visual diagnosis: tension pneumothorax with evolving cysts in … · tension pneumothorax with...

Tension Pneumothorax with Evolving Cysts in an InfantAriel Stein, MD,*† Helena Molero, MD,*† Donavon Hess, MD, PhD,*‡ Mark Luquette, MD,*§ Michael B. Pitt, MD*†

*University of Minnesota School of Medicine, Minneapolis, MN†Department of Pediatrics‡Department of Surgery, and§Department of Laboratory Medicine, University of Minnesota Masonic Children’s Hospital, Minneapolis, MN

PRESENTATION

A 5-month-old previously healthy term male infant presents to a rural emergency

department (ED) for a 1-week history of increasing congestion, poor oral intake, and

a temperature of 103°F (39.4°C). He is being treated with amoxicillin for presumed

pneumonia. His examination in the ED is significant for scattered rhonchi andmild

dehydration. His chest radiograph reveals inflammatory changes without a focal

infiltrate (Fig 1). However, because this is his fourth presentation to the ED during

this illness, he is admitted for observation. During the next 2 days his respiratory

distress and tachypnea progressively worsen. On day 3 of his hospitalization he begins

having episodes of desaturation and worsening retractions refractory to oxygen via

low-flow nasal cannula. His examination at this time is significant for diffuse rhonchi

throughout both lung fields with decreased air entry at the lung bases. Because his

clinical status is deteriorating, he is transferred to a higher level of care.

On arrival at the referral center he is lethargic, with decreased breath sounds and

persistent desaturations. A respiratory swab polymerase chain reaction is positive for

respiratory syncytial virus (RSV). His chest radiograph reveals a large right-sided

tension pneumothorax (Fig 2). A pigtail chest tube is emergently placed, and his work

of breathing improves. Within 2 days he is no longer requiring supplemental oxygen.

The medical team is unable to successfully put the chest tube to water seal, however,

because each time it is sealed there is a rapid re-accumulation of his pneumothorax.

After several unsuccessful attempts, his chest tube is placed back to suction and he is

airlifted, via helicopter, to a pediatric tertiary care center for further evaluation, now 11

days after his initial presentation. His chest radiograph just before transfer reveals a

well-positioned chest tube with interval decrease in the size of the pneumothorax.

On arrival at the tertiary care center he is well appearing, with no increased work of

breathing, and is saturating 97% to 100% on room air. His lung sounds are clear

bilaterally, but an air leak is auscultated on inspiration. He has no crackles, wheezes, or

rhonchi. Chest radiography is repeated to verify the position of the chest tube and

incidentally reveals a large cystic-appearing lesion in his right lung that has not been

previously described (Fig 3). Computed tomography of the chest is performed that

reveals multiple air-filled cystic lesions in the right upper lobe of the lung as well as a

persistent right-sided pneumothorax (Fig 4). Surgery and pulmonology are consulted

for co-management. On day 17 of his cumulative hospitalization he undergoes wedge

resection of the right upper lobe of his lung without complications. Samples of the

cystic lesions are sent to the pathology laboratory to confirm the diagnosis.

AUTHOR DISCLOSURE Drs Stein, Molero,Hess, Luquette, and Pitt have disclosed nofinancial relationships relevant to thisarticle. This commentary does not contain adiscussion of an unapproved/investigativeuse of a commercial product/device.

ABBREVIATIONS

CPAM congenital pulmonary airway

malformation

ED emergency department

RSV respiratory syncytial virus

e42 Pediatrics in Review

VISUAL DIAGNOSIS

by guest on July 7, 2021http://pedsinreview.aappublications.org/Downloaded from

http://pedsinreview.aappublications.org/

DIAGNOSIS

The diagnosis of air leak secondary to rupture of a functional

alveolar bleb, likely due to proximal mucus plugging in the

course of RSVbronchiolitis, was confirmedby pathology (Fig 4).

