Pulmonary alveolar microlithiasis: an interesting case report with systematic review of Indian literature

Pulmonary alveolar microlithiasis is a rare disease characterized by intra-alveolar presence of microliths. This study reports an interesting case of pulmonary alveolar microlithiasis and provides a systematic review of cases reported from India. A 23-year-old female presented with a history of cough, wheeze, chest pain, and episodic wheeze for five months. Pulmonary function tests demonstrated an obstructive pattern, and chest Xray showed fine micronodular opacities predominantly involving the middle and lower zones of both lungs. Transbronchial lung biopsy revealed the diagnosis. She responded well to inhaled steroid therapy. A systematic review of literature was performed and identified 73 cases of pulmonary alveolar microlithiasis reported from India. The mean (SD) age of the patients was 28.8 (14.9) years, with an almost equal male:female ratio. Many patients were asymptomatic at presentation. Breathlessness and cough were the most common symptoms, and the disease progressed into respiratory failure associated with cor pulmonale. About one-third of the cases were initially misdiagnosed and treated as pulmonary tuberculosis. Extra-pulmonary manifestations and comorbidities were also evident in our series. This systematic review helps to determine epidemiological and clinical characteristics of pulmonary alveolar microlithiasis. Further research is needed to elucidate the etiopathogenesis, diagnosis, and therapeutic options, which are beneficial in developing and identifying cost-effective treatment for pulmonary alveolar microlithiasis.