Perineural cyst presenting like cubital tunnel syndrome.

Perineural cysts are believed to be asymptomatic; however, they rarely cause symptoms related to nerve root compression. Cervical symptomatic perineural cysts are in fact exceedingly rare. There are no reported cervical perineural cysts in the literature that present like cubital tunnel syndrome. A patient with motor weakness of the abductor and adductor muscles of the fingers of the left hand and hypoesthesia in the hypothenar region of the left hand presented at our clinic. A neurological examination, and neuroradiological and electrophysiological evaluations supported the finding that the patient's clinical condition was caused by a perineural cyst located around the C8 neural root. The neurological symptoms of the patient markedly improved after medical treatment. We reported the first cervical perineural cyst as presenting like cubital tunnel syndrome patient in the literature. The visualization of perineural cyst may need extra magnetic resonance imaging (MRI) sections in order to view the nerve root through the neural foramen or extraforaminal area. These lesions are benign, and the appropriate treatment is curative.