Chang Y C, Yang P C, Luh K T, Tsang Y M, Su C T
Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
J Formos Med Assoc. 1999 Jun;98(6):440-3.
Pulmonary alveolar microlithiasis (PAM) is a rare disease. It has been reported predominantly in Turkey. We report a case of PAM with characteristic high-resolution computed tomography (CT) findings. A 45-year-old Taiwanese woman had progressive difficulty in breathing for 7 years. Her chest radiographs showed diffuse high-density micronodules and reticular lines that obliterated the bronchovascular bundles and the margin of the heart and diaphragm. The micronodules were scattered throughout both lung fields with basal predominance. Examination of a transbronchial lung biopsy specimen showed PAM. High-resolution CT showed a unique and characteristic calcified reticular pattern and thickening of the interlobular septa of the lung parenchyma, with predominant basal and peripheral lung distribution. Reticulonodular changes of the interlobular septa and intralobular interstitial lines associated with subpleural air cysts and paraseptal emphysema were evident. These high-resolution CT findings are pathognomonic for PAM. Thus, lung biopsy may be avoided in the presence of this characteristic finding.
肺泡微石症（PAM）是一种罕见疾病。主要在土耳其有相关报道。我们报告一例具有特征性高分辨率计算机断层扫描（CT）表现的PAM病例。一名45岁的台湾女性出现进行性呼吸困难7年。她的胸部X线片显示弥漫性高密度微结节和网状线，使支气管血管束以及心脏和膈肌边缘模糊不清。微结节散在分布于双肺野，以肺底部为主。经支气管肺活检标本检查显示为PAM。高分辨率CT显示肺实质小叶间隔增厚及独特的特征性钙化网状模式，主要分布于肺底部和周边。小叶间隔和小叶内间质线的网状结节改变伴有胸膜下气囊肿和间隔旁肺气肿明显可见。这些高分辨率CT表现对PAM具有诊断意义。因此，在存在这种特征性表现时可避免进行肺活检。
