Azygos lobe of the lung and its important clinical. The azygos fissure is typically visible on chest radiography as a right paramediastinal supernumerary line in projection of the right lung apex. Compare the radiographic findings before c and after d therapy. An accessory fissure not due to anomalous course of azygos vein in the right upper lobe is rarely documented. The azygos lobe is a normal variant that is found in 1% of anatomic specimens and. In order that the progress of the left vena azygos towards the subclavian i. An unusual accessory fissure in the right upper lobe mahe. Current challenges in thoracic surgery, 2019 e aege oa ge g eee urr hall thorac surg 211 oog12212 page 3 of 4 taken to the or for vats right lung reduction with a plan to resect the azygos lobe and most of the apical segment. Ihe azygos lobe is a now commonly recog nized congenital anomaly of the upper lobe of the lung.
The azygos lobe is a rare anatomical variant, most often encountered in the right lung. In this article, we describe six new cases of migrating azygos vein, one of them with a vanishing azygos lobe, and attempt to explain the etiologic factors that contribute to migration of the vein. The azygos lobe is a congenital variant which has been described in 1% of subjects and in about 0. Primary lung cancer in the azygos lobe european journal. The right azygos lobe is a rare anatomical variant of the upper lung lobe that can be misdiagnosed as a neoplasm, a lung. At the risk of semantic nitpicking i would point out that there is no such entity as an azygos lobe and that lobar anatomy is defined primarily on the basis of bronchial anatomy. Sequential unilateral lung volume reduction surgery in the. Clinically, the azygos lobe has been accepted as a normal variation that can simulate various diseases. Results showed that the prevalence of the right azygos lobe in the study sample was 0. To our knowledge, there are no reported cases of vanishing azygos lobe. In human anatomy, an azygos lobe is a normal anatomical variation of the upper lobe of the right lung. Azygos lobe results in a typical appearance on plain radiographs and ct that is easily recognized and produces a characteristic alteration in normal mediastinal anatomy. The azygos lobe, also commonly referred to as an accessory lobe of the azygos vein, is located at the apicomedial portion of the right lung and is separated from the remainder of the upper lobe by a fissure.
An azygos lobe and fissure were also found fig 1, black arrow. 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. The azygos, hemiazygos and accessory hemiazygos veins orig. In other cases, diffuse pulmonary pathologies respect the azygos lobe fig. 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. Isolation of the azygos lobe was achieved with little. The 3dimensional reconstruction of computed tomography demonstrates an azygos lobe arrowheads, an azygos fissure arrows, and. In this paper we describe the normal appearance of the azygos lobe on conventional radiography and ct, presenting variants that may simulate pathology on the chest radiograph.
A pulmonary azygos lobe encountered during thoracotomy for. Recurrent hemoptysis a complication associated with an. Mar 01, 2000 the azygos lobe is a normal variant that is found in 1% of anatomic specimens and on about 0. Jan 01, 2018 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. In conclusion, the azygos lobe is a rare anomaly in the south african cadaveric population. It usually has no significant clinical implications. Azygos lymph node enlargement is usually an indication of advanced bronchogenic carcinoma, although it may occur in benign pulmonary disease. It occurs 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 pleural layers that entrap a portion of the right upper lobe. Sorry, we are unable to provide the full text but you may find it at the following locations. Azygos lobe which appears in the inner surface of the right lung apex is a rare venous anomaly of the lung. The history of the development of knowledge of the azygos lobe, from its first description by wrisberg in 1778, is fully given as well as its embryologic development, dependent on a higher entrance than normally of the azygos vein into the vena cava, which.
The history of the development of knowledge of the azygos lobe, from its first description by wrisberg in 1778, is fully given as well as its embryologic development, dependent on a higher entrance than normally of the azygos vein into the vena cava, which forces the pulmonary buds to grow around instead of pushing the vein to one side. Thoracoscopic resection was performed for a 53yearold female with solitary pulmonary nodule at the azygos lobe a, b. Primary lung cancer in the azygos lobe european journal of. The lobe of the azygos vein rsna publications online home. This case suggests that the presence of an azygos lobe can be missed on chest xray when a pneumothorax occurs in a patient with an azygos lobe. An autopsy photograph of azygos lobe located cranially in the right upper lung lobe. Because of the clinical importance and rare occurrence, this.
