AANEM Case Report # 33 Costoclavicular Mass Syndrome

A true costoclavicular mass syndrome associated with a brachial plexopathy is rare. We report the occurrence of a severe brachial plexopathy as a late complication of a displaced midclavicular fracture. An exuberant callus associated with the clavicular fracture acted as a mass lesion to compress the brachial plexus within the costoclavicular space (i.e., between the clavicle and the first rib). The clinical features and the electrodiagnostic findings in this patient were crucial in suggesting the diagnosis, which was subsequently confirmed by radiographic studies and surgical exploration. Surgical excision of the hyperabundant callus and freeing of the entrapped brachial plexus resulted in marked improvement of the patient’s neurological symptoms. Recognition of this uncommon complication of a clavicular fracture is important for the timely diagnosis of this treatable problem. © 1999 American Association of Electrodiagnostic Medicine Muscle Nerve 22: 412–418, 1999 AAEM CASE REPORT 33: COSTOCLAVICULAR MASS SYNDROME JOHN D. ENGLAND, MD, and ROBERT L. TIEL, MD 1 Department of Neurology, Louisiana State University School of Medicine, 1542 Tulane Ave., New Orleans, Louisiana 70112, USA 2 Department of Neurosurgery, Louisiana State University School of Medicine, 1542 Tulane Ave., New Orleans, Louisiana 70112, USA Accepted 14 August 1998 Most ‘‘traumatic’’ brachial plexopathies have an immediate onset, making the etiological diagnosis straightforward; however, some may occur with such delayed onset that the original precipitating event is overlooked. Neurovascular injuries with subsequent expanding hematomas or pseudoaneurysms can compress the plexus after a variable latent period, which can range from hours to weeks. Other delayed-onset brachial plexopathies are associated with orthopedic injuries and procedures. This report highlights the features of a delayed-onset brachial plexopathy due to a previous fracture of the clavicle. This uncommon complication of a clavicular fracture was not recognized initially by several physicians.