On chest radiograph, azygos lobe can be seen as a curvilinear line of the right apex separating the apical right upper lung segment. The azygos lobe is a congenital variant with an incidence of about 0. An azygos lobe and fissure were also found fig 1, black arrow. The azygos arch was found dangling in the free inferior border of the mesoazygos.
The azygos vein had an abnormal anterior loop and entered the anterior surface of the right upper lobe. Embryologically, it arises from an anomalous lateral course of the azygos vein 1 in a pleural. An azygos lobe is one of, if not the most commmonest, anatomical variants observed on plain chest xray. A rounded projection, especially a rounded, projecting anatomical part. Azygos definition at, a free online dictionary with pronunciation, synonyms and translation. A small lobe sometimes found on the upper part of the right lung, formed by an infolding of the pleura and separated from the rest of the upper lobe by a deep groove lodging the azygos vein. An autopsy photograph of azygos lobe located cranially in the right upper lung lobe. Understanding the structure of the azygos lobe is important. The azygos arch was found dangling in the free inferior border of the. An azygos lobe is created when a laterally displaced azygos vein makes a deep pleural fissure into the apical segment of the right upper lobe during embryological development. Instead of an inverted commalike line alone, the area corresponding to the usual position of the azygos lobe was found to consist of a uniformly dense shadow suggesting consolidation, but which proved upon examination to be free from any abnormal changes. The woman had developed kyphosis angled at the level.
The patient had undergone interstitial brachytherapy for a tumor of the right upper lung, with implantation of palladium103 seeds that migrated and occluded the arteries of this lung segment. The azygos lobe is therefore not a true lobe like the cardiac and posterior middle lobes. In human anatomy, an azygos lobe is a normal anatomical variation of the upper lobe of the right lung. Spontaneous pneumothorax and a coexistent azygos lobe. A cadaver with azygos lobe and its clinical significance. However, on chest roentgenograms, this anomaly may appear to be present if there are any other pathological conditions. Its counterparts on the left side are the hemiazygos and accessory hemiazygos veins. Azygos vein enlargement on the chest film jama jama. A chest roentgenogram showed a shadow in the left lower lobe and a lobus venae azygos. Pdf azygos lobe al is a rare normal anatomic variant of the lung with a frequent location at the right upper lobe.
A 25yearold man with a previously identified azygos lobe was admitted to. Congenital and acquired abnormalities of the azygos vein can affect its size and position. All patients had repeated episodes of cough, vomiting, and a short mesoazygos. The azygos fissure white arrows demarcates the lateral boundary of the azygos lobe, part of the right upper lobe.
Azygos lobe in a south african cadaveric population. Learning radiology central, venous, catheter, azygos, vein. The azygos lobe azygos lobe in figures 1 and and2 2 is a uncommon anomaly that is found in 1% of anatomic specimens, 1 on about 0. An azygos lobe forms when the right posterior cardinal vein, one of the precursors of the azygos vein, fails to migrate over the apex of the lung and penetrates it instead, carrying along two pleural layers that invaginates into the upper portion of the right upper. A rare case of an azygos lobe in the right lung of a 40yearold. Pdf migrating azygos vein and vanishing azygos lobe.
Objective the purpose of this study was to describe six cases of migrating azygos vein and to explain the etiologic factors that contribute to the migration. Pdf on jul 1, 20, takako mikami and others published azygos lobe find, read and cite all the research you need on researchgate. Although an azygos lobe is a rare anomaly of the lung, its radiological appearance has been well defined. Azygos lobe definition of azygos lobe by medical dictionary.
A routine anteroposterior chest roentgenogram fig 1 showed marked enlargement of the azygos vein 20 mm in width, white arrows. Excerpt the peculiar inverted commalike shadow occasionally seen in the right upper lobe remained a puzzle to roentgenologists until the postmortem studies of bendick and wessler 1 determined the exact nature of this anomaly. Accepting aebys definition, the authors hold that a lobe is that part of the lung extending to the pleura and depending on one or more primary bronchi and separated from other lobes by a pulmonary fissure. There is no clinical significance and no treatment is required. Media in category human anatomy, azygos lobe the following 22 files are in this category, out of 22 total. The lungs are normally divided into five lobes by three main fissures.
