Cavernous Haemangioma is the most common primary orbital tumour in adults. This lesion consists of angiographically silent venous malformation. The classification of Cavernous haemangioma is a misnomer. It is usually centered on intraconal compartment of orbit and may contain phleboliths visible on imaging. Cavernous haemangioma consists of venous malformation having vascular spaces lined with endothelium and a fibrous pseudo-capsule. Rarely, cavernous haemangioma may be intra-osseous, and thus lies in extraconal compartment.
Cavernous haemangioma may occur in different parts of the eye and adnexa viz. orbit, eyelid, retina and uveal tract. Haemangioma produces proptosis of the eyeball. Sometimes, it causes marked proptosis which may be accentuated due to vascular engorgement. It usually does not decrease in size with passage of time. It rarely, if ever, causes visual impairment and generally, binocularity is not affected in axial proptosis.
Symptoms may include
Cavernous haemangioma is a benign tumour that is usually seen in adults as relatively stationary or slowly progressive mass. It is a hamartoma composed of dilated large vascular spaces.
The classification as a tumour is a misnomer, since this represents an angiographically silent venous malformation consisting of vascular spaces lined with endothelium.
Clinically, Cavernous haemangioma present as a relatively stationary or slowly progressive benign tumour that may produce painless proptosis. Increased growth may be seen following trauma or in pregnancy. Since it occurs in muscle cone, it produces axial proptosis. It is generally not associated with inflammatory signs. Visual function is usually not affected. Since the proptosis is in straight ahead position, binocular vision may not be compromised. With marked proptosis, the constituent vessels may get engorged as in the act of crying.
Haemangioma is cosmetically unsightly and does not decrease in size with passage of time. Rarely, it may be bilateral. Although, generally being solitary tumour, there may sometimes be multiple masses, as is seen in blue rubber bleb nevus syndrome (characterised by numerous malformations of the venous system significantly involving skin and visceral organs). Rarely, multiple confluent cavernous haemangioma may lead to simultaneous involvement of orbit and brain. There may be phleboliths seen on imaging.
Rarely, Cavernous haemangioma present as intra-osseous lesion affecting the orbital bones. Intra-osseous lesion, since being extraconal, presents with non-axial proptosis.
Cavernous haemangioma represents an angiographically silent venous malformation consisting of vascular spaces lined with endothelium and bound by a pseudo-capsule. These are separated by connective tissue that contains smooth muscle. It may contain phleboliths.
Frank haemorrhage is atypical, but hemosiderin staining may occur.
Small, asymptomatic orbital Cavernous haemangioma may be observed periodically for any growth and increase in size.
Surgical therapy may be required for larger and symptomatic tumours. Complete and meticulous excision is necessary to avoid recurrence.
The management of orbital Cavernous haemangioma is not satisfactory. The proptosis is relieved only to a limited extent by irradiation. Surgical removal of this vascular tumour by orbitotomy may not be fully successful because of the extent of lesion. Surgical procedures or even ligation of feeding vessel to tumour, do carry the risk of damage to orbital structures e.g. damage to extra-ocular muscles resulting in ophthalmoplegia.