[Rapid remission of pulmonary eosinophilic granuloma in a young male patient after cessation of smoking].

A 24-year-old asymptomatic man was referred to our hospital in October 7, 1997 for further examination of abnormal shadows detected on chest X-ray films that had been obtained during an annual health examination on September 12, 1997. The patient had suffered productive cough since the end of August 1997. A chest X-ray film obtained one year earlier showed no abnormalities. The patient had smoked 20 cigarettes per day since the age of 14. The findings of a physical examination and laboratory tests were unremarkable. A chest X-ray films showed micronodules 2-5 mm in size that were predominantly distributed in the upper and middle fields of both lungs. A chest computed tomogram (CT) showed multiple cysts measuring about 10 mm in diameter, with thick walls (2 to 3 mm) in addition to small nodular shadows. A transbronchial lung biopsy and a thoracoscopic lung biopsy revealed several stellate nodular fibrotic lesions containing some S-100 protein-positive, large mononuclear cells and lymphoid cells. An electron microscopic study found several Langerhans' cells with Birbeck's granules in their cytoplasm. A chest CT scan obtained 2 months after the patient stopped smoking (the day of admission) showed marked regression of the cystic shadows. Evidence suggests the pathogenesis of the disease is closely linked to smoking, and some case reports have documented clinical and radiographic improvements after patients stop smoking. Pulmonary small nodular lesions and cystic lesions with thick walls tend to undergo regression. Although surgical lung biopsy specimens disclosed several stellate nodular fibrotic lesions of eosinophilic granuloma that seemed to be histologically irreversible, our patient experienced remarkable regression of his pulmonary lesions within 2 months after the cessation of smoking.