Pulmonary Alveolar Microlithiasis: A Case Report with Emphasis on Imaging Findings

Abstract

Pulmonary alveolar microlithiasis (PAM) is a rare disease characterized by the presence of small calculi in the alveolar space. The authors report a case of a 21-year-old man with a 2-year history of shortness of breath on exertion and dry cough. Physical examination was altered only for crackles at auscultation. Pulmonary function revealed a mild restrictive ventilatory defect and the chest radiograph demonstrated paracardiac confluence of dense micronodular infiltrate. High-resolution CT scan revealed diffuse ground glass attenuation and septal thickening, more pronounced in lower pulmonary regions, with calcifications along the interlobar septa and subpleural regions. A transbronchial lung biopsy confirmed the diagnosis of PAM.

First Presentation of a Case of Pulmonary Alveolar Microlithiasis with Spontaneous Pneumothorax

“…In addition, which are responsible for "black pleura" sign seen in chest X-rays. 3,5,6 As a diagnostic method, HRCT of the chest has greater sensitivity than a chest X-ray. HRCT findings in patients with PAM vary considerably, nevertheless, the most common findings are ground glass opacities and diffuse calcified nodules.…”

“…[1][2][3] However, its exact pathogenesis is still unknown. The clinical features may vary and patients may be asymptomatic for a long period of time with subsequent occurrence of dyspnea, dry cough, and chest pain, leading to cor pulmonale.…”

Pulmonary Alveolar Microlithiasis :

“…. However progression of disease is slow and mostly death occur from respiratory failure due to cor pulmonale (Abdalla et al, 2010). …”

Diffuse pulmonary ossification in a patient exposed to silica

“…Finally, PAM is characterised by deposition in the alveoli of spherical calcium phosphate concretions (microliths or calcipherites) without bone marrow [3]. In this disease, patients may remain asymptomatic for many years but do usually become symptomatic between the third and fourth decades [4]. In some patients, it progresses into pulmonary fibrosis, respiratory failure and cor pulmonale.…”

“…In some patients, it progresses into pulmonary fibrosis, respiratory failure and cor pulmonale. Typical complaints are dyspnoea, nonproductive cough, chest pain and asthenia [3,4]. High attenuation of lung parenchyma caused by calcipherites, even smaller than 1 mm, is visible on high-resolution computed tomography (HRCT) with a gradient of distribution of the calcifications, in which the lung bases, especially the posterior, are more affected than the middle or upper zones, with a greater concentration in the subpleural parenchyma and along the bronchovascular bundles, whereas HRCT shows thickening of the lobular septa with a distribution of microliths along the septa and around the centrilobular distal bronchioles [5].…”