Pulmonary ossification: a review

Pulmonary ossification (PO) is a rare disease, especially in patients without a previous history of lung disease. PO has an indolent course that may progressively cause lung function impairment. It is characterized by the presence of ectopic metaplastic bone in the lungs. Although it is generally idiopathic, it may be associated with other diseases, such as interstitial lung diseases. High resolution computed tomography (HRCT) of the chest is the technology of choice for diagnosis, as it allows differential diagnosis with other diseases and spares the use of more aggressive diagnostic techniques. Distinctive radiological findings include two ossification patterns: dendriform and nodular (the most frequent). Each pattern is associated with specific histological findings and can be related to different entities or otherwise be idiopathic forms. This review provides an updated overview of the pathogenesis, diagnostic and histopathological criteria and prognostic factors. As specific treatment is not currently available, the objective is to prevent fibrotic interstitial progression. For a correct management of the disease, it is necessary to consider the associated comorbidities and closely monitor cases. The purpose of this approach is to prevent progression, in case it is associated with diffuse interstitial lung disease. Further research and long-term follow-up are necessary for a better understanding of the pathogenesis and prognosis of PO.