Cystic lung disease in an adult non-smoker.

A 33-year-old non-smoking male who was a farmer by trade and had no other comorbidities presented with complaints of shortness of breath, left sided chest pain and dry cough which had bothered him for over the past 7 days. Past history was insignificant. The patient had tachycardia, tachypnoea (30/min) and oxygen saturation of 88%. There was no clubbing or cyanosis. Chest examination was suggestive of bilateral decreased air entry. A CT examination of the chest was performed (Figure 1A, B). Bilateral intercostal chest tubes were inserted and the patient was given oxygen support. Due to refusal by the patient to perform a surgical lung biopsy, a trans-bronchial lung biopsy (TBLB) (Figure 1C, D) was performed. The patient had bilateral leaks in intercostal chest tubes. When negative suction to both sides was applied, successful cessation of the air leaks was observed. As the CT thorax was suggestive of bilateral pneumothorax with underlying cysts predominantly in upper and mid zones, few nodular opacities, and sparing of costophrenic recess, a provisional diagnosis of pulmonary Langerhans cell histiocytosis (pLCH) was suspected. Transbronchial lung biopsy was suggestive of interstitial fibrosis with a collection of Langerhans cells that had prominent nuclei with CD1a positivity. Thus, the diagnosis of pLCH was made on the basis of clinico-radiological, histopathological and immunohistochemical grounds. According to an expert panel, definitive diagnosis of pLCH requires either microscopic evidence of Langerhans cells with CD1a positivity or Birbeck granule visualization on electron microscopy [1]. A detailed history of polyuria, polydipsia, headache, bone pains, diarrhoea, weight loss, enlarged lymph nodes, oral/skin lesions and/or genital ulcers was negative. Liver function tests, a routine examination of urine for sugar and proteins, ultrasonography of the abdomen and pelvis, a CT examination of the head, and a skeletal scintigram (bone scan) were all normal.