Orbital Cavernous Haemangioma

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.

References

Shields Jerry A, Shields Carol L. Eyelid, Conjunctival, and Orbital Tumors- An Atlas and Textbook Second Edition. Lippincott Williams & Wilkins, a Wolters Kluwer business 2008. P 522- 523.

Jäger H Rolf, Gillard Jonathan H. Grainger & Allison’s Diagnostic Radiology- Neuroimaging Sixth Edition. Elsevier Ltd. 2016. P 184- 188.

Denniston Alastair KO, Murray Philip I. Oxford Handbook of Ophthalmology Third Edition. Oxford University Press 2014. P 618.

Bloom HJG, Lemerle J, Neidhardt MK, Voûte PA. Cancer in Children- Clinical Management. Springer- Verlag Berlin Heidelberg 1975. P134- 135.

http://eyewiki.aao.org/Cavernous_hemangioma

https://emedicine.medscape.com/article/1218120-overview

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3557012/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2747469/

Symptoms may include

• Painless slowly progressive proptosis
• Diplopia
• Orbital mass may be present (extraconal lesions)
• Diminution of vision (Rare)
• Amaurosis (Rare).

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.

Histopathology

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.

Investigations

• Magnetic resonance imaging (MRI): Cavernous haemangioma mostly shows low T1 signal and high T2 signal with variable enhancement. Dynamic post gadolinium MRI shows progressive spread of enhancement from a single point or small component of the mass. This is a characteristic feature of Cavernous haemangioma. This helps in monitoring of tumours where conservative approach is considered instead of surgical therapy.
• Computerised axial tomography (CAT): It may show well circumscribed intraconal lesion with mild to moderate enhancement. There may be areas of thrombosis.
• Ultrasonography: Ultrasonography shows well defined, round intraconal lesion with high internal reflectivity.

Differential Diagnosis

• Lymphangioma
• Neurofibroma
• Schwannoma
• Fibrous histiocytoma
• Melanoma
• Solitary fibrous tumour
• Haemangiopericytoma

Conservative therapy

Small, asymptomatic orbital Cavernous haemangioma may be observed periodically for any growth and increase in size.

Surgical therapy

Surgical therapy may be required for larger and symptomatic tumours. Complete and meticulous excision is necessary to avoid recurrence.

• Conjunctival or cutaneous approach: Conjunctival or cutaneous approach may be used for removal of anterior lesions.
• Lateral orbitotomy: Lateral orbitotomy may be required to remove deep tumours. Sometimes, it is done along with osteotomy.
• Trans-cranial approach: Trans-cranial approach may be used for lesions localised at the orbital apex.

Prognosis

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.