A possible cause of misdiagnosis in tumors of the axilla: schwannoma of the brachial plexus

The Authors report a rare case of a 57 years old man affected by a left radial nerve schwannoma that occurred as an asymptomatic lesion of the axilla. At clinical examination the lump was undistinguishable from the most common axillary lymphadenopathy. A lymphoadenopathy was erroneously diagnosed with ultrasonography (US). This mistake was due to the low specificity of the instrumental methodology and to the rarity of an asymptomatic schwannoma of the infraclavicular brachial plexus. The neoplasia was excised without using the microscope. In the early post-operative follow up, a “falling” attitude of the wirst, the hand and the fingers appeared, peculiar for a lesion of the radial nerve. Furthermore a hypoaesthesia of the skin of first finger and of the first interosseus space was associated. The sensitive and motor electromyography showed a radial nerve suffering. The “stupor” of the nerve trunk was treated with steroid therapy for 7 days and the patient underwent to some series of neuro-rehabilitative physical therapy for 12 weeks. The postoperative total body CT, showed that the lesion was unique: therefore it was possible to exclude the diagnosis of neurofibromatosis. After 28 months electromyography and axillary US were performed showing the complete resolution of the motor and sensitive deficit and the absence of local recurrence.