Azygos Lobe: Prevalence of an Anatomical Variant and Its Recognition among Postgraduate Physicians

Abstract

The right azygos lobe is a rare anatomical variant of the upper lung lobe that can be misdiagnosed as a neoplasm, a lung abscess, or a bulla. The aim of this study was to assess the prevalence of right azygos lobe and to evaluate the ability of postgraduate doctors to correctly identify right azygos lobe. We analyzed a total of 1709 axial thoracic multi-detector computed tomography (CT) images for the presence of an azygos lobe. Additionally, a paper-based survey was distributed among a sample of intern doctors and radiology and surgery residents, asking them to identify the right azygos lobe in a CT image and in an anatomy figure. Results showed that the prevalence of the right azygos lobe in the study sample was 0.88%. Men have more right azygos lobes than women. None of the intern doctors or surgery residents identified the right azygos lobe correctly, whereas more than half (57.1%) of the radiology residents did. Most of the incorrect answers about the CT scan were related to the bronchi (25.0%). The apex of the lung (17.7%) and the superior vena cava (17.7%) were the most common incorrect answers about the anatomy figure. In conclusion, the prevalence of the right azygos lobe in the current study is within the range of previously published literature. More education should be given for the identification of the right azygos lobe during anatomy and clinical teaching.

The prevalence of the azygos lobe: A meta‐analysis of 1,033,083 subjects

“…The population was not reported in one study (3500 subjects, 0.3%). Gender-based prevalence was calculated from six studies (Al-Mnayyis et al, 2020;C aceres et al, 1993;Clive, 1943;Ichikawa et al, 2008;Özdemir et al, 2016;Rauf et al, 2012), in which 2527and 32,908 were identified as male and female, respectively. Six diagnostic tools were used to detect the AL including X-rays (47 studies), CT (16 studies), dissection (11 studies), surgical identification (seven studies), MRI (five studies), and analysis of preadmission records (one study) (Table 1).…”

Toraks Bilgisayarlı Tomografisinde Tesadüfen Saptanan Nadir Bir Anatomik Varyasyon: Azigos Lobu

“…In this study, the prevalence was found to be 1.39% in women and 1.64% in men. In the study conducted by Al-Mnayyis et al with 1709 CT scans, the prevalence of the azygos lobe was found to be 1.01%, 0.62%, and 0.88% in men, women, and all cases, respectively [13]. In the study conducted by Perincek et al, the frequency of azygos lobes was found to be 1.09%, and the incidence was found to be higher in men than in women (approximately 56% and 44%, respectively) [8].…”

A case of tuberculosis of the rare azygos lobe of the right lung

“…The azygos lobe is a rare anatomical variant seen in the upper lobe of right lung [1,2]. It is typically seen in the medial portion of the upper lobe of right lung [1][2][3].…”

“…The azygos lobe is a rare anatomical variant seen in the upper lobe of right lung [1,2]. It is typically seen in the medial portion of the upper lobe of right lung [1][2][3]. It is separated from the rest of the right upper lobe by an accessory fissure, known as the azygos fissure [1,2].…”

“…It is typically seen in the medial portion of the upper lobe of right lung [1][2][3]. It is separated from the rest of the right upper lobe by an accessory fissure, known as the azygos fissure [1,2]. It occurs during embryological development due to the failure of posterior cardinal vein to migrate supero-medially [1,2,4].…”