Fibrolipomatous hamartoma in the median nerve in the arm - an unusual location but with MR imaging characteristics: a case report.

Fibrolipomatous hamartoma of the median nerve are usually located distally in the forearm and may have characteristic features on MR imaging. Here we report a patient with an extensive fibrolipomatous hamartoma at an unusual location proximally in the arm, where a preoperative MR imaging was pathognomonic and diagnosis was verified by an incisional biopsy. We suggest that MRI should be performed in cases with nerve dysfunction without an obvious cause after a thorough clinical examination.

Magnetic resonance imaging of peripheral nerve tumours in the upper extremity.

Clinical assessment and various diagnostic tools, particularly magnetic resonance imaging (MRI), of tumours of peripheral nerves are used to get an accurate diagnosis and to plan surgical intervention. Our purpose was to examine the usefulness of MRI in assessing nerve tumours in the upper extremity. Medical records of 19 patients (20 MRI examinations) with 29 histopathologically verified benign nerve tumours were examined retrospectively. In 12/20 cases MRI suggested a correct diagnosis of the type of nerve tumour. An additional 3/20 cases had an uncertain diagnosis, but nerve relations to the tumour were established. In 5/20 cases MRI gave a doubtful diagnosis with no suspicion of the tumour being located in a nerve trunk. MRI can localise and diagnose a nerve tumour in the upper extremity in 75% of cases, but it is difficult to specify the type of tumour.

Tumours of peripheral nerves in the upper extremity: a 22-year epidemiological study.

Peripheral nerve tumours are uncommon. Our aims were to calculate the incidence and relative frequencies, to define sites of nerve tumours and to judge preoperative symptoms and outcomes of intervention. The results of 53 patients, with 68 tumours and histopathological diagnoses of true neoplasms, who had been operated on at the Department of Hand Surgery, Malmo, Sweden, between 1986 and 2007, were analysed. Schwannomas were the most common tumour (n=42). The incidence of schwannomas was 0.62/100 000 inhabitants/year in Malmo during that time period. The median nerve was most affected, closely followed by the ulnar and digital nerves. The preferred sites were the forearm, the thumb, and the digits. The most common preoperative symptom was pain. Loss of sensation was the most common postoperative complication. However, 33/53 patients (62%) were completely free of symptoms after excision. Patients should be provided with meticulous information preoperatively.