Pulmonary Alveolar Microlithiasis
Differential Diagnosis
| Pulmonary Alveolar Microlithiasis |
Pulmonary Blue Bodies |
| Most are 250-750 microns |
Most are 15-40 microns |
| Most alveoli filled |
Usually few and scattered, alveoli not filled |
| Autosomal recessive |
Many cases associated with pneumoconiosis or interstitial lung disease |
| Pulmonary Alveolar Microlithiasis |
Pulmonary Corpora Amylacea |
| Calcified |
Not calcified |
| Most alveoli filled |
Usually scattered, alveoli not filled |
| Autosomal recessive, mean age of symptoms 30 years |
Increased numbers with aging, asymptomatic |
| Pulmonary Alveolar Microlithiasis |
Metastatic Calcification |
| Restricted to alveolar air spaces |
May involve air spaces, interstitium, bronchial walls |
| Spherical and laminated |
Irregular calcification |
| Autosomal recessive |
Associated with renal failure, parathyroid carcinoma |
| Pulmonary Alveolar Microlithiasis |
Heterotopic Ossification |
| Restricted to alveolar air spaces |
Interstitial |
| Spherical and laminated |
Lamellar spicules of bone |
| No cellular component |
Osteocytes in lacunae |
| Autosomal recessive |
Associated with prior inflammation |
