Pulmonary Langerhans cell histiocytosis presenting as a solitary nodule

Solitary pulmonary nodules are an uncommon manifestation of pulmonary Lange rhans cell histiocytosis (PLCH). We describe a 45-year-old male cigarette s moker who presented with an asymptomatic solitary pulmonary nodule that sho wed histologic and immunophenotypic characteristics of PLCH. Twenty-one Sea rs after excision of the nodule, at the age of 66 years, he is asymptomatic with a new contralateral lung nodule but no evidence of interstitial disea se. The new nodule has remained unchanged after 36 months of observation. T his case affirms that PLCH can occasionally cause solitary lesions, which s hould not he interpreted as a harbinger of interstitial lung disease. Isola ted PLCH should be included in the differential diagnosis of unusual solita ry pulmonary nodules.