5. • Benign but aggressive tumours that arise from the metaphysis of long bones
Pathology
• Cell of origin uncertain but the cells are thought to be derived from primitive
mesenchymal cells.
• These cells express RANKL and have features of osteoblastic progenitors.
• F>M
• Age: 20-40
• Location: distal femur > proximal tibia > distal radius > sacral ala
• Association – Paget’s disease, Goltz syndrome
6. Clinical features
• Pain
• Swelling
• Pathological fracture -5-12%
Examination
• palpable mass/swelling
• tenderness
• decreased range of motion around affected joint
• Antalgic gait
7. Imaging
Plain radiograph
• X-ray affected extremity
• Findings - eccentric location; soap bubble appearance, expansile lesion
• CXR - for lung metastasis
CT
• For lung metastases - benign
MRI
• To assess extent of lesion
8.
9. Staging
Campanacci Grading
• Grade I - Intraosseous lesion with a well-circumscribed border and a boney
border that is intact.
• Grade II - Intraosseous lesion that is more expansile with a thinned cortex but no
loss of cortical continuity.
• Grade III - Extraosseous radiolucent lesion with cortical breakthrough and soft
tissue extension.
11. Prognoses
• 50% risk for recurrence
• Risk of malignancy < 5 %
• Poorer prognosis and high rate of local recurrence if near spinal cord.
• Recurrence rate 50% for intralesional curettage without a local adjuvant.
Differential Diagnoses
• Brown tumour of hyperparathyroidism
• Chondroblastoma
• Osteosarcoma
12. Complications
• Pathological fractures
• Surgery can result in functional compromise.
• Denosumab can lead to osteonecrosis of the jaw
• Radiation increases the risk of malignant transformation.
14. SIMPLE BONE CYSTS
• Are serous fluid filled lesion commonly found in metaphysis
• <20 years
• Location: proximal humerus > proximal femur > distal tibia > ilium> distal radius
• M>F 2:1
Classification
Active
• cyst is close to the physis
Latent
• if there’s distance between cyst and physis
15. Presentation
• most asymptomatic
• Pain if pathological fracture occurs
Imaging
Plain radiograph
• usually diagnostic
• Fallen leaf/ fallen fragment sign
MRI
17. ANEURYSMAL BONE CYST
• a benign tumorlike lesion that is described as "an expanding osteolytic lesion
consisting of blood-filled spaces of variable size separated by connective tissue
septa containing trabeculae or osteoid tissue and osteoclast giant cells.
– WHO
• <20 years
• M>F
• Common sites: long bones
18. Clinical features
• Swelling
• History of gradually increasing swelling
• Pain
• ± pathological fracture
• Decreased ROM
• Neurologic deficits – if spine location
19. Imaging
Plain radiograph
• The lucent area is usually well circumscribed and eccentric;
• the periosteum bulges (balloons), extending into the soft tissues, and may be
surrounded by new bone formation.
MRI
• shows fluid-fluid levels.
20. Treatment
• Curettage and bone grafting
• Radiation - surgically inaccessible vertebral lesions that are compressing the spinal
cord
22. • Osteosarcoma is the 2nd most common primary bone tumor
• It is a highly malignant primary bone tumour
• It arises from primitive mesenchymal bone-forming cells, and is characterised by
production of osteoid or bone by the tumour cells
• Age: 10 to 25
• Bimodal distribution of occurrence
• - 1st peak is the 10-14 years of age is most common
• - 2nd peak is in patients over 65 with Paget's disease and in those who have
received prior radiation
• Males > females
23. Classification
• Based on clinical setting
1. Primary
2. Secondary
• Based on dominant histo-morphology
1. Osteoblastic - greyish-white
2. Chondroid - opalescent and bluish grey
3. Fibroblastic - fish flesh sarcomatous appearance
4. Osteolytic - areas of tumour necrosis and blood filled spaces within tumour
mass
24. Primary Osteosarcoma
• Age - 15-25yrs
• location – distal end of femur > proximal tibia > upper end of humerus
• Gross appearance – depends on dominant histo-morphology/ mixed
• histology - anaplastic mesenchymal parenchyma with tumour cells
surrounded by osteoid
31. SECONDARY OSTEOSARCOMA
• This is an osteosarcoma developing in a bone affected by a pre-malignant
disease.
• Example : Paget’s disease, Diaphysial aclasis, Enchondromatosis, Post-radiation
• The tumour is usually less malignant than the primary osteosarcoma. It is seen in
the older age group
• Common in older age groups - after 40 years
32. PAROSTEAL OSTEOSARCOMA
• This is a type of osteosarcoma, arising in the region of the periosteum.
• It is a slower growing tumour, seen in adults.
• The common site - lower-end of the femur.
• Prognosis is better.
33. Take Home Message
• Giant cell tumours usually recur and whilst rare, metastases to lungs occur.
• Simple bone cyst – proximal long bones of children
• Aneurysmal bone cyst – more aggressive, expanding
• ABC is more expansive than UBC (UBC lesion usually not wider than physis)
• Osteosarcoma is the second most common primary malignant bone tumour
• Tumour new bone formation is characteristic for osteosarcoma
34. References
• Bajaj, A. (2020, June 06). The gargantuan benevolence - osteoclastoma. Retrieved from
OpenAccessText: https://www.oatext.com/the-gargantuan-benevolence-
osteoclastoma.php#Article_Info
• Ben Sharareh MD, P. O. (2021, 06 22). Giant Cell Tumor. Retrieved from Orthobullets:
https://www.orthobullets.com/pathology/8046/giant-cell-tumor
• Charles T Mehlman, D. M. (2021, May 04). Unicameral (Simple) Bone Cyst Clinical
Presentation. Retrieved from Medscape:
https://emedicine.medscape.com/article/1257331-clinical
• Ebnezar, J. (2010). Textbook of Orthopedics. New Delhi: JAYPEE BROTHERS MEDICAL
PUBLISHERS.
• MAHESHWARI, J. (2014). Essential Orthopaedics. New Dehli: Jaypee Brothers Medical
Publishers .
• Michael J. Joyce, M. (2020, June). Primary Malignant Bone Tumors. Retrieved from MSD
MANUAL: https://www.msdmanuals.com/professional/musculoskeletal-and-
connective-tissue-disorders/tumors-of-bones-and-joints/primary-malignant-bone-
tumors?query=osteosarcoma
• Kuhn J, Sapra A. Osteoclastoma.[Updated 2021 Sep 18]. In: StatPearls [Internet]. Treasure Island (FL):
StatPearls Publishing;2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK551681/
