This case report describes the rare anomaly of an absent right anterior scalene muscle presenting with the symptoms and signs of the thoracic outlet syndrome. The thoracic outlet syndrome in our patient can be attributed to the absence of the right anterior scalene muscle, which resulted in the brachial plexus being in proximity to the subclavian vein and artery in a narrowed and abnormal interscalene space. In addition, the absence of the anterior scalene muscle resulted in the neurovascular structures being compressed onto the first rib in the costoclavicular space. The most likely cause of the presentation is, however, the possibility of the presence of aberrant muscle slips, which would cause compression of the structures in the anterior (venous) and posterior (neurological) sections of the thoracic outlet.
*Section Sports Medicine, University of Pretoria, Pretoria, South Africa;
†AstraZeneca Pharmaceuticals, Johannesburg, South Africa;
‡Netcare Union Hospital, Johannesburg, South Africa; and
§Department of Surgery, University of Witwatersrand, Johannesburg, South Africa.
Corresponding Author: Robert M. Collins, MBBCh, MSc, Section Sports Medicine, University of Pretoria, PO Box 3264, Houghton, Johannesburg 2014, South Africa (firstname.lastname@example.org).
The authors report no conflicts of interest.
Received February 05, 2013
Accepted July 30, 2013