[Involvement of the lungs in neurofibromatosis]

Two patients, a 66-year-old man (case 1) and a 55-year-old woman (case 2), had been known (for 40 and 35 years, respectively) to have type 1 neurofibromatosis. Dyspnoea, recently even at rest, had developed in both over the past few years. Both were emaciated (weight 62 kg, height 180 cm; 42 kg, 166 cm, respectively). In both the chest radiography had net-like increased interstitial markings. Computed tomography in case 1 showed largely subpleural small-blister-like changes bilaterally (honeycomb lung), while there were large apical cysts bilaterally in case 2. Lung function tests demonstrated restrictive changes in case 1 (vital capacity 48% of norm, relative one-second capacity 88%) and severe ventilation abnormality in case 2 (vital capacity 42% of norm, relative one-second capacity 47%). Both had marked hypoxaemia even at rest and the walking limit was 200 m in case 1, 40 m in case 2. The pulmonary changes were most likely manifestations of the neurofibromatosis. Symptomatic treatment consisted of long-term oxygen therapy with a portable liquid oxygen system (flow rate: 1-2 l/min at rest and 3-5 l/min on exercise; duration: 24 h/d). This achieved a walking distance without hypoxaemia of 500 and 200 m, respectively, with marked improvement in the patients' condition.