March 2023 Medical Image of the Month: Spontaneous Pneumomediastinum as a Complication of Marijuana Smoking Due to Müller's Maneuvers

Figure 1. PA chest radiograph obtained at the time of admission (A) demonstrating gas densities (arrows) along left heart border, left paratracheal stripe, upper mediastinum and neck extending into the right supraclavicular fossa in keeping with pneumomediastinum. Follow-up PA chest radiograph performed just before discharge (B) demonstrates resolution of pneumomediastinum.

Figure 2. Two axial images through the anterior mediastinum obtained from a contrast-enhanced chest CT demonstrating gas densities (arrows) in the mediastinum anterior to the heart and around the esophagus in-keeping with pneumomediastinum.

A 35-year-old woman with a medical history notable for celiac disease, ulcerative colitis, and bipolar disorder presents to the Emergency Department for evaluation of a strange sensation in the chest and neck associated with nausea and vomiting for one day. The patient also reports persistent nausea and markedly decreased oral intake for the last four days. She reported no concomitant symptoms such as shortness of breath, wheezing, fever, or chills. She denies diarrhea or constipation. Socially, she admits to smoking marijuana daily, and alcohol occasionally.

Vital sign shows blood pressure 147/97 mmHg, pulse 92 BPM, temperature 37.3°C, SpO2 96% breathing ambient air. She appears nontoxic and well-nourished, and the lungs are clear to auscultation bilaterally without any wheezes, rales, or rhonchi. The heart examination reveals a regular rate and rhythm, with normal S1 and S2 heart sounds and no murmurs, rubs, or gallops. The abdomen is soft, non-tender, and not distended. Her extremities do not exhibit any clubbing, cyanosis, or edema. CBC and CMP were unremarkable, and the drug screen test was positive for THC. An ECG is obtained (not shown here), which reveals a normal sinus rhythm with a heart rate of 55 beats/min and no ST-segment or T-wave abnormalities. Chest x-ray and CTA chest, CT abdominal with oral contrast were obtained (Figures 1 and 2). Upon further questioning of the patient’s social history, it was discovered that she smokes marijuana daily using water pipes, and while utilizing a water pipe she attempted a full inspiration against a closed mouth and nose, a technique known as the Müller’s maneuver.

Spontaneous pneumomediastinum (SPM) is a rare condition in which air escapes from the lungs and collects in the mediastinum, the space between the lungs. SPM is almost always a benign, self-limited condition. While SPM can be caused by a variety of factors, including coughing, vomiting, and physical trauma, this case report presents a rare instance of SPM caused by marijuana smoking. Spontaneous pneumomediastinum (SPM) was reported in 1939 by Johns Hopkins clinician Louis Hamman for whom the Hamman sign is named. It is defined as free air or gas contained within the mediastinum, which almost originates from the alveolar space or the conducting airways. Many authors distinguish spontaneous pneumomediastinum as a form of pneumomediastinum that is not associated with blunt force or penetrating chest trauma, endobronchial or esophageal procedures, neonatal lung disease, mechanical ventilation, chest surgery, or other invasive procedures.

The mechanism by which marijuana smoking leads to pneumomediastinum is not well understood, but it is thought to involve increased intra-alveolar pressure and alveolar rupture. This can result in the escape of air into the mediastinum, leading to the development of pneumomediastinum. SPM has been associated with the inhalation of drugs such as cocaine, amphetamines, and marijuana (1-4). Attempted inspiration through a closed glottis or Muller’s maneuver results in a drop in intrathoracic pressure, which increases alveolar air volume, causing alveolar distension and rupture which can cause shear damage and air leakage along a bronchovascular bundle into the mediastinum.

The patient, in this case, was a 35-year-old woman with a history of marijuana smoking who presented with symptoms of chest pain, shortness of breath, and dysphagia. Physical examination revealed subcutaneous emphysema and a chest x-ray confirmed the presence of SPM. This case highlights the potential respiratory complications associated with marijuana smoking, which can lead to SPM and other adverse outcomes. While marijuana use is becoming increasingly common and accepted, it is important for healthcare providers to be aware of the potential risks and to educate their patients about the potential consequences of marijuana use. Further research is needed to understand the full extent of the respiratory effects of marijuana smoking and to develop appropriate interventions and treatments.

