The clinical characteristics of non-resolving or slow-resolving pneumonia associated with the pathology of an organizing pneumonia

Park, Seoung Ju; Paeck, Kyung Hyun; Choe, Yeong Hun; Kim, So Ri; Lee, Yong Chul; Rhee, Yang Keun; Jin, Gong Yong; Lee, Heung Bum

Abstract

BACKGROUND/AIMS: Non-resolving or slow-resolving pneumonia refers to the persistence of pulmonary infiltrates for >30 days after an initial pneumonia-like illness. Organizing pneumonia (OP) can be found on a lung biopsy in association with a number of diseases. The object of this study was to elucidate the clinical characteristics of the non-resolving pneumonia with the pathology of an OP and suggest the proper diagnostic and therapeutic approaches for the reduction of unnecessary procedures.
METHODS
We retrospectively analyzed 70 patients diagnosed with an OP by percutaneous transthoracic needle biopsy and that met the inclusion criteria. Their pulmonary lesions were reviewed for disease resolution. Patients were divided into either a radiologically benign group (group I, n=57) or a malignancy group (group II, n=13) based on the computed tomography (CT) findings.
RESULTS
All patients in group I and 8 patients in group II improved and had a complete resolution by 81.70+/-45.36 days. The microbiology findings showed that many infectious pathogens can lead to an OP despite antibiotic therapy. Three cases in group II were ultimately diagnosed as malignancies.
CONCLUSIONS
Our data suggest that non-resolving or slow-resolving lesions were strongly suspicious for a malignancy on the CT scans, despite appearing to be benign OP pathologically; such cases should be considered for re-biopsy. In cased with pathology consistent with OP and benign CT findings, careful observation for 3 months is recommended to allow for the complete radiological resolution of the benign OP associated with infection.