Disseminated dendriform pulmonary ossification associated with usual interstitial pneumonia: incidence and thin-section CT–pathologic correlation

Abstract

The aim of this work was to assess the incidence of disseminated pulmonary dendriform ossification in usual interstitial pneumonia and nonspecific interstitial pneumonia, and to correlate thin-section computed tomography (CT) and histopathologic findings. We retrospectively reviewed thin-section CT and pathologic specimens of biopsy-proven usual interstitial pneumonia (75 patients, 57 men and 18 women, mean age 60 years, range 29-83 years) and nonspecific interstitial pneumonia (44 patients, 9 men and 35 women, mean age 55 years, range 20-73 years). On review of CT and histopathologic specimens, diffuse dendriform ossification was identified in five (four men and one woman, age range 41-68 years, mean 58 years) of 75 patients (6.7%) with usual interstitial pneumonia. It was not seen in any of 44 patients with nonspecific interstitial pneumonia. With thin-section CT (osteoporosis window; window width 818, level 273), disseminated dendriform pulmonary ossification was detected as multiple tiny calcifications in bibasilar subpleural lungs (100% sensitive and 100% specific when compared with histopathologic findings as the gold standard). The thin-section CT finding of multiple tiny calcifications in bibasilar subpleural lungs might be of some help in the differential diagnosis between usual interstitial pneumonia and nonspecific interstitial pneumonia, considering they were not seen in any patients with nonspecific interstitial pneumonia (0%, 0/44) in our series.

Dendriform Pulmonary Ossification

“…Chest CT has a high diagnostic yield for pulmonary ossification. Kim et al 16 evaluated the incidence of dendriform pulmonary ossification in usual interstitial pneumonia. In this study, 75 subjects were diagnosed with usual interstitial pneumonia by chest CT and open lung biopsy: 5 subjects presented with dendriform pulmonary ossification.…”

Diffuse Pulmonary Ossification in Fibrosing Interstitial Lung Diseases: Prevalence and Associations

“…Definition of DPO.-Because no radiologic definition for the entity of DPO exists (3,11,14,26), we selected two definitions in line with previous descriptions of "bilateral, multiple tiny ossifications or bony nodules," constructed with ease of application in mind. Definition 1 was one or more ossifications that appear bilaterally, with a total of at least 10.…”

“…DPO has been reported in various contexts, including in patients with normal lungs (idiopathic DPO) (4,5); in those with preexisting cardiac diseases, particularly pulmonary congestion secondary to mitral stenosis (6,7); after severe lung injury (8,9); and in association with fibrosing interstitial lung disease (ILD) (10)(11)(12)(13)(14)(15). Previous studies of DPO have been limited by small patient numbers (11,14) or have been based on autopsy studies (1,16) and thus do not provide a clear idea of the frequency of ossification in fibrosing ILDs or its associations. The aims of our study were to determine the prevalence of DPO in patients with different types of fibrosing ILD and to determine whether there are differences among them.…”

High-resolution CT of complications of idiopathic fibrotic lung disease

“…One study found this appearance on HRCT in 5 out of 75 patients with UIP; this corresponded histopathologically to multiple dendriform nodules of mature bone embedded in fibrous stroma in basal, subpleural areas of fibrosis and honeycombing [82]. None of 44 patients with NSIP had HRCT or histopathological evidence of pulmonary ossification, and the authors suggest that, in the context of fibrotic lung disease, HRCT appearances compatible with disseminated dendriform pulmonary ossification may help distinguish UIP from NSIP [82].…”