Langerhans cell histiocytosis of the lung with probably skeletal involvement

Langerhans cell histiocytosis is characterized by abnormal accumulations of large mononuclear cells forming granulomas in various organs mainly in the lung, bone, or skin. Adult pulmonary Langerhans cell histiocytosis is rare and almost always associated with cigarette smoking; combination with lung and bone simultaneous involvement is even rare. We present a 41 years old male smoker who was diagnosed with pulmonary Langerhans cell histiocytosis by a lung biopsy and manifestations at high resolution computed tomography of the lung. Later technetium-99m methyl diphosphonate bone scintigraphy showed multiple abnormal tracer accumulation of the radiotracer in the skull and a singular focus in a rib.