This is relatively unusual, as most elements of anatomy reflect bilateral symmetry. This variant is the result of a failure in the migration of the posterior cardinal vein, a precursor of the azygos vein, from the thoracic wall to its normal location in the tracheobronchial angle. An azygos lobe is a rare congenital variant of the right lung, usually diagnosed as an incidental finding. We analyzed a total of 1709 axial thoracic multidetector computed tomography ct images. Its pathogenesis is discussed, as are the characteristic xray features that enable an accurate diagnosis. Embryologically, it arises from an anomalous lateral course of the azygos vein, in a pleural septum within the apical segment of the right upper lobe or in other words an azygos lobe is formed when the right posterior cardinal vein, one of the precursors of. Understanding the structure of the azygos lobe is important. Intrapulmonary right brachiocephalic vein associated with. Any information contained in this pdf file is automatically generated from. The azygos lobe forms when the right posterior cardinal vein, the precursor of the upper thoracic segment of the azygos vein, fails to migrate over the apex of the right lung to its normal medial position in the mediastinum 5. So, the detection of this anomaly and clarification of its precise. Download as pdf print show related cases notify admin. Intraoperatively, the azygos lobe was pulled out from behind the pleural folds c, which form a mesenterylike structure, containing the azygos vein in its lowest portion d.
The right azygos lobe is a well recognized entity seen in about 0. The azygos lobe is a congenital variant and occurs in the intrauterine period with the azygos vein passing through the anterior. The azygos lobe the journal of thoracic and cardiovascular. Azygos lobe accessory lobe of the azygos vein lobus azygos. The presence of an azygos lobe al may make it difficult or even impossible to use videoassisted thoracic sympathectomy if the surgeon is unprepared to deal with this anatomical anomaly. The azygos lobe is a rare anomaly that developmentally arises when the right posterior cardinal vein. Seven hyperhidrosis patients with an al from a total of 1,876 individuals who underwent videoassisted thoracic sympathectomy are presented. The azygos lobe al is a normal variant that is found in 1% of anatomical specimens and on about 0. It also incidentally revealed an azygos fissure along with an azygos lobe on the right side fig.
The azygos lobe intrudes into the pretracheal and retrotracheal mediastinum contacting the anterior wall of the. We report such an accessory fissure between the apical and posterior segments of right upper lobe through computed tomographic ct scan of chest in a case of chronic obstructive pulmonary disease. Azygos vein enlargement on the chest film jama jama network. 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. This arch of the azygos vein arcus venae azygos is an important anatomic landmark. A contrast enhanced ct scan study of chest is useful to determine whether the accessory. We describe the normal appearance of the azygos lobe on plain radiography and ct. An azygos lobe of the lung is a rare congenital venous malformation. Often it is found in conjunction with enlargement of hilar and other mediastinal lymph nodes. Four patients without other evidence of underlying disease were evaluated. Several findings are presented that, to our knowledge, have not been previously reported, such as the inferior prolongation of the fissure, the apparent intrapulmonary path of the right brachiocephalic vein and superior vena cava seen on the anteroposterior chest radiograph, and the visible fissure on. In cases of tef, the azygos vein course is surgically signi. Left azygos lobe has been reported as well, but it is extremely rare 7,8. The azygos lobe is a congenital variant with an incidence of 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 with two pleural layers that invaginate into the upper portion of the right. Various etiologies have been described in the literature for the migration of the azygos vein. It is usually detected using a chest xray, but computed tomography can also be used in selected cases for advanced examination and differential diagnosis. A 60yearold female patient underwent a ct examination for presurgical staging. Indeed the azygos lobe is not strictly a lung lobe 3. However, on chest roentgenograms, this anomaly may appear to be present if there are any other pathological conditions. In patients with this anomaly, the azygos arch is located more cephalad than normal, at, near, or above the junction of the brachiocephalic veins. It is usually asymptomatic and does not require a specific treatment, but it should be kept in mind in the differential diagnosis of lesions in the lungs and should be considered for the presence of cardiopulmonary pathology that may accompany.
