A Vascular Malformation Presenting as a Peripheral Nerve Sheath Tumor

Abstract We present the case of a venous malformation (VM) masquerading as a schwannoma. VMs are thin-walled vascular dilations of various sizes that typically present as soft, compressible, blue masses that are associated with pain or dysesthesia. VMs are commonly found in the head and neck as well as the distal extremities. Notably, slow-flow VMs are hypointense on T1-weighted imaging, hyperintense on T2-weighted imaging, and enhance markedly with contrast. However, VMs tend to be poorly circumscribed and fraught with venous lakes and phleboliths. Conservative therapy and sclerotherapy are the primary treatment options. In this case report, we present a VM presenting near the neurovascular bundle of the upper extremity axilla. Our case is unique in that the patient presented with symptoms and imaging qualities characteristic for a peripheral nerve schwannoma.