Cervical rib which resembles original thoracic rib presenting with thoracic outlet syndrome (TOS): Literature review with a case report

Abstract

The cervical rib (CR) is a rare skeletal anomaly, which generally articulated with the transverse process of the 7th cervical vertebra, and commonly lead to compression of neurovascular structures in the region of the thoracic outlet. CRs are divided into 2 classes as complete and incomplete forms. A clarifying description of the so-called complete CR form has not been found with sufficient information in the literature. We aimed to present a novel case of an anomalous, supernumerary, extra, or additional rib which arises from the seventh cervical vertebra. We present the case of a 23-year-old female who presented with a mass described as slowgrowing since her childhood in the supraclavicular region. The patient complained of pain, numbness, weakness, and difficulty in lifting her right arm, which increased gradually over in the last 6 months. Physical examination revealed findings of thoracic outlet syndrome (TOS). Radiographic analysis demonstrated a huge cervical rib, which resembles the size of a real thoracic rib. The cervical rib was completely resected through the supraclavicular approach. There is not enough data in theliterature about different morphologic properties of CRs. It is presented with 3-D CT images before and after surgical resection. The final version of the transformation of C7 transverse process to an original Thoracic Rib is shown. As a result, the following question presented, can it be called a Zeroth Rib?.