Mohammad Abdelaziz Mahmoud DO

Doctors Medical Center of Modesto and Emanuel Medical Center

Modesto and Turlock, CA USA

References

1. Weiss ZF, Gore S, Foderaro A. Pneumomediastinum in marijuana users: a retrospective review of 14 cases. BMJ Open Respir Res. 2019 Feb 12;6(1):e000391. [CrossRef] [PubMed]
2. Al-Mufarrej F, Badar J, Gharagozloo F, Tempesta B, Strother E, Margolis M. Spontaneous pneumomediastinum: diagnostic and therapeutic interventions. J Cardiothorac Surg. 2008 Nov 3;3:59. [CrossRef] [PubMed]
3. Puri C, Rhee K, Harish VK, Slack D. Marijuana induced spontaneous pneumomediastinum. J Community Hosp Intern Med Perspect. 2021 Jun 21;11(4):516-517. [CrossRef] [PubMed]
4. Motes A, Laoveeravat P, Thongtan T, Nugent K, Islam S, Islam E. Marijuana use-induced spontaneous pneumomediastinum. Proc (Bayl Univ Med Cent). 2020 Dec 7;34(2):274-275. [CrossRef] [PubMed]

Cite as: Mahmoud MA. March 2023 Medical Image of the Month: Spontaneous Pneumomediastinum as a Complication of Marijuana Smoking Due to Müller's Maneuvers. Southwest J Pulm Crit Care Sleep. 2023;26(3):31-33. doi: https://doi.org/10.13175/swjpccs058-22 PDF 

February 2023 Medical Image of the Month: Reversed Halo Sign in the Setting of a Neutropenic Patient with Angioinvasive Pulmonary Zygomycosis

Figure 1. Axial reconstructions from unenhanced (A) and enhanced (B) chest CTs performed 1 week prior to admission (A) and at admission (B) demonstrating rapid interval increase in size of an initially small left upper lobe nodule (arrow) with extensive central necrosis manifesting as a “reversed halo” sign (circled, B).

Figure 2. Sagittal reconstructions from unenhanced (A, C) and enhanced (B) chest CTs through the left lung performed 1 week prior to admission (A), at admission (B), and 2 weeks after admission (C). Small nodules on initial CT (arrows, A) rapidly grow with prominent central necrosis (circle, B). The follow up CT after the patient started improving demonstrates an “air crescent” sign (arrowhead, C) consistent with improving angioinvasive fungal infection.

Figure 3. Low power view, GMS special stain (A) demonstrating a pulmonary artery with fungal elements invading into the wall and out into the surrounding lung parenchyma. There are variable and broad hyphae, with rare septation, many short fragments compatible with Rhizopus species grown in fungal culture. Low power view, H & E stain (B) from a different portion of the sample demonstrating fungal hyphae and spores with thinner morphology, right angle-branching, and calcium oxalate crystals, morphologically compatible with Aspergillus. This may represent secondary colonization of damaged lung.

A 66-year-old man presented to our emergency department with fever and lethargy. A CBC demonstrated profound neutropenia with an absolute neutrophil count of <0.50x10⁹ cells/L (critically low). The patient was admitted and workup for febrile neutropenia was begun. The patient’s past medical history includes CLL (recently confirmed to be in remission by bone marrow biopsy), hypogammaglobulinemia/capillary leak syndrome (presumably related to obinutuzumab therapy, for which patient receives monthly IVIG), and coccidioidomycosis (for which the patient has been followed by infectious disease at our institution, is on fluconazole). An outpatient chest CT performed 1 week prior to presentation to follow up pulmonary nodules demonstrated a few scattered small, but new, inflammatory-appearing nodules (Figure 1A, 2A).

A repeat chest CT was performed at time of admission, 7 days after the initial CT, which demonstrated marked interval increase in size of the small nodules, now represented as large areas of mass-like consolidation including a large finding in the left upper lobe displaying a reversed-halo sign (Figure 1B, 2B). Rapidly progressive fungal infection in the setting of neutropenia was favored. Due to rapid clinical deterioration and development of sites of infection outside the lungs, the decision was made to resect the left upper lobe for source control. The patient tolerated the procedure well, pathology from the specimen demonstrated pulmonary angioinvasive zygomycosis (mucormycosis) with broad areas of hemorrhagic pulmonary infarction, neutrophilic infiltrates and organizing hemorrhagic pneumonia. There were many invasive fungal organisms extending through the infarcted lung tissue. A culture of the lung showed Rhizopus species. There was prominent fungal angioinvasion with thrombosis in and around the infarcted lung. There were additional fungi in a bronchus that were thinner with more spores, septations, and elaborating oxalate crystals that were more consistent with Aspergillus species suggesting polymicrobial fungal infection. The patient was started on amphotericin B and posaconazole as well as filmgastrin. His neutropenia slowly improved, as did his clinical situation. A follow-up CT performed  2 weeks later demonstrated an air-crescent sign in the left lower lobe consistent with improving angioinvasive fungal infection in the setting of resolving neutropenia (Figure 2C). 

