Bilateral neuropathic leg pain a manifestation of a rare disorder: Cowden syndrome - a case report

First described in 1963, Cowden syndrome is a rare disorder inherited in an autosomal dominant manner. 85% of them have a detectable PTEN mutation. 34 year old male with history of schizoaffective disorder and seizures presented with bilateral stabbing leg pain and numbness. His pain radiates from his back to the lateral, medial and posterior side of his both legs. He had a thyroid nodule, left sided gynecomastia, small papules on his face and his head circumference was at the 97th percentile. His mother, sister and son have macrocephaly, multiple lipomas and cancers. PTEN genetic testing came back positive for the Y16X mutation in the PTEN gene. Nerve conduction studies did not show any evidence of lumbosacral radiculopathy or peripheral polyneuropathy in the lower extremities. EMG was not indicated per neurology. MRI of the entire spine showed only early degenerative changes in the cervical spine. PET scan was nonsignificant. He was tried on number of medications including duloxetine, pregabalin, hydrocodone and NSAIDS. He was finally started on neurontin and his pain dramatically decreased after he reached the dose of 2400 mg/day. A colonoscopy showed multiple ganglioneuromas. The PTEN gene encodes the phosphatase and tensin homolog (PTEN) protein and regulates the cell cycle. Thus PTEN acts as a tumor suppressor. A mutation of this gene leads to the development of many cancers as well as non-cancerous growths. Among the few CNS manifestations this is the first case report of neuropathic leg pain associated with this syndrome.