Orbital Tumors - Lymphangioma
Description of Orbital Lymphangioma
Hemangioma and venous lymphatic malformation are the two most common orbital vascular lesions seen in the pediatric patient. Orbital Lymphangioma are benign hamartomatous tumours and could have an aggressive nature. Lymphangioma is rare, and constitutes less than 7% of orbital tumours. It usually presents with slow growth and a gradually progressive proptosis that is mild initially. The tumour is thought to be congenital, slow growing, and could not become clinically apparent for months or even years. It occurs in children and teenagers, but most often in the initially decade of life.
Symptoms of Orbital Lymphangioma
Most orbital lymphangiomas are initially asymptomatic, and progress gradually, manifesting as proptosis, eye pain and disturbed vision. Other symptoms include blurry vision, double vision, red eye, bulging eye, droopy eyelid, glaucoma, and vision loss. More than 50% of lymphangiomas affect anterior structures such as conjunctiva and adnexa. Orbital lymphangiomas are differentiated from hemangiomas in that orbital lymphangiomas never regress, while hemangiomas do. Spontaneous bleeding occurs within the tumour in 55% of patients causing cysts of blood called ‘Chocolate Cysts’. If the cyst forms behind the eye ball it causes proptosis, compressive optic neuropathy and loss of vision. Vascular changes can occur in the conjunctiva manifesting as “lympangiectasias”.
Diagnosis of Orbital Lymphangioma
Lymphangioma usually presents as a sudden painful bulging of the affected eye, with or without history of facial trauma or that the tumour or proptosis started right after an upper respiratory tract infection. Examination of anterior segment of the eye reveals bluish discoloration of blood vessels within the skin of the eye lid. The blood vessels can often extend underneath the conjunctiva, called lymphangiectasias. Substantial cases could be associated with corneal exposure, ulceration and optic nerve damage.
Ultrasound is the initially line of investigation for any patient with a typical history of pain with proptosis. To establish the diagnosis of lymphangioma, computed tomography (CT) or Magnetic Resonance Imaging (MRI) can be done, which can also demonstrate extra-orbital extensions.
Treatment of Orbital Lymphangioma
Orbital lymphangioma is an unusually slow growing tumour and commonly monitored by observation for growth, both clinically and radiographically prior to considering definitive intervention. The following flag signs are indicative of a more severe form of orbital lymphangioma and the need for active intervention:
- Sudden spurt in tumour growth
- Optic nerve compression
- Corneal exposure problems like keratitis sicca
- Vision loss
Most orbital lymphangiomas are poorly defined in their extensions and hence en mass removal is out of the question. Most patients are treated with several debulking surgeries to relieve acute optic nerve compression or corneal exposure. In rare cases, these patients could require exenteration of the orbit, or radiation therapy for pain relief.
With regard to treatment, orbital lymphangioma is a challenging disease and often difficult to treat with good visual outcome. It is also notorious for cosmetic complications and the possibility of frequent recurrences.