link
Bookmarks
Accessory Azygos Fissure
Sherief H. Garrana, MD
To access 4,300 diagnoses written by the world's leading experts in radiology, please log in or subscribe.Subscribe
0
4
0
0

KEY FACTS

  • Terminology

    • Imaging

      • Top Differential Diagnoses

        • Pathology

          • Clinical Issues

            • Diagnostic Checklist

              TERMINOLOGY

              • Synonyms

                • Azygos fissure
              • Definitions

                • Anomalous intrapulmonary course of azygos vein that creates accessory fissure
                  • Includes 4 layers of non-fused parietal and visceral pleura (mesoazygos) invaginated into medial right upper lobe (RUL)
                  • Vertical or curved oblique course of fissure
                  • Teardrop-shaped lower margin contains azygos vein
                  • Trigone
                    • Cranial aspect of fissure (triangular shape); determines size of lung medial to fissure
                    • Included lung shape classified based on trigone position
                      • Type A: Trigone located in lateral aspect of pulmonary apex
                      • Type B: Trigone located at mid point of apex; fissure is relatively vertically oriented
                      • Type C: Trigone located medially; fissure curves toward mediastinum
                    • Fissure length varies with type: Longer in type A, shorter in types B and C
                • Accessory fissure of variable size borders medial aspect of RUL

              IMAGING

              • Imaging Recommendations

                • Radiographic Findings

                  • CT Findings

                    DIFFERENTIAL DIAGNOSIS

                      PATHOLOGY

                      • General Features

                        CLINICAL ISSUES

                        • Presentation

                          • Demographics

                            DIAGNOSTIC CHECKLIST

                            • Image Interpretation Pearls

                              Selected References

                              1. Bostanci K et al: Variations in pulmonary fissural anatomy: a medicolegal autopsy study of 256 cases. ANZ J Surg. 90(4):608-11, 2020
                              2. Semionov A et al: Migration of the azygos vein from the azygos fissure to the mediastinum. Radiol Case Rep. 14(6):763-5, 2019
                              3. Taydas O et al: Reentrance of azygos vein into azygos fissure after pneumothorax. Eurasian J Med. 49(1):62-3, 2017
                              4. Suwatanapongched T et al: Visibility and variability of pleural fissures on normal digital chest radiographs of 1,000 healthy adults. Jpn J Radiol. 33(4):201-9, 2015
                              5. Lenoir V et al: The empty azygos fissure. J Radiol Case Rep. 7(4):10-5, 2013
                              6. Villanueva A et al: Migrating azygos vein and vanishing azygos lobe: MDCT findings. AJR Am J Roentgenol. 194(3):599-603, 2010
                              7. Maldjian PD et al: The empty azygos fissure: sign of an escaped azygos vein. J Thorac Imaging. 23(1):54-6, 2008
                              8. Hayashi K et al: Radiographic and CT appearances of the major fissures. Radiographics. 21(4):861-74, 2001
                              9. Shin MS et al: Clinical significance of azygos vein enlargement: radiographic recognition and etiologic analysis. Clin Imaging. 23(4):236-40, 1999
                              10. Caceres J et al: The azygos lobe: normal variants that may simulate disease. Eur J Radiol. 27(1):15-20, 1998
                              Related Anatomy
                              Loading...
                              Related Differential Diagnoses
                              Loading...
                              References
                              Tables

                              Tables

                              KEY FACTS

                              • Terminology

                                • Imaging

                                  • Top Differential Diagnoses

                                    • Pathology

                                      • Clinical Issues

                                        • Diagnostic Checklist

                                          TERMINOLOGY

                                          • Synonyms

                                            • Azygos fissure
                                          • Definitions

                                            • Anomalous intrapulmonary course of azygos vein that creates accessory fissure
                                              • Includes 4 layers of non-fused parietal and visceral pleura (mesoazygos) invaginated into medial right upper lobe (RUL)
                                              • Vertical or curved oblique course of fissure
                                              • Teardrop-shaped lower margin contains azygos vein
                                              • Trigone
                                                • Cranial aspect of fissure (triangular shape); determines size of lung medial to fissure
                                                • Included lung shape classified based on trigone position
                                                  • Type A: Trigone located in lateral aspect of pulmonary apex
                                                  • Type B: Trigone located at mid point of apex; fissure is relatively vertically oriented
                                                  • Type C: Trigone located medially; fissure curves toward mediastinum
                                                • Fissure length varies with type: Longer in type A, shorter in types B and C
                                            • Accessory fissure of variable size borders medial aspect of RUL

                                          IMAGING

                                          • Imaging Recommendations

                                            • Radiographic Findings

                                              • CT Findings

                                                DIFFERENTIAL DIAGNOSIS

                                                  PATHOLOGY

                                                  • General Features

                                                    CLINICAL ISSUES

                                                    • Presentation

                                                      • Demographics

                                                        DIAGNOSTIC CHECKLIST

                                                        • Image Interpretation Pearls

                                                          Selected References

                                                          1. Bostanci K et al: Variations in pulmonary fissural anatomy: a medicolegal autopsy study of 256 cases. ANZ J Surg. 90(4):608-11, 2020
                                                          2. Semionov A et al: Migration of the azygos vein from the azygos fissure to the mediastinum. Radiol Case Rep. 14(6):763-5, 2019
                                                          3. Taydas O et al: Reentrance of azygos vein into azygos fissure after pneumothorax. Eurasian J Med. 49(1):62-3, 2017
                                                          4. Suwatanapongched T et al: Visibility and variability of pleural fissures on normal digital chest radiographs of 1,000 healthy adults. Jpn J Radiol. 33(4):201-9, 2015
                                                          5. Lenoir V et al: The empty azygos fissure. J Radiol Case Rep. 7(4):10-5, 2013
                                                          6. Villanueva A et al: Migrating azygos vein and vanishing azygos lobe: MDCT findings. AJR Am J Roentgenol. 194(3):599-603, 2010
                                                          7. Maldjian PD et al: The empty azygos fissure: sign of an escaped azygos vein. J Thorac Imaging. 23(1):54-6, 2008
                                                          8. Hayashi K et al: Radiographic and CT appearances of the major fissures. Radiographics. 21(4):861-74, 2001
                                                          9. Shin MS et al: Clinical significance of azygos vein enlargement: radiographic recognition and etiologic analysis. Clin Imaging. 23(4):236-40, 1999
                                                          10. Caceres J et al: The azygos lobe: normal variants that may simulate disease. Eur J Radiol. 27(1):15-20, 1998