Uncommon causes of nerve compression in the distal forearm

Introduction Nerve compression by anomalous masses located at the wrist and distal forearm is an infrequent condition. They may compress underlying structures in the carpal tunnel region, causing pain and paresthesias, which leads to the wrong diagnosis of carpal tunnel syndrome. Clinical cases We present three cases of patients with symptomatology and clinical tests compatible with compression of the median nerve in the carpal tunnel but whose physical examination showed a soft mass in the distal region of the forearm which was compressing the median nerve, as demonstrated by ultrasound evaluation. Discussion The reported cases of accessory muscles or lipomas described in the literature as causes of median nerve compression clinic are mainly described only after the surgical decompression of the carpal tunnel, due to the maintenance of residual symptoms. Conclusion Careful examination with an ultrasound evaluation prior to surgery may help to identify these cases and help planning surgical treatment.