Langerhans Cell Histiocytosis (Eosinophilic Granuloma)

Key Facts
  • Diffuse destructive disorder of distal airways caused by granulomas containing Langerhans cells
  • Smoking-related lung disease
  • May present with pneumothorax (17%) or develop recurrent pneumothoraces
  • Upper and mid lung reticulonodular opacities, sparing costophrenic angles
  • HRCT: irregular small nodules and bizarre shaped cysts
  • Variable prognosis
Imaging Findings

Chest radiography

  • Upper and mid lung reticulonodular opacities, sparing costophrenic angles
  • Multiple ill-defined nodules, measuring 1-15 mm
  • Cysts, honeycombing, blebs, bullae
  • Increase in lung volume
  • May see rib involvement: lytic expansile lesion with beveled edges
  • No pleural effusion
  • 2/3rds of patients eventually have resolution or stable disease

CT/HRCT

  • HRCT findings may be characteristic
  • Upper and mid lung predominance, sparing costophrenic angles
  • Irregular centrilobular nodules (usually 1- 10 mm), some cavitate
  • Cysts (1–20 mm) with thin or thick walls, some lobulated, septated, or bizarre shaptes
  • Ground glass opacities, interstitial lines, septal lines
  • Burned out disease may resemble emphysema
Differential Diagnosis
  • Lympangioleiomyomatosis (LAM)
  • Differentiation
    • LAM has no nodules
    • Round cysts are uniformly distributed
    • Involves costophrenic angles
    • Chylothorax
Pathological Features
  • Smoking-related lung disease (95% smoke)
  • Diffuse destructive disorder of distal airways caused by granulomas containing Langerhans cells
  • Langerhan cell processes antigen, contains Bierbeck granule
  • 1 – 15 mm nodules (granulomas) in walls of small airways
  • Nodule cavities are due to distended airways
  • Adjacent lung may show desquamative interstitial pneumonitis (DIP) and BOOP and respiratory bronchiolitis
  • Eventually, fibrosis, honeycombing, cysts and emphysema
  • In adult, LCH most commonly seen only in lung
  • Hand-Schuller-Christian Disease – involves lung, bone and pituitary – diabetes insipidus (adults and adolescents)
  • Letterer-Siwe – multiorgan involvement (infants), poor prognosis
Clinical Presentation
  • Uncommon
  • White adults, mostly at ages 20 – 30, heavy smokers, males = females
  • Cough, dyspnea, chest pain, fever, weight loss, or asymptomatic (17%)
  • May present with pneumothorax (17%) or develop recurrent pneumothoraces
  • Associated with lymphoma, leukemia and solid tumors
  • Diagnosis: transbronchial lung biopsy, BAL with > 5% CD1A positive Langerhans cells, and or HRCT. Open lung biopsy if all else fails
  • Treatment
    • smoking cessation, steroids if disease is progressing
    • May recur in transplanted lung
    • Variable prognosis from complete remission to respiratory failure
    • Mortality is < 5%, worse in men, old age and in patients with recurrent pneumothoraces
References

Brauner MW, Grenier P, Tijani K, et al. Pulmonary Langerhans cell histiocytosis: evolution of lesions on CT scans Radiology 204:497-502, 1997
Friedman PJ, Liebow AA , Sokoloff J. Eosinophilic granuloma of lung. Clinical aspects of primary histiocytosis in the adult Medicine (Baltimore) 60:385-396, 1981
Moore AD, Godwin JD, Muller NL, et al. Pulmonary histiocytosis X: comparison of radiographic and CT findings Radiology 172:249-254, 1989