Dendriform pulmonary ossification associated with idiopathic pulmonary fibrosis

Diffuse pulmonary ossification, a rare condition characterized by metaplastic ossification of the lung, is usually associated with diseases causing diffuse pulmonary lesions. Two types -dendriform and nodular- have been identified. In dendriform ossification, the less common type, osseous ramifications occur along the distal airways, with occasional islets of bone marrow. We report a case of diffuse dendriform pulmonary ossification associated with idiopathic pulmonary fibrosis.' The diagnosis was based on histological examination, which demonstrated multiple nodules and ramified osseous spicules around the lung, mainly at the lower lobes, where the fibrotic lesions were also most evident.