• cancer of the bone marrow
• influences production of RBCs
• can effect spine, skull, pelvis & ribs
• myeloma doesn’t cause lump/tumour instead it damages the bones & affects production of healthy blood cell
• more common in ; men, adults over 60, black people & people with family history

Question 23

How is multiple myeloma diagnosed ?

Answer 23

• made with a bone marrow biopsy showing monoclonal plasma cells > 10%