Giant Vulvar Vascular Lesion in Pregnancy: A Case Report

Vulvar vascular lesions are rare entities that include both vascular tumors and vascular malformations. However, vulvar involvement is extremely rare. We report a case of a giant vulvar vascular lesion that developed during pregnancy and demonstrated rapid progression in the puerperal period. No vulvar mass was identified during the first and second trimesters. A soft mass was first detected in the right labium majus at 36 weeks of gestation, with a positive postural test. Superficial ultrasonography revealed a subcutaneous, partially cystic mass with associated vulvar varicosities, suggestive of a low-flow venous-type lesion. Between 36 and 39 weeks of gestation, no significant enlargement was observed. At 39 weeks, a cesarean section was performed due to the presence of the mass and concurrent vulvar varicosities. During the puerperal period, the lesion enlarged progressively and was accompanied by pain, numbness and compressive symptoms involving the right lower limb. Further vascular imaging, including ovarian, iliac, and lower-extremity venography, was performed to exclude pelvic vascular malformations or vascular tumors. Surgical excision was subsequently performed. Histopathological examination showed an elastic layer within the cystic wall, composed of myofibrous tissue with granulation tissue formation, consistent with venous thrombosis and thrombus organization. No pathological features suggestive of hemangioblastoma were identified.