Introduction Pulmonary alveolar microlithiasis (PAM) is a rare, chronic lung disease characterised by widespread intra- alveolar calcification of both lungs. The aetiology and pathogenesis of the disease are still unknown. Conse- quently, there is no known effective treatment. In this report, we present the clinical and radiological findings of a 9-year-old girl with PAM after the first year of therapy with disodium editronate, which is known to inhibit the microcrystal growth of hydroxyapatite. Considerable improvement of the calcific densities was shown on chest radiographs and high-resolution computerised tomography (HRCT) scans. Case Report A 9-year-old girl was admitted to Hacettepe University Children’s Hospital because of failure to thrive. There were no positive findings on examination of the chest, and the rest of the physical examina- tion results were normal except for the finding of height and weight being on the 3rd centile. Postero-anterior (PA) and lateral chest radiographs showed fine sand-like opacities with calcific densities throughout both lung fields. The calcified parenchymal densities weremoreprominentalongthepleuralsurfaces.Ablackpleuralline between the bony rib cage and the calcified pulmonary infiltrate was seen on chest radiographs (Fig. 1a). HRCT revealed diffuse ground- glass opacities throughout both lungs with micronodular densities and a few scattered subpleural cysts, representing early manifesta- tion of the fibrotic disease. Interlobular septal thickening, more prominent in the anterior parts of both lungs, and linear calcifica- tions along the pleura were also seen on HRCT scans (Fig. 1c). CASE REPORT Pediatr Radiol (2002) 32: 380–383 DOI 10.1007/s00247-001-0651-x Ug˘ ur O ¨ zc¸elik Meltem Gu¨ lsu¨ n Ayhan Go¨c¸men Macit Arıyu¨ rek Nural Kiper Deniz Anadol Nazan C¸ obanog˘ lu Treatment and follow-up of pulmonary alveolar microlithiasis with disodium editronate: radiological demonstration Received: 4 February 2001 Accepted: 6 November 2001 Published online: 21 February 2002 Ó Springer-Verlag 2002 U. O ¨ zc¸elik (&) Æ A. Go¨ c¸ men Æ N. Kiper D. Anadol Chest Disease Unit, Hacettepe University, Ankara, Turkey E-mail: uozcelik@gen.hun.edu.tr Tel.: +90-312-3243696 Fax: +90-312-3243284 U. O ¨ zc¸elik Yılmaz C¸ olpan 3 sokak 26/2, Oran S¸ehri, Ankara, Turkey M. Gu¨ lsu¨ n Æ M. Arıyu¨rek Department of Radiology, Hacettepe University, Ankara, Turkey N. C¸ obanog˘ lu Department of Paediatrics, Bayındır Medical Centre, Ankara, Turkey Abstract A 9-year-old girl with pul- monary alveolar microlithiasis is presented. She was asymptomatic except for failure to thrive. Plain chest radiographs on admission showed sand-like opacities with cal- cific densities throughout both lung fields, predominantly in the lower zones. A black pleural line was also seen between the ribs and lung parenchyma. High-resolution CT (HRCT) revealed diffuse ground- glass opacities throughout both lungs, micronodular densities, inter- lobular septal thickening, linear cal- cifications along the pleura and a few scattered subpleural cysts. Di- sodium editronate, which is known to inhibit the microcrystal growth of hydroxyapatite, was started at 10 mg/kg per day orally. After 1 year of therapy, considerable re- gression of the calcific densities was detected on chest radiographs and HRCT scans. Keywords Pulmonary alveolar microlithiasis Æ Disodium editronate Æ High-resolution CT Æ Chest radiograph