Figure 1
Teaching Case
SectionChest imaging
Case TypeClinical Cases
AuthorsGasim Ahmed, Aneeq Ahmed, Sami Nour, Mudathir Mohamed
Connected authors
17 years, male
A 17-year-old male patient with no past medical history presented with a 24-hour history chest pain radiating to the anterior aspect of the neck. Physical examination revealed normal vital signs. Swelling and crepitus involving the bilateral anterolateral aspects of the neck and the submandibular fossae were noted.
Primary spontaneous pneumomediastinum
Medial pneumothorax
Pneumopericardium
Pneumoperitoneum
A chest X-ray, in addition to pneumomediastinum and pneumopericardium, revealed supraclavicular, para-tracheal and infrahyoid emphysema. A computed tomography of the thorax showed pneumopericardium with air dissecting from the diaphragm crus through the posterior, middle, anterior and superior mediastinum. There was also diffuse bilateral supra-clavicular, pre-tracheal, carotid, posterior cervical, retro-pharyngeal space and bilateral axillary surgical emphysema. No parenchymal lung disease was detected. A water soluble contrast fluoroscopic examination of the oesophagus revealed no evidence of extravasation or leak of contrast.
Background:
Spontaneous pneumomediastinum is the presence of air within mediastinum structures. The condition is considered rare with a reported incidence of 1/42, 000 of admissions [1]. Spontaneous pneumomediastinum has been recognised at least since 1819 but it was Hamman who initially reported a case series in 1937 and revisited the disease in 1939 [1-3]. Physiopathology is related to alveolar rupture and gas dissection through the bronchovascular fascia followed by pulmonary interstitial dissemination to the mediastinum as described by Macklin in 1939 [4].
Clinical Perspective:
Chest pain, the predominant presenting feature affecting 55% of patients, is typically retrosternal and may have a pleuritic character. Dyspnoea, cough and neck pain occur in 40%, 32%, and 17% of patients, respectively [5, 6]. Subcutaneous emphysema may complicate 60% of cases [7, 8]. Hamman's sign, a crunching, rasping sound, synchronous with systole may be present in 50% of patients [3, 8]. The disease can be either primary or secondary to trauma. Other triggers include coughing, balloon inflation, aviation, vomiting, and oesophageal rupture [9, 10, 11, 12]. The role of cocaine has also been described [13]. In the paediatric cohort, acute asthma exacerbation [7, 14] and lower respiratory tract infections are the predominant causes [7, 14-16]. In 21% of cases no cause is found [17].
Radiological Perspective:
Radiologically, a number of signs such as the Naclerio's V sign, V sign at confluence of brachiocephalic veins and ring-around-the-artery sign can be observed as lucent streaks of gas outline mediastinal structures [18]. Additional signs include tubular artery, double bronchial wall and haystack signs. Other abnormalities such as pneumothorax, pleural effusion (which may indicate oesophageal rupture), and signs of chronic lung disease may be noted. Computed tomography is usually not indicated unless in patients with underlying lung disease. Contrast oesophagography is helpful if oesophageal rupture is suspected as a cause.
Outcome:
The management of uncomplicated spontaneous pneumomediastinum is conservative and includes analgesia, rest, oxygen, and avoidance of manoeuvres that increase pulmonary pressure. Although evidence is limited, air travel is usually permitted two weeks after radiographic resolution. In cases with complications such as pneumothorax, management should target the specific complication. The natural history of the disease is benign. Although approximately 5% of cases may recur, the outcome is favarouble [19].
Take Home Message:
Spontaneous pneumomediastinum is a rare, generally benign cause of chest pain.
Radiologically, streaks of air are observed outlining mediastinal structures.
In one fifths of cases no trigger is identified.
Spontaneous pneumomediastinum is the presence of air within mediastinum structures. The condition is considered rare with a reported incidence of 1/42, 000 of admissions [1]. Spontaneous pneumomediastinum has been recognised at least since 1819 but it was Hamman who initially reported a case series in 1937 and revisited the disease in 1939 [1-3]. Physiopathology is related to alveolar rupture and gas dissection through the bronchovascular fascia followed by pulmonary interstitial dissemination to the mediastinum as described by Macklin in 1939 [4].
Clinical Perspective:
Chest pain, the predominant presenting feature affecting 55% of patients, is typically retrosternal and may have a pleuritic character. Dyspnoea, cough and neck pain occur in 40%, 32%, and 17% of patients, respectively [5, 6]. Subcutaneous emphysema may complicate 60% of cases [7, 8]. Hamman's sign, a crunching, rasping sound, synchronous with systole may be present in 50% of patients [3, 8]. The disease can be either primary or secondary to trauma. Other triggers include coughing, balloon inflation, aviation, vomiting, and oesophageal rupture [9, 10, 11, 12]. The role of cocaine has also been described [13]. In the paediatric cohort, acute asthma exacerbation [7, 14] and lower respiratory tract infections are the predominant causes [7, 14-16]. In 21% of cases no cause is found [17].
Radiological Perspective:
Radiologically, a number of signs such as the Naclerio's V sign, V sign at confluence of brachiocephalic veins and ring-around-the-artery sign can be observed as lucent streaks of gas outline mediastinal structures [18]. Additional signs include tubular artery, double bronchial wall and haystack signs. Other abnormalities such as pneumothorax, pleural effusion (which may indicate oesophageal rupture), and signs of chronic lung disease may be noted. Computed tomography is usually not indicated unless in patients with underlying lung disease. Contrast oesophagography is helpful if oesophageal rupture is suspected as a cause.
