Pulmonary alveolar microlithiasis (PAM) is a rare idiopathic disorder, usually with familial association, leading to alveolar deposition of calcium phosphate microliths [1, 2].

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 99mTc-methylenediphosphonate uptake, which led us to clinical suspicion of PAM. The chest radiograph revealed extensive, bilateral micronodular sand-like appearance, predominantly in the lower lung fields [3].

The diagnosis of PAM was confirmed by transbronchial lung biopsy.

Although the bone scintigraphy finding is sometimes negative in the early stage of PAM [4], this imaging method could be very useful in the detection of PAM.