Giant Cell Lesions of the Bone Flashcards
1
Q
What is a giant cell lesion of the bone
A
- Lesions that arise in and destroy bone and are rich in osteoclast giant cells
- Defined by their histological appearance
- Doesn’t include foreign body granuloma, TB, sarcoidosis… All have giant cells but not in bone
2
Q
What is the classification of giant cell lesions of the bone
A
- Giant cell granuloma
a. Central giant cell granuloma
b. Peripheral giant cell granuloma (giant cell epulis) - Brown tumour of hyperparathyroidism
- Anerusymal bone cyst
- Cherubism
3
Q
Clinical features of central giant cell granuloma
A
- Solid lobulated mass of proliferating vascular connective tissue packed with giant cells (osteoclasts)
- Benign tumour of unknown aetiology
- More common in young females, but seen over a wide age range
- Forms in alveolar ridge, anterior to 6s, more frequently in mandible but often in maxilla
- Very expansible and may be destructive. May penetrate cortical bone and periosteum to produce a purplish soft tissue swelling
- Frequently a slow-growing painless swelling, but growth is sometimes rapid
- Lesions are typically several cm across
- No association with hyperparathyroidism
4
Q
Histological features of central giant cell granulomas of bone
A
- Same as brown tumour of hyperparathyroidism and cherubism
- Many multinucleate giant cells
- Stroma of fibroblasts and mononuclear cells
- Arranged in lobules separated by fibrous tissue septa, and sometimes a thin layer of osteoid or bone forms in them, hence honeycomb appearance on rx
- Vascular and lots of haemorrhage - hence colour change clinically
5
Q
How are central giant cell granulomas diagnosed
A
- Expansion ± soft tissue mass
- Bluish/maroon colour
- Radiology, biopsy
- Exclude hyperparathyroidism
6
Q
What are the radiographic features of central giant cell granulomas
A
- Radiolucent, well defined and scalloped outline
- Unilocular or multilocular
- Surrounded teeth may ‘float in air’ be displaced of occ resorbed (if very large)
- Can make teeth mobile
- May contain wispy opaque lines or honeycomb pattern
7
Q
What is the treatment for central giant cell granulomas
A
- Many granulomas grow slowly, and some have been shown to resolve spontaneously
- However, the majority enlarge and require removal by curettage
- ~15% of lesions recur, but a second curettage is usually curative
- Fast growing granulomas indicate a higher risk of recurrence - surgery to excise the lesion with surrounding bone, particularly in the maxilla and facial bones where effective curettage in thin bones is difficulty to achieve
- Maybe medical tx to partially control growth (used for rapidly enlarging Examples, when pt factors prevent immediate surgery or in children where facial growth might be affected by surgery)
[injection of corticosteroids converts lesions to fibrous tissue, calcitonin, interferon alpha, bisphosphonates]
8
Q
What are the clinical features of peripheral giant cell granulomas
A
- ‘Giant cell epulis’
- Unrelated gingival hyperplastic lesion (arises on gingiva)
- No lesion in underlying bone
- Histologically identical to the central lesion but is superficial and outside cortical bone
- All ages, but commoner in children
- Bluish maroon colour clinically
- Local cause, often recent loss primary tooth
- Tx: complete excision
9
Q
What does an overproduction of parathyroid hormone (PTH) cause? And what can cause the overproduction?
A
- Mobilises Ca from the skeleton and raises the plasma Ca level. Ca then lost in urine and can lead to renal stone formation and renal damage
- Primary hyperparathyroidism: Causes is usually an adenoma of the parathyroid glands, uncommonly hyperplasia of the gland and rarely a parathyroid carcinoma
- Secondary hyperparathyroidism: PTH hyper secretion in reaction to low Ca levels causes by vitamin D deficiency, gut malabsorption of Ca or renal failure (as kidney enzymatically activate Vit D)
10
Q
What are the features of browns tumours of hyperparathyroidism
A
- Common: malaise, hypertension, peptic ulcer and kidney stones
- Significant bone disease now uncommon due to early tx
- Generalised rarefaction of bone, loss of density and lamina dura
11
Q
What causes brown tumours
A
- Foci of osteoclasts in highly vascular stroma
- Extensive internal haemorrhage
- Breakdown of erythrocytes producing haemosiderin pigment and colours the lesion brown
- Histologically indistinguishable from giant cell granuloma of the jaw
12
Q
How do browns tumours of hyperparathyroidism present radiographically
A
- Reduced bone density, loss of trabecular pattern and definition of lamina dura
- In severe disease, these changes are more marked and pt may also develop one or more brown tumours (cyst like unilocular/multilocular radiolucencies)
- Bony changes can cause pathological fractures but reverse with tx
13
Q
What is the treatment for browns tumours of hyperparathyroidsm
A
- Treat underlying condition
- Primary
surgical removal of causative adenoma - Secondary
Ca supplementation to counter losses and correct any remediable underlying renal disease if possible
14
Q
What are the two types of anerusymal bone cysts
A
- Primary: benign neoplasms of bone; genetic (USP6 gene activated)
- Secondary: develop in association with Fibro-osseous and other lesions, and are not neoplasms
15
Q
What are the clinical features of aneurysmal bone cysts
A
- Replace and expand bone with a vascular soft tissue containing numerous giant cells
- Rapidly growing painless swelling => ballooning expansion
- Rare in jaws; jaw lesions usually in mandibular ramus and angle
- Affects pts usually between 10-20y
- Form very expansile soap-bubble radiolucencies
