Answer for BIR CoW 02 Sep 2018
Giant cell tumour distal radius
Findings
Well defined Expansile lytic lesion noted involving metaphysis and epiphysis of distal radius with soft tissue component. Distruption of distal radio ulnar joint. Carpal bone appear normal
Discussion
Clinical presentation Often they are incidentally identified. They may present insidiously with bone pain, soft tissue mass, or compression of adjacent structures. Pathological fracture may result in acute presentation. Location They typically occur as single lesions. Although any bone can be affected, the most common sites are around the knee: distal femur and proximal tibia: 50-65% distal radius: 10-12% sacrum: 4-9% vertebral body: 7% thoracic spine most common, followed by cervical and lumbar spine Multiple locations: ≈ 1% (multiple lesions usually occur in association with Paget disease) Radiographic features Classic appearance There are four characteristic radiographic features when a giant cell tumour is located in a long bone occurs only with a closed growth plate abuts articular surface: 84-99% come within 1 cm of the articular surface well defined with non-sclerotic margin (though <5% may show some sclerosis ) eccentric Plain radiograph and CT narrow zone of transition: a broader zone of transition is seen in more aggressive giant cell tumors no surrounding sclerosis: 80-85% overlying cortex is thinned, expanded or deficient periosteal reaction is only seen in 10-30% of cases soft tissue mass is not infrequent pathological fracture may be present no matrix calcification/mineralisation MRI Typical signal characteristics include: T1 low to intermediate solid component low signal periphery solid components enhance, helping distinguish giant cell tumors with an aneurysmal bone cyst (ABC) from a pure ABC some enhancement may also be seen in adjacent bone marrow T2 heterogeneous high signal with areas of low signal intensity (variable) due to haemosiderin or fibrosis if an aneurysmal bone cyst component present, then fluid-fluid levels can be seen high signal in adjacent bone marrow thought to represent inflammatory oedema T1 C+ (Gd): solid components will enhance, helping differentiate from aneurysmal bone cysts
Findings
Well defined Expansile lytic lesion noted involving metaphysis and epiphysis of distal radius with soft tissue component. Distruption of distal radio ulnar joint. Carpal bone appear normal
Discussion
Clinical presentation Often they are incidentally identified. They may present insidiously with bone pain, soft tissue mass, or compression of adjacent structures. Pathological fracture may result in acute presentation. Location They typically occur as single lesions. Although any bone can be affected, the most common sites are around the knee: distal femur and proximal tibia: 50-65% distal radius: 10-12% sacrum: 4-9% vertebral body: 7% thoracic spine most common, followed by cervical and lumbar spine Multiple locations: ≈ 1% (multiple lesions usually occur in association with Paget disease) Radiographic features Classic appearance There are four characteristic radiographic features when a giant cell tumour is located in a long bone occurs only with a closed growth plate abuts articular surface: 84-99% come within 1 cm of the articular surface well defined with non-sclerotic margin (though <5% may show some sclerosis ) eccentric Plain radiograph and CT narrow zone of transition: a broader zone of transition is seen in more aggressive giant cell tumors no surrounding sclerosis: 80-85% overlying cortex is thinned, expanded or deficient periosteal reaction is only seen in 10-30% of cases soft tissue mass is not infrequent pathological fracture may be present no matrix calcification/mineralisation MRI Typical signal characteristics include: T1 low to intermediate solid component low signal periphery solid components enhance, helping distinguish giant cell tumors with an aneurysmal bone cyst (ABC) from a pure ABC some enhancement may also be seen in adjacent bone marrow T2 heterogeneous high signal with areas of low signal intensity (variable) due to haemosiderin or fibrosis if an aneurysmal bone cyst component present, then fluid-fluid levels can be seen high signal in adjacent bone marrow thought to represent inflammatory oedema T1 C+ (Gd): solid components will enhance, helping differentiate from aneurysmal bone cysts
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!