The reversed halo sign consists of a finding of peripheral consolidation and central ground glass, in counter distinction to the CT halo sign, which consists of a nodule or mass (or mass-like consolidation) surrounded by ground glass (1). Interestingly, the halo sign was initially described in the setting of angioinvasive aspergillus infection (2), yet the opposite “reversed halo” sign is, in this case and many other cases, also described in the setting of invasive pulmonary fungal infection (3). The reversed halo sign was classically described in the setting of cryptogenic organizing pneumonia (4), where there is central disease clearing. This sign is also described as the “atoll” sign (5), representing relatively normal, improving lung in that situation. In the setting of invasive fungal infection, the central ground glass represents the opposite situation: dead, necrotic lung rather than improving lung. Although organizing pneumonia and invasive fungal infection are well-recognized causes of the reversed halo sign, the sign is by no means specific. Reversed halo signs can be seen in a wide variety of pathologies including paracoccidioidomycosis, pneumocystis pneumonia, tuberculosis, community-acquired pneumonia, lymphomatoid granulomatosis, granulomatosis with polyangiitis, lipoid pneumonia, sarcoidosis, pulmonary infarction, post-radiofrequency ablation and more (6).

Clinton Jokerst MD¹, Yasmeen Butt MD², Ann McCullough MD², Carlos Rojas MD¹, Prasad Panse MD¹, Kris Cummings MD¹, Eric Jensen MD¹ and Michael Gotway MD¹

Departments of Radiology¹

Mayo Clinic Arizona, Scottsdale, AZ USA

Departments of Pathology²

Mayo Clinic Arizona, Scottsdale, AZ USA

References

1. Hansell DM, Bankier AA, MacMahon H, McLoud TC, Müller NL, Remy J. Fleischner Society: glossary of terms for thoracic imaging. Radiology. 2008 Mar;246(3):697-722. [CrossRef] [PubMed]
2. Kuhlman JE, Fishman EK, Siegelman SS. Invasive pulmonary aspergillosis in acute leukemia: characteristic findings on CT, the CT halo sign, and the role of CT in early diagnosis. Radiology. 1985 Dec;157(3):611-4. [CrossRef] [PubMed]
3. Wahba H, Truong MT, Lei X, Kontoyiannis DP, Marom EM. Reversed halo sign in invasive pulmonary fungal infections. Clin Infect Dis. 2008 Jun 1;46(11):1733-7. [CrossRef] [PubMed]
4. Kim SJ, Lee KS, Ryu YH, Yoon YC, Choe KO, Kim TS, Sung KJ. Reversed halo sign on high-resolution CT of cryptogenic organizing pneumonia: diagnostic implications. AJR Am J Roentgenol. 2003 May;180(5):1251-4. [CrossRef] [PubMed]
5. Zompatori M, Poletti V, Battista G, Diegoli M. Bronchiolitis obliterans with organizing pneumonia (BOOP), presenting as a ring-shaped opacity at HRCT (the atoll sign). A case report. Radiol Med. 1999 Apr;97(4):308-10. [PubMed]
6. Godoy MC, Viswanathan C, Marchiori E, Truong MT, Benveniste MF, Rossi S, Marom EM. The reversed halo sign: update and differential diagnosis. Br J Radiol. 2012 Sep;85(1017):1226-35. [CrossRef] [PubMed]

Cite as: Jokerst C, Butt Y, McCullough A, Rojas C, Panse P, Cummings K, Jensen E, Gotway M. February 2023 Medical Image of the Month: Reversed Halo Sign in the Setting of a Neutropenic Patient with Angioinvasive Pulmonary Zygomycosis. Southwest J Pulm Crit Care Sleep. 2023;26(2):21-23. doi: https://doi.org/10.13175/swjpccs003-23 PDF