Diffuse Pulmonary Ossification: an Uncommon Incidental Autopsy Finding

Aim: To determine the incidence of diffuse pulmonary ossification (DPO) and its subtypes at autopsy and correlation with clinical and histological features.

Methods: Autopsy reports from our institution over a 64-month period were reviewed for findings of DPO. The pattern of ossification, demographics and clinical data were obtained from both paraffin sections and final autopsy reports. In a selected case, chest radiograph and wet tissue were obtained.

Results: Seventeen histologically confirmed cases of DPO were found in 10,426 autopsy cases, representing an incidence of 1.63 cases/1000 autopsies. There was a predilection in males (88%) and underlying pulmonary disease (88%). In contrast to published studies, dendriform DPO was more common than the nodular type in our cohort (11 and 6 cases, respectively). The dendriform type was more commonly associated with marrow elements.

Conclusions: Diffuse pulmonary ossification is uncommon and rarely diagnosed during life, but can easily be identified when sectioning the lungs at autopsy. There is recent renewed interest in diagnosing and determining the significance of DPO using high resolution computed tomography and thoracoscopic biopsy.