Pediatric spontaneous tension pneumothorax in Langerhans cell histiocytosis

Abstract

Langerhans cell histiocytosis is a rare hematologic disorder caused by the proliferation of specialized dendritic cells. Pulmonary manifestations occur in 20% to 50% of multisystem disease, but isolated pulmonary disease is rare. Spontaneous pneumothorax occurs in up to 10% of pediatric pulmonary cases. We present the case of a 3-year-old boy who presented for tachypnea and chest pain with cough, rhinorrhea, and congestion. He was discharged with a diagnosis of upper respiratory infection. The patient returned to the emergency department and was found to have a tension pneumothorax, which was emergently treated with thoracostomy. The subsequent workup revealed Langerhans cell histiocytosis with pulmonary disease and jaw involvement. Although tension pneumothorax is often associated with trauma, several medical conditions are predispositional.

Spontaneous tension pneumothorax is a rare presentation in the pediatric emergency department, but immediate diagnosis and treatment are necessary to avoid significant morbidity. This, along with other serious complications, can be the presenting sign of Langerhans cell histiocytosis (LCH). LCH must be considered on the differential diagnosis in the background of cystic bullae disease of the lungs. A survey of bone, brain, and skin is important in prognosis and treatment choice and should be incorporated in the care of suspected LCH cases. Life-threatening complications may be the presenting symptom of rare diseases, and front-line providers must maintain a high degree of suspicion with seemingly straightforward patients.

CASE PRESENTATION

A 3-year-old Hispanic boy presented to the emergency department with his mother, who stated that he woke up complaining of chest pain and was breathing quickly. He had cough, congestion, and rhinorrhea for the previous 3 days. He had been seen in the emergency department the day prior and was discharged with a diagnosis of upper respiratory infection. The patient had also been seen at the dentist a few days earlier for jaw infection and an erosion on the right maxilla. He had a respiratory rate of 48 breaths per minute and a room air oxygen saturation of 100%. He had decreased breath sounds on the right thorax and abdominal retractions. A chest x-ray revealed a pneumothorax on the right with tension physiology (Figure 1a). An 8 French chest tube was placed. Computed tomography of the chest revealed diffuse cystic-bullous disease of the lungs bilaterally (Figure 1b).

Figure 1.

Patient imaging. (a) Chest x-ray showing right-sided tension pneumothorax. (b) Computed tomography demonstrating diffuse cystic disease in the lungs.

Upon admission, the working differential diagnoses included cystic fibrosis vs LCH. Cystic fibrosis was deemed unlikely due to a normal newborn screen, the age of onset of pulmonary findings, and the severity of the pulmonary findings. An osseous survey was negative. Computed tomography of the mandible revealed periodontal osseous erosions of the mandibular molars and the base of tooth A, representing an oroantral fistula. Oral biopsies confirmed a diagnosis of LCH. The patient also had a bone marrow biopsy, extraction of nonviable teeth, and a port placed for chemotherapy. The oroantral fistula was closed with a tissue flap. Tissue and bone samples from the mandible and maxilla confirmed the diagnosis of LCH with positive S100 and CD1a immunostains.¹ Bone marrow biopsies and magnetic resonance imaging of the brain showed no indication of disease. The patient began chemotherapy with vinblastine and prednisone. A chest x-ray on hospital day 9 revealed a resolved tension pneumothorax and the chest tube was pulled. He was discharged in stable condition.

DISCUSSION

LCH is a rare hematologic disorder affecting <1 in 200,000 children <15 years of age.² It is due to the clonal proliferation of dendritic cells.³ While the exact etiology is still unknown, it appears that a large number of cases are due to mutations that activate the RAS-RAF-MEK-ERK pathway.⁴ The role of BRAF mutations in the disease process is unclear. While isolated pulmonary involvement of LCH is rare in the pediatric population, it is reported to be present in 20% to 50% of pediatric cases of multisystem disease.^5,6 Spontaneous pneumothorax occurs in only about 10% of pediatric cases with pulmonary LCH and is largely due to parenchymal lung destruction and bullae formation.⁷ Because so many pediatric cases present at the multisystem stage of the disease, a large variety of clinical manifestations may be seen and may make early diagnosis difficult (Table 1). Most commonly, pediatric patients present initially with skin manifestations or bone pain.⁸

Table 1.

Common presenting symptoms of Langerhans cell histiocytosis based on organ system

Organ system	Symptoms
Pulmonary	Shortness of breath
Cutaneous	Scaly red rash, mucous membrane lesions
Osseous	Painful granulomas
Liver	Jaundice, hepatomegaly
Lymphatic	Swollen lymph nodes

Low-risk LCH in children is estimated to have a survival rate of 99%, with high-risk LCH having a survival rate of 80% with the prominent possibility of relapse.⁹ Prognosis is associated with vital organ involvement. Some studies have found that isolated pulmonary involvement is not a negative prognostic factor unless parenchymal damage is extensively irreversible, and involvement of organs such as liver, bone, and spleen confers a worse prognosis.¹⁰ The management of LCH depends on the presentation of the lesion or organ systems involved. The treatment of multisystem LCH usually consists initially of a combination of vinblastine and prednisone. The disease is reevaluated after 6 weeks; if it is responsive to chemotherapy but active disease is still present, chemotherapy is continued.⁸

Our patient had multisystem disease involving the lung and maxilla but had no disease in the higher-risk organs and therefore had a good prognosis. One year of treatment was planned with chemotherapy, including vinblastine and prednisolone.