Multiple Intracranial Arteriovenous Fistulas in Cowden Syndrome.

Cowden syndrome is a rare autosomal dominant disease. It is characterized by multiple noncancerous tumorlike growths called hamartomas, which typically are found in the skin, oral mucosa, thyroid, breast, and gastrointestinal tract. It carries with it a potential risk of malignant transformation, especially of the breast and thyroid. In 80% of the cases, the human tumor suppressor gene, phosphatase and tensin homolog (PTEN), is mutated in the germ line. We report a patient with Cowden syndrome who presented with generalized seizure and left anterior temporal hemorrhage and a nontraumatic subarachnoid hemorrhage due to multiple intracranial arteriovenous fistulas (AVFs). We discuss previous reports about vascular malformations in patients with Cowden syndrome and PTEN mutations. Importantly, we hypothesize that the production of multiple AVFs in our patient was associated with PTEN mutation.