Thyroid involvement in pulmonary Langerhans cell histiocytosis.

A 21-year-old male discovered that his thyroid gland was becoming enlarged in October 2008. Two months later, chest radiography during a routine physical examination revealed an abnormal shadow and he was referred to our hospital for a complete medical examination. He had experienced asthma-like wheezing about once a month for the past 2 years but he was not receiving any medication. He had smoked several cigarettes per day since the age of 20 years old. Physical examination revealed no abnormalities except goiter. Blood analyses showed a white blood cell count of 4,710/μL comprising 47% neutrophils, 42% lymphocytes, 3% eosinophils, and 8% monocytes. Biochemical analysis showed slightly increased levels of serum C-reactive protein (1.30 mg/dL; normal range, <0.20 mg/dL). Thyroid function was decreased (free T4: 0.66 ng/dL; normal range, 0.90-1.70 ng/dL), but antithyroid antibodies were negative. Bone marrow aspirates appeared morphologically normal. Chest radiography revealed reticulonodular infiltration and computed