Orbital venous anomalies

The Use of Sirolimus for Treatment of Orbital Lymphatic Malformations: A Systematic Review

PURPOSE

Orbital lymphatic malformations are rare congenital choristomas associated with pain, proptosis, exposure keratopathy, and vision loss. Current treatments of surgery, drainage, and sclerotherapy may have adverse effects including risk of damage to surrounding structures, swelling, and malformation persistence or recrudescence. Sirolimus, which inhibits mammalian target of rapamycin, a regulator of cell growth and vascular endothelial growth factor expression, has successfully treated systemic vascular malformations. However, its efficacy and safety have not yet been well established for orbital lymphatic malformations.

METHODS

Systematic review and analysis of relevant published literature were performed. PubMed, Embase, and World of Science searches were conducted for studies involving sirolimus treatment of orbital lymphatic malformations through July 2019.

RESULTS

Nine case series and reports with 10 total patients who received sirolimus for treatment of orbital lymphatic malformations were included. The age at sirolimus initiation ranged from 1 week to 23 years. The malformation was lymphatic in 6 patients, lymphaticovenous in 3 patients, and lymphatic-arteriovenous in 1 patient. Six patients underwent ineffective prior therapy including sclerotherapy, surgery, or medical therapy. Initial sirolimus dosage ranged from 0.05 mg/kg twice a day to 1 mg twice a day, and duration ranged from 6 months to 53 months. Seven patients had partial response, and 3 patients, all of whom had a microcystic malformation component, experienced complete response. Adverse effects included mild reversible leukopenia, hypertriglyceridemia, hypercholesterolemia, and transaminitis with adverse effects denied or not specified for 6 patients.

CONCLUSIONS

Sirolimus may be a safe and effective treatment for orbital lymphatic malformations, especially microcystic malformations.

[Tumors and tumor-like lesions of the orbit]

This article gives an overview of the most common and clinically relevant tumors of the orbit and their treatment. The most common orbital tumors in childhood are cystic tumors, such as dermoid and epidermoid cysts. Capillary hemangiomas are the most common primary benign tumors of the orbit and appear mostly in the first year of life. In contrast teratomas are rare and histologically mostly benign. Neural tumors are, for example, gliomas of the optic nerve and in 25-50% of cases are associated with neurofibromatosis. Rhabdomyosarcoma is a rapidly growing malignant orbital tumor whereby the stage and localization are the most important prognostic factors for survival chance in children. Leukemia can be associated with a chloroma especially in the first decade of life. Lymphoproliferative diseases, vascular and cystic tumors in particular are known as tumors of adulthood. In addition to fibroosseous and mesenchymal tumors, neural forms, such as schwannomas are also important. Secondary tumors of the orbit are often manifested in the nose and paranasal sinuses.

[Vascular lesions of the orbit in children]

Vascular lesions of the orbit in children are most often hemangiomas and lymphangiomas. Hemangioma is a tumor that tends toward spontaneous regression. Lymphangioma is a malformation that tends to increase in size with growth spurts that can occur until adulthood. The treatment is decided according to the functional impact.

Orbital Decompression for Gross Proptosis Associated With Orbital Lymphangioma

A 14-year-old boy with 11 mm of proptosis and exposure keratopathy secondary to an orbital lymphangioma underwent surgical debulking with a carbon dioxide laser through a lateral orbitotomy combined with a 3-wall orbital decompression. The proptosis was reduced by approximately 2 mm as a result of the debulking procedure, but a further 5 mm reduction was achieved with the orbital decompression. No serious adverse effects were encountered. Bony orbital decompression may be a useful alternative treatment in patients with severe proptosis secondary to orbital lymphangioma.

Orbital venous-lymphatic malformations (lymphangiomas) mimicking cavernous hemangiomas

PURPOSE

To illustrate that orbital venous-lymphatic malformations (lymphangiomas) may rarely simulate cavernous hemangiomas.

METHODS

Retrospective case review.

RESULTS

Five patients were identified from a series of 85 patients with venous-lymphatic malformations. The age range was 21 to 69 years, and all cases presented with a history of slowly progressive or long-standing proptosis. Computerized tomography revealed relatively homogeneous intraconal masses that were well defined anteriorly. Two of the cases had expansion of the orbit, and one had focal calcification. The three who had magnetic resonance imaging showed heterogeneous contrast enhancement. The preoperative diagnosis in every case was cavernous hemangioma, and intraoperatively the lesions resembled cavernous hemangiomas. However, posterior dissection was difficult in all patients because of dense adhesions and, in one case, led to a central retinal artery occlusion. The histology was characteristic of orbital venous-lymphatic malformations in all five cases.

CONCLUSIONS

Deep orbital venous-lymphatic malformations presenting in adulthood may be rarely confused with cavernous hemangiomas. In doubtful cases, significant intralesional heterogeneity, best seen on magnetic resonance imaging, and focal calcification may help distinguish the two entities. This differentiation is important, because dissection of venous-lymphatic malformations is fraught with more complications than surgical excision of a cavernous hemangioma.