A 45 year old male smoker presented with progressive shortness of breath for last 6 months. There was no significant past medical history. Physical examination and all blood tests were normal. Chest X-ray showed non-specific interstitial infiltrates bilaterally. High resolution CT scan was consistent with reticulo-nodular and cystic changes in upper and middle lobes and ground glass appearance in posterior basal lobes of lungs. There was mix obstructive and restrictive pattern on pulmonary function tests. Surgical Lung biopsy was taken which confirmed Pulmonary Langerhans cell histiocytosis. Patient was advised to stop smoking and started on medical management. Unfortunately patient lost follow up and presented again with worsening symptoms and clinical signs of right sided heart failure. Echocardiography and right heart catheterization was performed which showed severe pulmonary hypertension. Patient was started on treatment for pulmonary hypertension which made little symptomatic improvement but his symptoms got worsen over time and is now being considered for lung transplantation.
Learning points/conclusion: Pulmonary function tests may be of normal, obstructive, restrictive or mixed pattern as is the case with our patient. But reduction in Diffusing capacity of Lung for Carbon Monoxide (DLCO) is the most common and earliest abnormality. Pulmonary hypertension is a common and under recognized complication due to direct vasculopathy (arterioles but predominantly venules) and can occur at any time during course of disease as it may or may not co-relate with lung function abnormalities and severity of parenchymal involvement. Investigations for pulmonary hypertension should be done early to prevent unnecessary delay in management.
Waqas Ilyas, Zohaib Tariq