Left azygos lobe is much rarer than right azygos lobe, but cases have been reported. Azygos lobe accessory lobe of the azygos vein lobus. Spontaneous pneumothorax and a coexistent azygos lobe. In the present study, an azygos lobe was observed on the right lung of a. An azygos lobe is an accessory lobe of the lung that may occasionally be confused with a pathological process such as a bulla, lung abscess or neoplasm. Fortunately no adhesions were encountered in relation to the previous thoracostomy tube and the azygos lobe with associated laterally displaced azygos vein were present as expected. Radiographic appearance the azygos lobe is a normal variant that is found the azygos lobe is usually well seen on the chest in 1% of anatomic specimens and on about 0. The migrating azygos vein has been described in isolated case reports. Discussionearly authors thought that the azygos lobe was a supernumerary lobe, but in 1870 cleland stated that this was a partial segmentation of a normal right upper lobe by an abnormally placed azygos vein in foster carter 1946. A pulmonary azygos lobe is usually an incidental finding in cadaver dissections and chest radiography. 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. On chest radiographs, azygos fissure azygos fissure in figure 1 is visible as a fine. A rare cause of right paratracheal opacity sciencedirect.
None of the intern doctors or surgery residents identi. Azygos lobe in a south african cadaveric population rauf. We present an unusual case of partial anomalous venous drainage in which the vein of the right upper lobe drains into the superior vena cava, together with the azygos vein. Computed tomography proved more reliable than plain radiography in the diagnosis of left azygos lobe in a 10yearold girl. The surgical technique and clinical evolution are described. The shadow was thought to be due to one of several conditions, namely, azygos lobe, pleuritic thickening around the apex, substernal thyroid, aneurysm, or local pneumonic consolidation. Its etiology is related to a defect of the migration of the azygos vein during the embryonic development. Pdf prevalence of an azygos lobe using thoracic computed. The author could find only 11 cases that have been previously reported in the world literature. An azygos lobe is a congenital variation in the apex of the right lung 1,2. The accessory lobe of the azygos vein br med j 1931. Its bronchial supply is derived from a branch of the upper lobe bronchus and not as a separate branch from the right main bronchus. A rare case of anomalous venous drainage of the right upper lobe. An azygos lobe is observed in highresolution computed tomography images by 1.
This septum consists of both visceral and parietal layers of the pleura, and is so disposed that its outer surface is convex and the lower free margin, which contains between its layers the vena azygos, is arched. 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. An azygos lobe is found in 1% of anatomical specimens 2 and is twice as common in males as females 3 embryology. The diagnosis is usually made incidentally on chest xray, as in our patient, and no treatment is required in most cases. The azygos lobe is a normal variant that is found in 1% of anatomic specimens and on about 0. We describe the signs that allow identification of such variants and the role of ct in explaining the findings and excluding a pathological process. The necropsy demonstrated this to be due to an azygos lobe fig. Cureus a rare case of an azygos lobe in the right lung of a. In this paper we describe the normal appearance of the azygos lobe on conventional. A cadaver with azygos lobe and its clinical significance. Computed tomography proved more reliable than plain radiography in the diagnosis of left azygos lobe in. 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.
Observations on the morphology of the azygos lobe showed that it was rectangular n 3 and triangular n 1 in shape with smooth margins. Cureus a rare case of an azygos lobe in the right lung. Pdf azygos lobe al is a rare normal anatomic variant of the lung with a frequent location at the right upper lobe. The pathology proved primary lung adenocarcinoma e, f. Here, we describe a rare case of an azygos lobe of the right lung, diagnosed incidentally on a computed tomography ct scan in a 40yearold male patient who presented with chest pain, shortness of. The azygos lobe is therefore not a true lobe like the cardiac and posterior middle lobes. Isolated azygos lymph node enlargement is unusual and demands tissue diagnosis. Prevalence of an azygos lobe using thoracic computed. Azygos lymph node enlargement as initial manifestation of. Although an azygos lobe is a rare anomaly of the lung, its radiological appearance has been well defined.
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