Isolated cavernous venous malformation of the conjunctiva: a case report

Cavernous venous malformations (CVMs), historically referred to as cavernous hemangiomas, are benign vascular lesions characterized by large, thin-walled vascular channels. Although they are commonly encountered in the orbit, isolated conjunctival involvement is extremely rare. Because conjunctival CVMs may resemble other vascular lesions, careful clinical evaluation, imaging, and histopathological examination are important for establishing the diagnosis and excluding intraocular or orbital extension. A 40-year-old man presented with a painless red mass in the right conjunctiva that had been present for approximately 20 years. The lesion remained stable for many years but had gradually increased in size over the preceding 5 years. Ocular examination revealed a vascularized, red, elevated, non-tender mass measuring approximately 1 × 1.2 mm over the temporal bulbar conjunctiva, with engorgement of the surrounding conjunctival and episcleral vessels. The lesion was soft and non-mobile, with no pulsation or change in size during the Valsalva maneuver and no blanching following topical application of 2.5% phenylephrine. Ultrasound biomicroscopy demonstrated that the lesion was confined to the conjunctiva without scleral or intraocular extension, while B-scan ultrasonography showed no posterior segment abnormality. Given the gradual progression and cosmetic concern, the patient elected surgical removal. Complete excision was performed without complications. Histopathological examination demonstrated multiple large, irregular vascular channels lined by a single layer of endothelial cells within hyalinized connective tissue. Immunohistochemical staining was positive for CD31 and CD34 and negative for podoplanin D2-40, supporting the diagnosis of a conjunctival CVM. The postoperative course was uneventful, with no evidence of recurrence at 1-year follow-up. Isolated conjunctival CVM is a rare vascular lesion that should be considered in the differential diagnosis of a slowly progressive conjunctival vascular mass. Imaging is valuable for assessing lesion extent, while histopathological and immunohistochemical evaluation confirms the diagnosis. In this case, complete surgical excision provided a favorable outcome without complications or recurrence at 1 year.