True about hemangioma of bone -a) Mostly symptomaticb) Peak incidence in 5th decadec) Constitute 10-20% of total bone tumord) Overgrowth of bone occurse) hematogenous spread
Haemangioma 

This bengin lesion, probably a hemartoma, is composed of vascular spaces lined by endothelial cells.
They constitute 1-1.5% of all primary bone neoplasms.
It has a peak incidence in the fifth decade (according to Maheshwari young adults).
About 50% of hemangiomas of bone occur in vertebrae and are most commonly situated in lower thoracic and upper lumbar regions.
Other coinmon site of involvement (20%) is skull.
Small bones of hands and feets may also be affected.
Haemangioma of the vertebra has a typical radiographic picture in the form of loss of horizontal striations and prominence of  vertical striations. There is Polka dot appearance on CT.
In the skull, hemangioma generally affects the calverium and is seen as an expansile lytic lesion which has a sunburst appearance with striation radiating from the centre.
A hemangioma may be identified due to associated phlebolith and it may cause local gigantism of the invovled area.
Hemangiomas are largely asymptomatic, and thus most are never discovered, leading some to describe these lesions as rare.
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