Dendriform pulmonary ossification and pulmonary fibrosis: can progression be slowed?

Diffuse pulmonary ossification is a rare yet under-reported pulmonary finding. It consists of two main types which can coexist in some patients: dendriform and nodular.We present a case report of a middle-aged male who was investigated for breathlessness and diagnosed with Dendriform Pulmonary Ossification (DPO) based on CT imaging. He had a medical history of asthma (well controlled) and symptoms suggestive of obstructive sleep apnoea (OSA). Treatment was subsequently initiated for this. Follow-up of this case revealed an initial decline in pulmonary function tests (PFTs) associated with radiological development of possible Usual Interstitial Pneumonia (UIP) pattern fibrosis with stabilisation of fibrosis and PFTs after treatment of OSA was initiated.Little is known about this rare disease, specifically details surrounding the long-term projection, disease course and outcomes. It has been described as slowly progressive; however, factors contributing to progression have not been specifically identified. There is no current treatment; however, management often focuses on control of comorbidities in patients.We demonstrate one case where it seems that the progression of fibrosis and pulmonary ossification may be potentially slowed by treating the underlying inciting factor. We welcome other cases and long-term follow-up to determine if this hypothesis holds true for the wider population with this rarity. The development of a national registry for this condition would be a useful resource for clinicians and patients alike.