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

Abstract

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.

MSC from fetal and adult lungs possess lung-specific properties compared to bone marrow-derived MSC

“…Theoretically, this might be an advantage when developing cell therapies for solid organs like the lung where ossification should be avoided. In fact, calcification and bone formation, although not normally occurring in lung tissues, have been described in very rare conditions, such as pulmonary alveolar microlithiasis (PAM), diffuse pulmonary ossification (DPO) and ossification in carcinoid tumors 6 7 8 . Adult lung MSC secreted significantly higher amounts of the cytokine MCP-1, which is known to be important for innate immunity by attracting monocytes.…”

Pulmonary Alveolar Microlithiasis

“…In general, steroid hormone therapy appears to be ineffective for PAM, though a few authors have reported subjective improvement in some patients 62,63 .…”

Pulmonary alveolar microlithiasis

“…Inhaled corticosteroid therapy does not appear to improve radiographical manifestations of PAM. It has been used effectively to treat symptoms and abnormal lung function in PAM patients who present with accompanying conditions such as spirometrically proven obstructive lung disease suggestive of asthma, lymphocytic interstitial pneumonitis and discoid lupus erythematosus among others [97][98][99], but there is little evidence to support routine inhaled corticosteroid use in patients with PAM.…”