Pulmonary alveolar microlithiasis with finger clubbing: A case report and literature review

Pulmonary alveolar microlithiasis (PAM) is a rare autosomal recessive and slowly progressive disease. Mutations of the solute carrier family 34, member 2 gene are considered to be the cause of the disease. The present study reported the case of a 35-year-old female patient who was diagnosed with PAM. The parents of the patient were reported to be blood-related (cousins). The clinical manifestations and radiological and pathological characteristics of the patient are reported. A pulmonary function examination detected restrictive ventilatory and diffusion defects, and a high-resolution computed tomography scan showed multiple bilateral diffuse ground-glass opacifications and subpleural linear calcifications. A bronchoalveolar lavage fluid (BALF) examination detected a calcified body in the lavage fluid and a transbronchial biopsy showed numerous calcified bodies, concentrically laminated with an onion skin-like appearance in the alveolar spaces. Based on the aforementioned observations, the patient was diagnosed with PAM. Following administration of inhaled corticosteroid treatment, the symptoms were improved and the patient was discharged. After 1 year, the patient was lost to follow-up. The present study presents and reviews the typical radiological appearance, clinical presentation, pathological characteristics and treatments of PAM, and suggests that, often, the parents of the patients are blood-related and typically cousins. In addition, the present study proposes that a BALF examination may be considered an alternative method for the pathological diagnosis of PAM.