Osteoblastoma of hamate

Clinical Cases 20.11.2003
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Section: Musculoskeletal system
Case Type: Clinical Cases
Patient: 17 years, male
Authors: Ramachandra S, Prabhudesai V, Win TZ, Lapsia S
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Details
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AI Report

Clinical History

Patient presented with pain in the right wrist.

Imaging Findings

The patient presented with pain in the right wrist. Plain X-ray, bone scan and CT scan of the hand were performed.

Discussion

Osteoblastoma is a benign relatively uncommon primary neoplasm of bone that is capable of malignant transformation. It represents 1% of all primary bone tumours. Males are affected more frequently than females with a ratio of 2:1. At least 80% of the individuals affected are less than 30 years of age. Although osteoblastoma can affect any bone, it is common in spine (33-37%) and long bones (26-32%). In the spine, osteoblastomas arise typically from dorsal elements. Small bones of hands and feet are affected in 15-26% of cases and occur rarely in carpel bones (8%). Long insidious history of pain is the commonest symptom. Other symptoms include localised swelling, tenderness and decreased range of motion. Spinal lesions may be accompanied by painful scoliosis and neurological manifestation including paraesthesia and weakness.
Pathologically the lesion is larger than an osteoid osteoma and measures greater than 2cms. It may have a subperiosteal, cortical or medullary location. It contains abundant osteoid tissue and vascular connective tissue stroma with interconnecting trabecular bone.
Radiologically an area of radiolucency is typical that measures 2-10cms. Margins are irregular but sharply demarcated. Expansion of bone, cortical thinning and a soft tissue mass may accompany the lesion. It is slow growing and thus remodelling occurs with periostitis and varying degree of bone sclerosis. Calcification or ossification of osteoid tissue within the tumour can cause punctate or amorphous increase in density. Isotope bone scan shows intense focal accumulation of the agent.
In summary the appearances of osteoblastoma is highly variable and will have to be differentiated from osteoid osteoma, aneurysmal bone cyst, eosinophilic granuloma, enchondroma, fibrous dysplasia, chondromyxoid fibroma or solitary bone cyst. In cases of aggressive osteoblastomas, the osseous expansion and soft tissue extension that are evident radiographically can simulate the abnormalities associated with well differentiated osteosarcoma.

Differential Diagnosis List

Osteoblastoma of the hamate

Final Diagnosis

Osteoblastoma of the hamate

Liscense

Figures

Hand X-ray

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Hand X-ray

Bone Scan

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Bone Scan
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Bone Scan

CT scan

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CT scan