Neurofibromatosis-Associated Lung Disease: A Case Report

Abstract

INTRODUCTION:Neurofibromatosis type I (NF-1) is a rare disorder that affects multiple organs, with cutaneous findings being the most well-known. It is an autosomal dominant disease caused by dysplasia of ectoderm and mesoderm with variable expression [1]. NF is characterized by a collection of neurofibromas, café au lait spots, and Lisch nodules. Neurofibromatosis is a rare disease and only 10-20% of the cases have associated diffuse lung disease (NF-DLD). Thus, many of the specific characteristics have yet to be elucidated [2].CASE PRESENTATION: A 50-year-old white man with NF-1 diagnosed by skin biopsy 2 years ago was seen by his PCP due to worsening shortness of breath associated with a productive cough. Levofloxacin was ordered, but 5 days later symptoms persisted so he was referred to the ED.He reported a prior tube thoracostomy after spontaneous right-sided pneumothorax.Family history was remarkable for neurofibromatosis in his mother and spontaneous pneumothorax in his brother. However, his brother does not have any of the cutaneous findings consistent with NF.He is a former smoker with a 20 pack-year history, quitting a month before admission. He works in a furniture company with exposure to wood dust and chemical fumes for more than 30 years.He denies any fever, chills, chest pain, or weight change. Denies any sick contacts.Physical examination demonstrated no respiratory distress. He had mild bibasilar crackles and multiple neurofibromas throughout his body, more so on his back. SARS-CoV-2, influenza A, influenza B, RSV PCR were all negative. Chest x-ray demonstrated peripheral interstitial opacities. He was started on empiric antibiotic coverage for community-acquired pneumonia. Chest CT showed evidence of upper lobe predominant cystic disease and pulmonary reticular abnormalities in the lower lobes consistent with neurofibromatosis associated diffuse lung disease. Centrilobular emphysema and mild bronchiectatic changes were also noted. He was started on bronchodilators with a 5day course of prednisone. Respiratory status returned to baseline and he was discharged with a LABAþLAMA inhaler and followup with the pulmonary clinic. DISCUSSION:The exact prevalence of NF-DLD is unknown. Based on the limited case reports, NF-DLD is more predominant in men, occurring during the third or fourth decade of life with dyspnea being the more common presenting symptom. Whether smoking plays a role in NF-DLD is still unknown. The typical HRCT finding in NF-DLD is upper-lobe cystic and bullous disease with basilar interstitial lung disease. HRCT results demonstrate bibasilar reticular opacities 50%, bullae 50%, ground-glass opacities 37%, cysts, and emphysema 25% [3].CONCLUSIONS: NF-DLD is considered one of the rare etiologies of cystic lung disease characterized by upper lobe cystic and bullous disease and lower lobe interstitial changes.