Brown tumor
Updates to Article Attributes
Brown tumour (also known as osteitis fibrosa cystica or rarelyosteoclastoma) is one of the manifestations of hyperparathyroidism. It represents a reparative cellular process, rather than a neoplastic process.
Epidemiology
Brown tumours have a slightly greater frequency in primary than than in secondary hyperparathyroidism (3% versus 2%). However, secondary hyperparathyroidism is much more common than primary hyperparathyroidism, therefore most of brown brown tumours that are seen are associated with secondary hyperparathyroidism.
PathogenesisPathology
In chronic renal disease, continual, and excessive urinary calcium excretion can lower serum calcium level and lead to a rise in parathormoneparathyroid hormone secretion where. This results in moblisation of skeletal calcium is mobilisedthrough rapid osteoclastic turnover of bone to maintain normal serum calcium levels.
This mobilisation occurs through rapid osteoclastic turnover of bone, a direct effect of parathormone.
In localised regions where bone loss is particularly rapid, haemorrhage, and reparative granulation tissue, andwith active, vascular, proliferating fibrous tissue may replace the normal marrow contents, resulting in a brown tumor.
Haemosiderin imparts the brown colour (hence the name of the lesions).
Radiographic features
Plain filmradiograph
Well-defined, purely lytic lesions that provoke little reactive bone. The cortex may be thinned and expanded, but will not be penetrated.
CT
Attenuation values on CT will be in the range of blood and fibrous tissue.
MRI
The MRI appearance depends on the relative proportion of its components. The lesions therefore may be solid, cystic, or mixed. Solid components are intermediate to low intensity on T1- and T2-weighted images, while the cystic components are hyperintense on T2-weighted images and may have fluid-fluid levels.
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T1 C+ (Gd): there can be enhancement of the solid component and septa
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Angiography
Lesions
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lesions are usually hypervascular
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Nuclear medicine
Bone scanOften
See alsoDifferential diagnosis
- mnemonic for the differential diagnosis of a benign, lytic bone lesion: FEGNOMASHIC
-<p><strong>Brown tumour </strong>(also known as <strong>osteitis fibrosa cystica </strong>or rarely <strong>osteoclastoma</strong>) is one of the manifestations of <a href="/articles/hyperparathyroidism">hyperparathyroidism</a>. It represents a reparative cellular process, rather than a neoplastic process.</p><h4>Epidemiology</h4><p>Brown tumours have a slightly greater frequency in primary than in secondary hyperparathyroidism (3% versus 2%). However, secondary hyperparathyroidism is much more common than primary hyperparathyroidism, therefore most of brown tumours that are seen are associated with secondary hyperparathyroidism.</p><h4>Pathogenesis</h4><p>In chronic renal disease, continual, excessive urinary calcium excretion can lower serum calcium level and lead to a rise in parathormone secretion where skeletal calcium is mobilised to maintain normal serum calcium levels.</p><p>This mobilisation occurs through rapid osteoclastic turnover of bone, a direct effect of parathormone.</p><p>In localised regions where bone loss is particularly rapid, haemorrhage, reparative granulation tissue, and active, vascular, proliferating fibrous tissue may replace the normal marrow contents, resulting in a brown tumor.</p><p>Haemosiderin imparts the brown colour (hence the name of the lesions).</p><h4>Radiographic features</h4><h5>Plain film</h5><p>Well-defined, purely lytic lesions that provoke little reactive bone. The cortex may be thinned and expanded, but will not be penetrated.</p><h5>CT</h5><p>Attenuation values on CT will be in the range of blood and fibrous tissue.</p><h5>MRI</h5><p>The MRI appearance depends on the relative proportion of its components. The lesions therefore may be solid, cystic, or mixed. Solid components are intermediate to low intensity on T1- and T2-weighted images, while the cystic components are hyperintense on T2-weighted images and may have fluid-fluid levels.</p><ul><li>-<strong>T1 C+ (Gd):</strong> there can be enhancement of the solid component and septa.</li></ul><h5>Angiography</h5><p>Lesions are usually hypervascular.</p><h5>Bone scan</h5><p>Often shows intense uptake.</p><h4>See also</h4><ul><li>mnemonic for the differential diagnosis of a benign, lytic bone lesion: <a href="/articles/lytic-bone-lesion-mnemonic">FEGNOMASHIC</a>- +<p><strong>Brown tumour </strong>(also known as <strong>osteitis fibrosa cystica </strong>or rarely <strong>osteoclastoma</strong>) is one of the manifestations of <a href="/articles/hyperparathyroidism">hyperparathyroidism</a>. It represents a reparative cellular process, rather than a neoplastic process.</p><h4>Epidemiology</h4><p>Brown tumours have a slightly greater frequency in primary than in secondary hyperparathyroidism (3% versus 2%). However, secondary hyperparathyroidism is much more common than primary hyperparathyroidism, therefore most of brown tumours that are seen are associated with secondary hyperparathyroidism.</p><h4>Pathology</h4><p>In <a href="/articles/chronic-kidney-disease">chronic renal disease</a>, continual and excessive urinary calcium excretion can lower serum calcium level and lead to a rise in <a href="/articles/parathyroid-hormone">parathyroid hormone</a> secretion. This results in moblisation of skeletal calcium through rapid osteoclastic turnover of bone to maintain normal serum calcium levels.</p><p>In localised regions where bone loss is particularly rapid, haemorrhage, and reparative granulation tissue, with active, vascular, proliferating fibrous tissue may replace the normal marrow contents, resulting in a brown tumor.</p><p>Haemosiderin imparts the brown colour (hence the name of the lesions).</p><h4>Radiographic features</h4><h5>Plain radiograph</h5><p>Well-defined, purely lytic lesions that provoke little reactive bone. The cortex may be thinned and expanded, but will not be penetrated.</p><h5>CT</h5><p>Attenuation values on CT will be in the range of blood and fibrous tissue.</p><h5>MRI</h5><p>The MRI appearance depends on the relative proportion of its components. The lesions therefore may be solid, cystic, or mixed. Solid components are intermediate to low intensity on T1- and T2-weighted images, while the cystic components are hyperintense on T2-weighted images and may have fluid-fluid levels.</p><ul><li>
- +<strong>T1 C+ (Gd):</strong> there can be enhancement of the solid component and septa</li></ul><h5>Angiography</h5><ul><li>lesions are usually hypervascular</li></ul><h5>Nuclear medicine</h5><p>Bone scan often shows intense uptake.</p><h4>Differential diagnosis</h4><ul><li>mnemonic for the differential diagnosis of a benign, lytic bone lesion: <a href="/articles/lytic-bone-lesion-mnemonic">FEGNOMASHIC</a>