“Sandstorm” image: bone scintigraphy in pulmonary alveolar microlithiasis

Abstract

Pulmonary alveolar microlithiasis (PAM) is a rare idiopathic disorder, usually with familial association, leading to alveolar deposition of calcium phosphate microliths. A 48-year-old female patient was referred to our clinic for bone scintigraphy because of severe osteoporosis (L1-L4 T score was -3, 5 ; serum calcium values and 24 h calciuria in normal range). Bone scintigraphy showed bilateral, intense pulmonary 99m Tc-methylenediphosphonate uptake, which brought up us to clinical suspicious of PAM. Chest radiograph revealed extensive, bilateral micronodular sandlike appearance, predominantly in the lower lung fields. The diagnosis of PAM was confirmed by transbronchial lung biopsy. Although bone scintigraphy finding is sometimes negative in the early stage of PAM, this imaging method could be very useful in the detection of PAM.