Pdf the azygos lobe is a rare anomaly in bronchopulmonary. These images have typical appearance of azygos lobe, fissure and vein. Normally, the thoracic portion of the azygos vein is derived from the right posterior cardinal vein and arches over the apex of the right lung, draining towards the superior vena cava. The tearshaper azygos vein is seen at the base of the fissure red arrow. We report a case of a migrating azygos vein developing after an abrupt spinal deformity adjacent to the azygos arch. In contrast to other accessory lobes, the azygos lobe does not correspond to a distinct anatomical bronchopulmonary. Embryologically the azygos lobe is a part of the right upper lobe and its bronchial and arterial supplies arise from the apical or posterior segments of the right upper lobe 5,6. Recognition and accurate characterization of abnormalities of the azygos vein on imaging studies is critical to facilitate prompt diagnosis and direct workup. Azygos lobe is formed when a displaced right posterior cardinal vein penetrates. In human anatomy, an azygos lobe is a normal anatomical variation of the upper lobe of the. Clinically, the azygos lobe has been accepted as a normal variation that can simulate various diseases. Left azygos lobe has been reported as well, but it is extremely rare 7,8. Lobe of azygos vein definition of lobe of azygos vein by. Heinrich wrisberg first recognized it during a postmortem exam in 1877 and it was first described on the chest radiograph in 1923 1,3.
We use cookies to give you the best possible experience on our website. Alteration of contrast material flow dynamics of the azygos vein on computed tomography can be an indication of superior vena cava obstruction. As an anatomical variation in 12% of the population, the arch can be displaced laterally, thereby creating a pleural septum separating an azygos lobe from the upper lobe of the right lung. Occasionally, invaginations of the visceral pleura create accessory fissures that separate individual bronchopulmonary segments into accessory lobes. Azygos lobe al is a rare normal anatomic variant of the lung with a. Once again, during the operation for primary repair of the esophageal atresia, difficulties arose in reflecting the pleura. The azygos lobe is a rare anatomical variant, most often encountered in the right lung. Azygos lobe and partial eventration of diaphragm raghu s. Azygos lobe definition of azygos lobe by the free dictionary. This video demonstrate the presence of a azygos lobe in a patient submitted to a thoracotomy for lung cancer. The azygos lobe is seen at the right lung apex with the azygos vein lying on its lowermost. A pulmonary azygos lobe is usually an incidental finding in cadaver dissections and chest radiography. Extensive evaluation revealed a squamous cell carcinoma of the left lower lobe, and lobectomy was performed.
An azygos lobe is found in 1% of anatomical specimens 2 and is twice as common in males than females 3 embryology. Six patients with migrating azygos vein were studied by mdct before and after migration. A woman with a previously identified azygos lobe had a followup chest computed tomography that demonstrated the azygos vein dislocated medially to the fissure in its usual mediastinal position. Cureus a rare case of an azygos lobe in the right lung. The peculiar inverted commalike shadow occasionally seen in the right upper lobe remained a puzzle to roentgenologists until the postmortem studies of. Its bronchial supply is derived from a branch of the upper lobe bronchus and not as a separate branch from the right main bronchus. The azygos lobe azygos lobe in figures 1 and 2 is a uncommon anomaly that is found in 1% of anatomic specimens, 1 on about 0. It is due to invagination of the azygos vein and pleura during foetal development. In approximately 2% of the population, the arch of the azygos vein which courses over the right main bronchus, can be part of a pleural septum producing the azygos lobe, which is separate from the right upper lobe. This system consists of the azygos vein and its two main tributaries. The azygos lobe is covered by this veil of pleura which contains the arch of the azygos vein in its free inferior edge.
Azygos lobe generally means accessory lobe or supernumerary lobe of lung. This arch of the azygos vein arcus venae azygos is an important anatomic landmark. The azygos vein, in this case, is found passing along the bottom of the fissure and is suspended from the thoracic wall through a fold of the. Azygos definition of azygos by the free dictionary. On chest radiographs, azygos fissure azygos fissure in figure 1 is visible as. Azygos lobe is a rare congenital variation usually located in the right lung and more common in males. Azygos lobe article about azygos lobe by the free dictionary. Pdf azygos lobe al is a rare normal anatomic variant of the lung.