Solution: Most patients with Pulmonary Alveolar Microlithiasis are asymptotic at diagnosis. There is an equal gender distribution. As the disease progresses the patient often develops dyspnea on exertion. Pulmonary fibrosis, cor pulmonale and respiratory insufficiency may result with severe involvement. Pathogenesis remains unknown. An inborn error of metabolism is suggested by the high rate of occurrence within families (>50%) and it is thought that it might be autosomal-recessive. This disease is characterized by the presence of numerous tiny calculi (calcispherytes). Chest X-ray usually demonstrates a fine sandlike micronodular pattern diffusely involving both lungs with greater involvement at the lung bases. Generally progressive with no good treatment.