Venous vascular malformation of the floor of mouth masquerading as a dermoid tumor

Venous vascular malformations (VVMs) are described as abnormal post-capillary lesions which exhibit low flow. These are typically malleable and may grow with endocrine fluctuations. A VVM that mimics the classic appearance of dermoid tumor on imaging has never been reported. We encountered a 43-year-old woman with intermittent dysphagia relating to a firm submandibular mass. Physical exam and cross-sectional imaging revealed features consistent with variant dermoid cyst. However, catheter angiography eventually demonstrated a VVM which possessed vessels of variable size and partial thrombosis. We report the case and propose that catheter angiography remains important in cases where vascular malformation is considered.