Cavernous Venous Malformation
Cavernous venous malformations (CVMs) are nondistensible, low-flow vascular lesions previously known as cavernous hemangiomas. They are the most common type of primary orbital lesion in adults, typically presenting in the fourth and fifth decades of life. Women represent 60% of cases, and circulating estrogen and progesterone levels may play a role in clinical progression, with growth sometimes accelerating during pregnancy.
CVMs typically produce slowly progressive, painless proptosis (Fig 5-4A). Other findings may include retinal striae, hyperopia, optic nerve compression, increased IOP, and strabismus. Contrast-enhanced orbital imaging shows a stippled pattern in the early phase of contrast that develops into homogeneous staining in the late phase. The lesion appears as a well-circumscribed mass that can have an intraconal and/or extraconal component (Fig 5-4B, C). Chronic lesions may contain radiodense phleboliths. Arteriography and venography typically do not aid in the diagnosis as these lesions have very limited communication with the systemic circulation.
Figure 5-4 Cavernous venous malformation (CVM). A, Proptosis of the left eye as a result of CVM. B, Coronal computed tomography (CT) scans show a well-circumscribed lesion the muscle cone. C, Axial (left) and sagittal (right) CT scans show the mass.D, Intraoperative traction with a cryoprobe facilitates complete removal of the mass.
(Courtesy of Bobby S. Korn, MD, PhD.)
On histologic examination, CVMs are encapsulated and composed of large cavernous spaces with walls of smooth muscle containing red blood cells.
Treatment consists of complete surgical excision if the lesion compromises visual function, causes significant proptosis, or demonstrates substantial growth. The growth potential of a CVM is not predictable at the time of diagnosis or following incomplete resection; in rare cases, these lesions may involute spontaneously.
Because they are encapsulated and relatively isolated from the surrounding tissue, CVMs are often easier to remove than many other orbital tumors. Coronal imaging helps determine the position of the CVM relative to the optic nerve, and the surgical approach is dictated by the location of the lesion. Deeper lesions may be attached to vital (and sometimes vascular) structures within the orbital apex, so their complete excision may not always warrant the risks. Radiotherapy can be considered for lesions located deep within the orbital apex.
Calandriello L, Grimaldi G, Petrone G, et al. Cavernous venous malformation (cavernous hemangioma) of the orbit: current concepts and a review of the literature. Surv Ophthalmol. 2017;62(4):393–403.
Hill RH 3rd, Shiels WE 2nd, Foster JA, et al. Percutaneous drainage and ablation as first line therapy for macrocystic and microcystic orbital lymphatic malformations. Ophthalmic Plast Reconstr Surg. 2012;28(2):119–125.
Rootman J, Heran MK, Graeb DA. Vascular malformations of the orbit: classification and the role of imaging in diagnosis and treatment strategies. Ophthalmic Plast Reconst Surg. 2014;30(2):91–104.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.