DISCUSSION

Spontaneous pneumothorax in children outside of the

newborn period is exceedingly rare, with an estimated

prevalence of only 1 in every 10,000 hospitalized children.

The bulk of reported cases are secondary pneumothoraces

due to an acute infection, trauma, or congenital malformation.

(1) In our case, we initially considered a congenital malfor-

mation such as congenital pulmonary adenomatoid mal-

formation (CPAM), given the well-defined cystic lesions on

imaging. CPAMs are the most common form of congenital

parenchymal lung malformations, with an estimated inci-

dence of 1 in 11,000 to 1 in 35,000 live births. (2) Most

CPAMs are diagnosed prenatally during routine 20-week

ultrasonography, and complications may include hydrops

fetalis, recurrent infections in childhood, or malignant

transformation. We reviewed prenatal ultrasonography of

this patient, and there were no signs of lung lesions, and

neither were these lesions visible on previous radiographs. In

addition, spontaneous pneumothorax is a rarely described

comorbidity of CPAM. This was definitively ruled out with

histologic examination of the surgical specimen.

Also on the differential diagnosis was postinfectious

pneumatocele. A pneumatocele is a thin-walled air-filled cyst

in the lung parenchyma, sometimes seen in children sec-

ondary to a severe pulmonary infection, most commonly

Staphylococcus aureus pneumonia. It develops when the

necrotic airway forms a cystic lesion connected to the

bronchial tree. Similar to the ball valve physiology described

later herein, air gets trapped in this lesion, causing hyper-

inflation of the cyst and resulting pneumothorax. (3) His-

tologically, samples obtained from these patients reveal

necrotic debris and multinucleated giant cells. (4) Children

with this condition are generally quite ill with hypoxic re-

spiratory failure requiring aggressive management in an

ICU setting. (5) Because this patient had a relatively short and

mild preceding illness, pneumatocele was less likely, and it

was ruled out by histologic analysis.

This case is remarkable for the abrupt change in the

appearance of the radiograph before and after transfer to the

tertiary care center. We considered the possibility that air

transport contributed to the change. As explained by Boyle’s

law, lower barometric pressure at high altitude causes

Figure 1. Anteroposterior and lateralchest radiographs on hospital day 1show patchy, predominantly perihilarairspace opacities, consistent withviral inflammatory/reactive airwaydisease. No lobar consolidation. Nopneumothorax.

Figure 2. Anteroposterior chest radiograph on hospital day 4 shows alarge right-sided tension pneumothorax with tension physiology.

Vol. 41 No. 11 NO V EM B E R 2 0 2 0 e43 by guest on July 7, 2021http://pedsinreview.aappublications.org/Downloaded from


volume expansion, which could unmask a more significant

lesion than had been previously identified. (6)(7) Although

helicopters travel at a lower altitude than fixed-wing transport

(10,000 ft vs 20,000–30,000 ft), there are predictable

changes in oxygen requirements and lung volumes at this

altitude that could worsen an air leak. (7) However, histologic

analysis revealed a thick wall surrounding the lesion, sug-

gesting an inflammatory reaction rather than a simple air

leak. In addition, the chest tube, set to suction, was func-

tioning properly and should have prevented expansion of an

intrapulmonary lesion. (7)

RSV infection was most likely the inciting event that led to

his intraparenchymal cysts and persistent air leak. Bron-

chiolitis is the most common lower respiratory tract infection

in children younger than 2 years. The incidence is estimated to

be 11.4 to 19.6 cases per 100 children before age 1 year. (8) RSV

is the most common cause. (9) Although case reports suggest

that spontaneous pneumothorax secondary to viral lower re-

spiratory tract infection occurs with an estimated prevalence of

0.6%, none were treated with surgical intervention. All re-

ported cases resolved with either needle thoracentesis or chest

tube placement. (1)(8)(9)(10)(11)

Histologic examination of the resected lung specimen

identified an air-filled cavity bordered by reparative tissue

(foamy macrophages) and foreign body giant cells (Fig 5).