Outcome:
The management of uncomplicated spontaneous pneumomediastinum is conservative and includes analgesia, rest, oxygen, and avoidance of manoeuvres that increase pulmonary pressure. Although evidence is limited, air travel is usually permitted two weeks after radiographic resolution. In cases with complications such as pneumothorax, management should target the specific complication. The natural history of the disease is benign. Although approximately 5% of cases may recur, the outcome is favarouble [19].
Take Home Message:
Spontaneous pneumomediastinum is a rare, generally benign cause of chest pain.
Radiologically, streaks of air are observed outlining mediastinal structures.
In one fifths of cases no trigger is identified.
References
[1] Bodey G. Medical mediastinal emphysema. Ann Intern Med. 1961; 54:46. DOI: 10.7326/0003-4819-54-1-46
[2] Hamman L. Spontaneous Interstitial Emphysema of the Lungs. Tr. A. Am. Physicians 52:311-319, 1937
[3] Hamman L. Spontaneous Mediastinal Emphysema. Bull. Johns Hopkins Hosp. 44:11939
[4] Macklin CC. (1939) Transport of air along sheaths of pulmonic blood vessels from alveoli to mediastinum: clinical implications. Arch Intern Med (Chic). 1939;64(5):913-926. doi:10.1001/archinte.1939.00190050019003
[5] Zachariah S, Gharahbaghian L, Perera P, Joshi N. Spontaneous pneumomediastinum on bedside ultrasound: case report and review of the literature. West J Emerg Med. 2015;16(2):321-4 (PMID: 25834681)
[6] Chalumeau M, Le Clainche L, Sayeg N, Sannier N, Michel JL, Marianowski R, et al. Spontaneous pneumomediastinum in children. Pediatr Pulmonol. 2001;31(1):67-75 (PMID: 11180677)
[7] Stack AM, Caputo GL. Pneumomediastinum in childhood asthma. Pediatr Emerg Care. 1996;12(2):98-101 (PMID: 8859917)
[8] Sahni S, Verma S, Grullon J, Esquire A, Patel P, Talwar A. Spontaneous pneumomediastinum: time for consensus. N Am J Med Sci. 2013;5(8):460-4 (PMID: 24083220)
[9] Mumford AD, Ashkan K, Elborn S. Clinically significant pulmonary barotrauma after inflation of party balloons. BMJ. 1996;313(7072):1619 (PMID: 8991010)
[10] Grossman A, Romem A, Azaria B, Goldstein L, Barenboim E. Pneumomediastinum in student aviators: 10 cases with return to flying duty. Aviat Space Environ Med. 2005;76(1):63-5 (PMID: 15672989)
[11] Forshaw MJ, Khan AZ, Strauss DC, Botha AJ, Mason RC. Vomiting-induced pneumomediastinum and subcutaneous emphysema does not always indicate Boerhaave's syndrome: report of six cases. Surg Today. 2007;37(10):888-92 (PMID: 17879041)
[12] Engum SA, Grosfeld JL, West KW, Rescorla FJ, Scherer LR, Vaughan WG. Improved survival in children with esophageal perforation. Arch Surg. 1996;131(6):604-10; discussion 11 (PMID: 8645066)
[13] Maeder M, Ullmer E. Pneumomediastinum and bilateral pneumothorax as a complication of cocaine smoking. Respiration. 2003;70(4):407 (PMID: 14512677)
[14] Wong KS, Wu HM, Lai SH, Chiu CY. Spontaneous pneumomediastinum: analysis of 87 pediatric patients. Pediatr Emerg Care. 2013;29(9):988-91 (PMID: 23974718)
[15] Lee CY, Wu CC, Lin CY. Etiologies of spontaneous pneumomediastinum in children in middle Taiwan. Pediatr Pulmonol. 2010;45(9):869-73 (PMID: 20687204)
[16] Yamada K, Shinmoto H, Hamamoto M, Yoshida Y, Kawauchi T, Kaji T, et al. Pneumonia induced by swine-origin influenza A (H1N1) infection: chest computed tomography findings in children. Jpn J Radiol. 2011;29(10):712-7 (PMID: 22009423)
[17] Caceres M, Ali SZ, Braud R, Weiman D, Garrett HE. Spontaneous pneumomediastinum: a comparative study and review of the literature. Ann Thorac Surg. 2008;86(3):962-6 (PMID: 18721592)
[18] Bejvan SM, Godwin JD. Pneumomediastinum: old signs and new signs. AJR Am J Roentgenol. 1996;166(5):1041-8 (PMID: 8615238)
[19] Gerazounis M, Athanassiadi K, Kalantzi N, Moustardas M. Spontaneous pneumomediastinum: a rare benign entity. J Thorac Cardiovasc Surg. 2003;126(3):774-6 (PMID: 14502153)
Case information
| URL: | https://www.eurorad.org/case/15352 |
| DOI: | 10.1594/EURORAD/CASE.15352 |
| ISSN: | 1563-4086 |
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Figure 1
University Hospital Limerick, Ireland
