[Organizing Pneumonia: Analysis of 10 Years Registers in a Chilean Center]

Organized pneumonia (OP) is an uncommon disease included in the group of idiopathic interstitial pneumonias. It can be cryptogenic (COP) or secondary to various etiologies. Its diagnosis is complex and not standardized. There are no published Chilean series. We present a cohort of patients with pneumonia in organization treated at the National Thoracic Institute (INT).

To describe the characteristics of patients with OP in a Chilean center.

Pathological registries from the INT were reviewed between 2013 and 2022. Clinical and radiological information was obtained from hospital records. Each case was reviewed by the research team. Data are described by means, absolute and relative frequencies.

From an initial list of 203 biopsies, 69 were obtained with clinical/radiological symptoms compatible with OP. The mean age of these subjects was 62 years, of which 33 (47.8%) were men and 36 (52.2%) women. Biopsies were obtained by transbronchial biopsy in 49 (71%) cases and surgical biopsy in 19 (27.5%) cases. In terms of etiology, 37 (53.6%) of them were considered cryptogenic, 12 (17.4%) secondary to the use of medication / drugs and 11 (15.9%) cases associated with connective tissue disease. Regarding treatment, 36 (52.2%) patients received oral steroids and 10 (14.5%) were treated with a mix of corticosteroids and immunosuppressors. In the long-term follow-up, there were 23 deaths in just over 6 years.

The reported series has similar characteristics to those reported in the literature. Most of the cases described in this series were classified as COP. The most common underlying etiologies were connective tissue diseases and medications. The most used treatment was corticosteroid alone or mixed with immunosuppressors.