Pulmonary Alveolar Microlithiasis - Report of Two New Cases and Review of the Literature

Abstract

INTRODUCTION: Pulmonary alveolar microlithiasis (PAM) is a rare autosomal recessive disease characterized by the intra-alveolar accumulation of spherical calcified microliths, of a phospho-calcium nature, in the absence of any problem of phosphocalcium metabolism. The majority of patients are asymptomatic. The disease is often diagnosed on routine radiological examination.CASE REPORTS: We report two cases of PAM; A 17-year-old girl with three generations of consanguinity, who consulted for bronchial syndrome. Auscultation revealed very fine diffuse ronchi. The X-ray showed a bilateral alveolar syndrome, especially on the right, a bilateral bronchointerstitial syndrome, and diffuse bilateral calcifications. The thoracic CT scan showed calcified micro and macronodules with thickening of the septa, middle section involvement with fibrosing remodeling, fibrosis, and tractional bronchiectasis of the bases, pleural and pericardial calcifications. Respiratory function tests showed a restrictive syndrome with a vital capacity of 70% and normal GDS. This radiological and scanographic picture made us think of PAM. We then decided to carry out a family investigation with chest radiographs. All family members had normal radiographs, except for a sister who was three years old, with no particular history, no functional respiratory signs, and no particular complaints. Her chest radiograph showed the famous sandstorm appearance of microcalcifications, with pulmonary distension at the apexes and retractions at the bases. Spirometry and blood gases were normal. Chest CT found microcalcifications, with bilaterally distributed and diffuse ground-glass aspects, with a slight right-hand predominance.CONCLUSION: MLA is known to be radio-clinically dissociative. The diagnosis can be made by radiology alone in typical cases; sometimes, Transbronchial or surgical lung biopsies are needed. The prognosis is compromised in the long term. The only effective treatment nowadays is lung transplantation.