INTRODUCTION:Long-term radiation effects on the endobronchial tree following therapy for lung malignancies are not well described. We report a case and literature review.
CASE PRESENTATION:A 69 year old female with a history of T2N0M0 squamous cell lung cancer underwent right upper lobectomy in 1993. She recurred in 1994 with an enlarging right hilar mass and was treated with radiation therapy alone. Since that time, the patient was asymptomatic until presenting with a chronic cough and occasional scant hemoptysis. She also noted chronic left sided chest pain that worsened over the previous year. Physical exam was notable for thoracic asymmetry of the left upper chest wall with mild erythema. Lungs were clear. PET scan and bone scan did not suggest any disease recurrence. CT scan showed multiple endobronchial lesions. Fiberoptic bronchoscopy demonstrated multiple non-obstructing polypoid, friable nodules involving the distal trachea, carina and proximal mainstem bronchi. The distal airways appeared normal. Biopsies from multiple lesions were obtained and forceps removal of larger lesions was performed. The histopathology demonstrated atypical squamous cells with focal nuclear atypia and parakeratosis, but there were no malignant changes. Notably, areas of endobronchial atypia occurred only in the regions of her previous radiation port.
DISCUSSIONS:Post radiation effects on the lung are usually described as acute pneumonitis or chronic parenchymal fibrosis. Endobronchial changes are infrequently described with reports of focal necrosis and increased mucous production. However, the endobronchium is generally thought to be radioresistant. Radiation-induced squamous metaplasia of other organs has been described, including the cervix, urinary bladder and prostate. We hypothesize that the lesions of the endobronchial tree seen in this case are changes consistent with radiation-induced squamous metaplasia, an iatrogenic consequence of her radiation therapy. Optimal management and evaluation for follow up in patients with radiationinduced neoplasia is unknown as no current guidelines exist. For our patient, virtual bronchoscopy was obtained at baseline with plans for serial follow up.
CONCLUSION:Radiation in combination with chemotherapy has been recommended for treatment of patients with locally advanced stages of lung cancer. Clinicians should be aware that airway metaplasia may become more common as more patients are successfully treated and live longer with radiation as part of their lung cancer treatment regimens, and virtual bronchoscopy may play an increasingly important role in identifying and following this disorder.
DISCLOSURE:Daniel Kim, None.