There was no epithelial lining in the cavity, adjacent smooth

muscle wall, or satellite cysts, which definitively ruled out

CPAM. Although these findings were nonspecific, the results

point to a reaction that can be seen when the airway responds

to a foreign body. Similar to a foreign body in the airway,

mucus plugs can cause lung injury by a ball valve effect.

Figure 4. Contrast computed tomography of the chest on hospital day12 shows multiple air-filled cysts in the right upper lung with right-sidedpneumothorax.Figure 3. Anteroposterior chest radiograph on hospital day 11 shows a

right-sided moderate pneumothorax with a pigtail chest tube in place.Circular lucencies concerning for cystic/cavitary lesions are seen in theright lung.

Figure 5. 1, A cavity (white space on left) lined by foamy macrophages(magnified in inset). 2, Immunostain for KP-1, a macrophage marker(brown areas positive), shows a thick band of positive cells, correspondingto the foamy macrophages, lining the cavity. 3, Immunostain forcytokeratin, a marker of epithelium, shows an inverse pattern to panel 2,with the band of macrophages staining negatively in contrast to thepulmonary parenchyma on the right. 4, Immunostain for smooth muscleactin shows that there is no muscular wall adjacent to the cavity. 5, Cavity(white space on the right) lined by foreign body giant cells.

e44 Pediatrics in Review by guest on July 7, 2021http://pedsinreview.aappublications.org/Downloaded from


During inspiration, the airway expands, allowing air to pass

the obstruction. However, during expiration, the airway

collapses around the obstruction and prevents gas from

escaping. As the cycle repeats, the lung beyond the mucus

plug expands and may lead to pneumothorax. (4)

Patient Course

Our patient had no postoperative oxygen requirement after

he underwent thoracotomy with wedge resection of his right

upper lobe. The chest tube was removed on postoperative day

5, and he was discharged home. He was seen in the clinic the

following week and was well appearing, with clear breath

sounds and no increased work of breathing. He has had no

subsequent recurrences of his symptoms.

Summary• Secondary air leaks and cavity formation as sequelae of

respiratory syncytial virus (RSV) are exceedingly rare.

• Cavitary changes in the lung may develop secondary to

RSV with mucus plugs and air trapping.

• RSV is a frequent cause of pneumonitis in infants that

rarely requires surgical intervention, but it is

important to recognize the possibility of such

complications, which may occur even as the primary

infection is resolving.

References1. Alter SJ. Spontaneous pneumothorax in infants: a 10-year review.Pediatr Emerg Care. 1997;13(6):401–403

2. Stocker LJ, Wellesley DG, Stanton MP, Parasuraman R, Howe DT.The increasing incidence of foetal echogenic congenital lungmalformations: an observational study. Prenat Diagn. 2015;35(2):148–153

3. Joseph L, Shahroor S, Fisher D, Goldberg S, Picard E. Conservativetreatment of a large post-infectious pneumatocele. Pediatr Int. 2010;52(5):841–843

4. Quigley MJ, Fraser RS. Pulmonary pneumatocele: pathology andpathogenesis. AJR Am J Roentgenol. 1988;150(6):1275–1277

5. Bass HE, Diamond N, Schuman M. Triad of pneumonia,pneumatocele, and spontaneous pneumothorax in infants. J AmMedAssoc. 1954;154(2):143–144

6. Hu X, Cowl CT, BaqirM, Ryu JH. Air travel and pneumothorax.Chest.2014;145(4):688–694

7. Knotts D, Arthur AO, Holder P, Herrington T, Thomas SH.Pneumothorax volume expansion in helicopter emergency medicalservices transport. Air Med J. 2013;32(3):138–143

8. Kambouri K, Gardikis S, Tsalkidis A, Cassimos D, Deftereos S,Chatzimichael A. Late onset of spontaneous pneumothoraxcomplicating acute bronchiolitis in a 5-month-old infant: casereport and literature review. Pediatr Emerg Care. 2007;23(12):889–891

