Bone lesions, diseases, and arthropathies; questions.

mwhyett's version from 2017-05-17 17:56

Section 1- Classification

Question Answer
What is a bone tumour?An abnormal bony growth.
Give two examples of metastatic bone lesions;Osteosarcoma, and chondrosarcoma.
Give two examples of benign bone lesions;Osteoma, and aneurysmal bone cysts.
What is the definition of a metastatic tumour?When a malignant tumour spreads to another site.
What is the type of tumour that becomes malignant but is initially benign?Secondary tumour.
What 6 things does the classification of bone tumours depend on?1. Age. 2. Number of lesions. 3. Site of the lesion/s. 4. Bone destruction. 5. Periosteal reaction. 6. Borders of the lesion.
What is the general presentation of a benign process?Uniform destruction with a sharply defined border.
What is the general presentation of a most likely malignant process?Patchy areas of destruction with ragged borders.
What is the general presentation of an aggressive malignant process?Permeative, ill defined area spreading through marrow space.
What types of tumours have a narrow zone of transition?Benign .
What types of tumours have a wide zone of transition?Malignant.
What is the zone of transition?The border between the lesion and the normal bone.
Where is an eccentric lesion located?Off centre.
What is an expansile lesion?A lesion that does not stay within the confines of the original bone.
What type of lesion is most likely to grow beyond the periosteum?Malignant
Why does a periosteal reaction occur?Because the periosteum is irritated either by trauma, tumour, or infection.
What is the most benign form of periosteal reaction?Callus formation.
How does the rate of growth of the lesion impact the periosteal reaction?If the process is slow growing, the periosteum can produce new bone at the same rate of growth as the lesion. If the process is growing rapidly, the periosteum cannot maintain the same rate of growth.
What sort of periosteal reaction does a slow growing lesion have?A solid, uninterrupted bony margin.
What sort of periosteal reaction does a fast growing lesion have?An interrupted bony pattern.
What does an onion skin periosteal reaction indicate about the lesion growth?That the lesion has an irregular rate of growth.
What does a sunburst periosteal reaction indicate about the lesion growth?That the lesion has a rapid and steady rate of growth.
What causes a sunburst periosteal reaction?A rapid growth rate, meaning the fibres that connect the periosteum to the bone become stretched and ossify.
What sort of a lesion does a Codman triangle indicate?An extremely aggressive lesion.
How does a Codman triangle form?When the lesion grows far quicker than the periosteum can, so only the edge of the raised periosteum can ossify.
Give four examples in which you could see a Codman triangle;1. Osteosarcoma. 2. Ewing sarcoma. 3. Giant cell tumour. 4. Osteomyelitis.

Section 2- Bone Lesions

Question Answer
Where are simple bone cysts usually found?The metaphysis of the proximal femur or humerus.
Which patient demographic do simple bone cysts normally occur?In males under 20 years old.
What do simple bone cysts contain?Clear serous fluid.
Are simple bone cysts malignant or benign?Benign.
What is the appearance of a simple bone cyst?Lucent bone expansion, with fibrous septa, and a thin sclerotic rim.
How many simple bone cysts lead to fractures?50%.
Where do aneurysmal bone cysts occur?Within the long bones (most common) and vertebrae.
Which patient demographic do aneurysmal bone cysts normally occur?In females aged between 10-30 years old.
How do aneurysmal bone cysts form?
Name two initiating factors for aneurysmal bone cysts;1. Trauma. 2. Arteriovenous fistulae.
What is the best modality for imaging aneurysmal bone cysts in the appendicular skeleton?Plain film
What is the best modality for imaging aneurysmal bone cysts in the axial skeleton?CT
What are aneurysmal bone cysts filled with?Blood
What is the process in which aneurysmal bone cysts form?It rapidly grows and expands, then stabilises and ossifies to form a bony shell and septae, giving trabeculated appearance.
What type of cyst is a characteristic feature of OA?Subchondral cysts
What is a subchondral cyst?A cyst that occurs close to a joint.
What sort of appearance does a subchondral cyst have?A lytic appearance.
What do subchondral cysts contain?Synovial fluid.
What causes subchondral cysts to form?Pressure or stress on articular cartilage and subchondral bone leads to the leakage of synovial fluid leaking through into the bone.
What periosteal reaction is mostly seen in paediatric Ewings sarcoma?Sunburst reaction
Where is Ewings sarcoma usually found?Pelvis, femora, humeri, and ribs.
In which patient demographic does Ewings sarcoma occur?Young males, (peak at age 13).
What is Ewings sarcoma?A malignant round cell tumour.
What is a common serological indication of Ewings sarcoma?An elevated erythrocyte sedimentation rate.
How do patients with Ewings sarcoma usually present?Non-specific symptoms and localised pain.
What part of the bone does Ewings sarcoma usually affect?The diaphysis.
What is the most common type of periosteal reaction in Ewings sarcoma?Lamellated onion skin periosteal reaction.
What zone of transition does Ewings sarcoma have?A wide zone
Which modality best shows Ewings sarcoma?MRI, as the bone and soft tissue can be fully demonstrated.
What is osteosarcoma?A malignant bone forming tumour.
What percentage of primary bone malignancies does osteosarcoma account for?20%
Which part of the bone is most commonly affected in osteosarcoma?The metaphysis.
Which part of the body is most commonly affected by osteosarcoma?Tubular long bones, typically the knee.
Which bone cell does osteosarcoma affect?Osteoblasts.
Does osteosarcoma have a narrow or wide zone of transition?Wide
What types of periosteal reactions are commonly seen with osteosarcoma?Sunburst reaction and Codman triangle.
What type/s of bone destruction is seen in osteosarcoma?Medullary and cortical bone destruction.
What is myeloma?Cancer of the white blood cells that are produced in the bone marrow.
Which patient demographic is most affected by myeloma?Males over the age of 50.
Which 4 sites are the most common sites for myeloma?Axial skeleton, pelvis, proximal femora, and humeri.
How is myeloma diagnosed?By a bone biopsy.
What is common with myeloma?Vertebral collapse, and osteopenia.
What is a key characteristic of multiple myeloma?Well defined, punched out lesions in the skull.
What is multiple myeloma in the skull referred to as?Pepper pot skull.
Which modality if most sensitive to myeloma?MRI
Where is the most rare place to get myeloma?Distal to the elbows and knees.
What symptoms will the patient present with in the case of myeloma?Mild pain that is worse on weightbearing, malaise, and fever.
Which modality is better than CR for showing the extent of the tumour?CT
What is metastatic disease?Haematogenous spread of malignancy from elsewhere in the body.
What is the most common type of metastatic disease?Skeletal mets
What often occurs before skeletal metastases?Lung metastases.
What are the most common sites for metastatic disease?AN


Question Answer

Section 3- Bone diseases

Question Answer
What is osteomyelitis?Infection and inflammation of the bone.
What is osteomyelitis caused by?Bacteria entering the blood stream.
What is the most common infection that causes osteomyelitis?Staphylococcus aureus

Section 4