Micronodular pattern organising pneumonia mimicking miliary lung disease: a rare radiological presentation.

Organising pneumonia (OP) is an interstitial lung disease characterised by granulation tissues in alveoli and alveolar ducts. Typical imaging findings are migratory airspace opacities with peripheral or peribronchovascular distribution. Diffuse micronodular OP (MNOP) is a rare imaging manifestation, which has imaging differential diagnosis of endobronchial infection such as tuberculosis, hypersensitivity pneumonitis and respiratory bronchiolitis. Although clinical and ancillary radiological findings may aid in refining the differential diagnosis, histopathological assessment is frequently required for this rare presentation due to implications of treatment and prognosis. We report a case of MNOP and performed a review of the literature.