Kashyap Surender, Mohapatra Prasanta R
Department of Pulmonary Medicine, Kalpana Chawla Government Medical College, Karnal, Haryana, India.
Lung India. 2013 Apr;30(2):143-7. doi: 10.4103/0970-2113.110424.
Pulmonary alveolar microlithiasis (PAM) is a rare, chronic lung disease with bilateral intra-alveolar calcium and phosphate deposition throughout the lung parenchyma with predominance to lower and midzone. Although, etiology and pathogenesis of PAM is not fully understood, the mutation in SLC34A2 gene that encodes a sodium-phosphate co-transporter in alveolar type II cells resulting in the accumulation and forming of microliths rich in calcium phosphate (due to impaired clearance) are considered to be the cause of the disease. Chest radiograph and high-resolution CT of thorax are nearly pathognomonic for diagnosing PAM. HRCT demonstrates diffuse micronodules showing slight perilobular predominance resulting in calcification of interlobular septa. Patients with PAM are asymptomatic till development of hypoxemia and cor-pulmonale. No therapy has been proven to be beneficial except lung transplantation.
肺泡微石症（PAM）是一种罕见的慢性肺部疾病，双侧肺实质内出现肺泡内钙和磷酸盐沉积，以下肺和中肺区为主。虽然PAM的病因和发病机制尚未完全明确，但编码肺泡II型细胞中钠磷共转运体的SLC34A2基因突变，导致富含磷酸钙的微石积聚并形成（由于清除受损），被认为是该疾病的病因。胸部X线片和胸部高分辨率CT对诊断PAM几乎具有特征性。高分辨率CT显示弥漫性微结节，略呈小叶周围为主，导致小叶间隔钙化。PAM患者在出现低氧血症和肺心病之前通常无症状。除了肺移植外，尚无已被证明有益的治疗方法。