9. Silva C, Almeida AF, Ferraz C, Nunes T, Guedes Vaz L. Spontaneouspneumothorax with subcutaneous emphysema: a rare complicationof respiratory syncytial virus infection. J Clin Med Res. 2016;8(3):260–262

10. Nimkin K, Kleinman PK, Zwerdling RG, Spevak MR, O’Sullivan BP.Localized pneumothorax with lobar collapse and diffuse obstructiveairway disease. Pediatr Radiol. 1995;25(6):449–451

11. Willson DF, Landrigan CP, Horn SD, Smout RJ. Complications ininfants hospitalized for bronchiolitis or respiratory syncytial viruspneumonia. J Pediatr. 2003;143(5)(suppl):S142–S149

Vol. 41 No. 11 NO V EM B E R 2 0 2 0 e45 by guest on July 7, 2021http://pedsinreview.aappublications.org/Downloaded from


DOI: 10.1542/pir.2018-00622020;41;e42Pediatrics in Review

Ariel Stein, Helena Molero, Donavon Hess, Mark Luquette and Michael B. PittVisual Diagnosis: Tension Pneumothorax with Evolving Cysts in an Infant

ServicesUpdated Information &

http://pedsinreview.aappublications.org/content/41/11/e42including high resolution figures, can be found at:

References

st-1http://pedsinreview.aappublications.org/content/41/11/e42.full#ref-liThis article cites 11 articles, 0 of which you can access for free at:

Subspecialty Collections

bhttp://classic.pedsinreview.aappublications.org/cgi/collection/rsv_suRSVncy_medicine_subhttp://classic.pedsinreview.aappublications.org/cgi/collection/emergeEmergency Medicinefollowing collection(s): This article, along with others on similar topics, appears in the

Permissions & Licensing

https://shop.aap.org/licensing-permissions/in its entirety can be found online at: Information about reproducing this article in parts (figures, tables) or

Reprintshttp://classic.pedsinreview.aappublications.org/content/reprintsInformation about ordering reprints can be found online:


http://http://pedsinreview.aappublications.org/content/41/11/e42http://pedsinreview.aappublications.org/content/41/11/e42.full#ref-list-1http://pedsinreview.aappublications.org/content/41/11/e42.full#ref-list-1http://classic.pedsinreview.aappublications.org/cgi/collection/emergency_medicine_subhttp://classic.pedsinreview.aappublications.org/cgi/collection/emergency_medicine_subhttp://classic.pedsinreview.aappublications.org/cgi/collection/rsv_subhttp://classic.pedsinreview.aappublications.org/cgi/collection/rsv_subhttps://shop.aap.org/licensing-permissions/http://classic.pedsinreview.aappublications.org/content/reprintshttp://pedsinreview.aappublications.org/

DOI: 10.1542/pir.2018-00622020;41;e42Pediatrics in Review

Ariel Stein, Helena Molero, Donavon Hess, Mark Luquette and Michael B. PittVisual Diagnosis: Tension Pneumothorax with Evolving Cysts in an Infant

http://pedsinreview.aappublications.org/content/41/11/e42located on the World Wide Web at:

The online version of this article, along with updated information and services, is

Print ISSN: 0191-9601. Illinois, 60143. Copyright © 2020 by the American Academy of Pediatrics. All rights reserved. published, and trademarked by the American Academy of Pediatrics, 345 Park Avenue, Itasca,publication, it has been published continuously since 1979. Pediatrics in Review is owned, Pediatrics in Review is the official journal of the American Academy of Pediatrics. A monthly


http://pedsinreview.aappublications.org/content/41/11/e42http://pedsinreview.aappublications.org/

Tension Pneumothorax with Evolving Cysts in an InfantPresentationDiagnosisDiscussionPatient Course

Summary

visual diagnosis: tension pneumothorax with evolving cysts in … · tension pneumothorax with...

Documents