Authors Slostad, JA1, Higgins, AS1, Dempsey TM2, Dunn WF2 1Department of Internal Medicine, 2Department of Pulmonary and Critical Care Medicine Mayo Clinic, Rochester, Minnesota, USA
Case
A 65-year-old non-smoking female presented to the emergency
department with one week of dyspnea, pleuritic chest pain, and dry
cough.
On exam, she was afebrile, hemodynamically stable with blood pressure
150/77, oxygen saturation of 92% on room air, and respiratory rate of
22. She had shallow work of breathing with right-sided absent breath
sounds in the mid and lower lung base. She had several white
dome-shaped papules scattered over her forehead and face. Cardiac,
neurologic, and abdominal exams were unremarkable. Family history was
significant for a brother with tension pneumothorax requiring
pleurectomy. Chest x-ray was obtained (Figure 1).
Figure 1: Chest x-ray obtained in Emergency Department:
Question
What is the most likely cause of her acute onset of shortness of breath, pleuritic chest pain, and dry cough?
A. Malignant pleural effusion B. Primary pneumothorax C. Secondary pneumothorax with tension physiology D. COPD exacerbation E. Community acquired pneumonia
Answer
Answers: C. Secondary pneumothorax with tension physiology
Discussion
The patient’s clinical presentation of chest pain, dyspnea, dry
cough, and physical exam demonstrating absence of breath sounds, along
with confirmatory imaging, is all most consistent with spontaneous
pneumothorax. Other common physical exam signs seen in pneumothorax
include decreased breath sounds, tactile fremitus and hyper-resonance to
percussion. Her chest x-ray showed loss of right-sided lung markings
with a deep sulcus sign (black arrow, Figure 1B), which is a deep
costophrenic angle ipsilateral to the side of the pneumothorax.
Secondary pneumothorax, rather than primary, is more consistent with the
patient’s family history of pneumothorax and skin findings of
fibrofolliculomas, which are a type of skin hamartoma (Figure 3). Our
patient has Birt-Hogg-Dubé syndrome (BHDS), which is a hereditary
syndrome with pulmonary cysts, secondary spontaneous pneumothorax, and
skin hamartomas. BHDS is a classic, but rare, cause of secondary
pneumothorax1.
A computed tomography (CT) of the chest was performed prior to her
presentation to the emergency department, which showed bilateral cystic
lung lesions (Figure 2A). On presentation to the emergency department,
the initial chest x-ray showed a large right sided tension pneumothorax
(2B, arrows). She underwent emergent chest tube placement with
improvement of her symptoms. She proceeded to right sided
video-assisted thoracoscopic surgery (VATS) with partial pleurectomy and
mechanical pleurodesis (Figure 2C) given her risk of recurrence of
secondary spontaneous pneumothorax in the setting of BHDS. Following
the procedure, she had resolution of the right-sided pneumothorax, but
developed new subcutaneous air (arrow), which was managed
conservatively. Chest x-ray 1 month later showed complete resolution of
the pneumothorax, mediastinal emphysema, and subcutaneous emphysema
(2D). Long-term follow-up did not demonstrate recurrence of secondary
spontaneous pneumothorax.
Figure 2: (A-D)
Figure 3: Fibrofolliculoma
Pneumothorax is a clinical diagnosis, and imaging is used to confirm the
diagnosis. The patient’s clinical presentation makes malignant pleural effusion,
COPD exacerbation, and community acquired pneumonia less likely. An upright
posteroanterior chest radiograph can help confirm the diagnosis if absence of
lung markings, deep sulcus sign, and mediastinal shift are
demonstrated3. Given the contralateral mediastinal shift on our
patient’ chest radiograph (Figure 2B), there is evidence of tension physiology
without hemodynamic compromise. However, tension physiology on chest x-ray can
portend hemodynamic decline, and therefore, clinicians should have high clinical
suspicion for pneumothorax as waiting on results of chest x-ray may result in
clinical decompensation. Spontaneous pneumothorax is classified as primary or
secondary depending on the presence or absence of underlying lung disease.
Primary pneumothorax occurs without underlying lung disease or precipitating
event, whereas secondary pneumothorax can occur in a variety of lung
pathology1,3. The differential diagnosis for secondary spontaneous
pneumothorax includes underlying lung disease (COPD with emphysema, cystic
fibrosis, severe asthma, BHDS), infections (bacterial pneumonia,
Pneumocystis jirovecii
pneumonia, tuberculosis), interstitial lung disease (sarcoidosis, idiopathic
pulmonary fibrosis, lymphangioleiomyomatosis, histiocytosis X), connective
tissue and autoimmune disease, and lung malignancy3. Secondary causes
of pneumothorax tend to be more severe and life-threatening given the underlying
lung disease, and require more prompt evaluation and treatment3.
BHDS is an autosomal dominant syndrome with 600 families described world-wide, although it is likely underdiagnosed1.
The mutation is in a tumor suppressive gene encoding for the folliculin
protein, and our patient had a known folliculin (FLN-C) gene mutation1,4. The syndrome involves the lungs, skin, and kidneys, with lung cysts as the hallmark feature present in 67-90% of patients1. Cysts tend to appear in lower lung bases with thin-walls and irregular, variable shapes1.
Patients have skin hamartomas, and most commonly fibrofolliculomas,
which are white dome shaped papules usually located on face and neck5. Patients also have increased risk of renal tumors, and should undergo routine surveillance1. Penetrance of clinical manifestations of disease varies within families6. BHDS may first present with a spontaneous pneumothorax unless a family history of disease is known5. There is a 50-fold increased risk of pneumothorax with 40-75% of patients experiencing at least one spontaneous pneumothorax1. Due to this risk, early pleurodesis is recommended6.
Clinicians should routinely consider secondary causes for patients
presenting with pneumothorax, as this changes management of pneumothorax
treatment. Awareness of inherited causes of secondary pneumothorax in
patients is critical to appropriate diagnosis and management of patients
with secondary pneumothorax.
References
Jensen DK, Villumsen A, Skytte AB, Madsen, MG, Sommerlund M,
Bendstrup E. Birt–Hogg–Dubé syndrome: a case report and a review of the
literature. European Clinic Respiratory Journal. 2017; 4: 1, 1292378.
Noppen M, De Keukeleire T. Pneumothorax. Respiration. 2008;76(2):121-7.
Skolnik K, Willis TH, Dornan K, Perrier R, Burrowes PW, Davidson WJ.
Birt-Hogg-Dubé syndrome: a large single family cohort. Respiratory
Research. 2016; 17:22.
Bock K, Lohse Z, Madsen PH, Hilberg O. Birt-Hogg-Dubé syndrome:
spontaneous pneumothorax as a first symptom. BMJ Case Rep. 2018 Jan
9;2018. pii: bcr-2017-219979. doi: 10.1136/bcr-2017-219979.
Gupta N, Seyama K, McCormack FX, et al. Pulmonary manifestations of Birt-Hogg-Dubé syndrome. Fam Cancer 2013; 12:387–96.