Intramuscular Lipoma: An Uncommon Cause of Carpal Tunnel Syndrome

Introduction Carpal tunnel syndrome is an exceptionally common median nerve entrapment neuropathy. It is rarely caused by space occupying lesions, such as lipomas, and in such cases these lesions are usually located within the carpal tunnel. Lipomas are the most common soft tissue tumor encountered in the body, with less than 1% occurring in the hand. Case Report Reported is a case of a 55-year-old female with symptoms of carpal tunnel syndrome secondary to an extra-carpal tunnel, thenar intramuscular, lipoma. Surgical excision of lipoma with concomitant carpal tunnel decompression resulted in full neurological recovery. Discussion Intramuscular lipomas, even when extra-carpal tunnel in location, can result in carpal tunnel syndrome, secondary to increased pressure in the palmar space resulting in increased pressure in the carpal tunnel. Clinical history and a comprehensive physical examination are critical in the diagnosis of carpal tunnel syndrome. Carpal tunnel decompression and lipoma excision on their own provide an excellent prognosis, when used in combination for treatment of a rare intramuscular lipoma of the thenar musculature, they provide excellent patient recovery and outcomes, as demonstrated by this interesting case.