Abstract
Background Compression of the median nerve by a tumour in the elbow and forearm region is rare.
We present a case of neuropathy of the median nerve secondary to compression by giant
lipoma in the proximal forearm.
Case presentation A 46-year-old man presented with a six month history of gradually worsening numbness
and paresthesia on the palmar aspect of the left thumb and thenar eminence. Clinical
examination reveals a hypoaesthesia in the median nerve area of the left index and
thumb compared to the contralateral side. Electromyography showed prolonged sensory
latency in the distribution of the median nerve corresponding to compression in the
region of the pronator teres (pronator syndrome). Radiological investigations were
initially reported as normal. Conservative treatment for one month did not result
in any improvement. Surgical exploration was performed and a large intermuscular lipoma
enveloped the median nerve was found. A complete excision of the tumour was performed.
Postoperative revaluation the X-ray of the elbow was seen to demonstrate a well-circumscribed
mass in the anterior aspect of the proximal forearm. At follow-up, 14 months after
surgery, the patient noted complete return of the sensation and resolution of the
paresthesia.
Conclusion In case of atypical findings or non frequent localization of nerve compression, clinically
interpreted as an idiopathic compression, it is recommended to make a pre-operative
complementary Ultrasound or MRI study.
