Spinal Extradural Arteriovenous Fistula with Cowden Syndrome: A Case Report and Literature Review Regarding Pathogenesis and Therapeutic Strategy

We report the case of a patient with a spinal extradural arteriovenous fistula (AVF) associated with Cowden syndrome (CS) that was successfully treated by endovascular surgery. CS is an autosomal dominant disorder associated with diverse symptoms caused by a deleterious mutation in the phosphatase and tensin homolog (PTEN) gene. A 67-year-old woman was diagnosed with CS based on her medical history of multiple cancers for which she underwent abdominal surgery, macrocephaly, Lhermitte-Duclos disease, and facial papules. Her genetic testing demonstrated a PTEN mutation. She presented with progressive paraparesis and her MRI of the thoracolumbar spine showed the spinal cord edema along with flow voids. A spinal angiogram demonstrated a spinal extradural AVF with the perimedullary drainage. The AVF was successfully treated by endovascular surgery. The PTEN mutation can accelerate angiogenesis; thus, vascular anomalies are one of the diagnostic criteria of CS. However, only two cases of vascular anomalies involving the spinal cord in patients with CS have been reported previously. As the present case, both cases had a history of abdominal or retroperitoneal cancer. The PTEN mutation accompanied with abdominal surgery might have caused this vascular anomaly as the consequences of venous congestion around the thoracolumbar spine. A spinal extradural AVF should be considered in patients with CS who present with myelopathy, especially when the patient has a history of abdominal or retroperitoneal surgery. Regarding the treatment strategy, endovascular surgery should be considered because surgical insult could prompt secondary vascular anomalies resulting from neovascularization due to the PTEN mutation.