Cryptogenic Organizing Pneumonia
50 yo M with pmhx of RA (on methotrexate and prednisone chronically) and decubitus ulcers presenting with 2 weeks of cough and malaise. He was also found to be hypotensive and hypoxic. Infiltrates were seen on CXR and treatment for HCAP was initiated (had many exposures to healthcare settings in past). After several days of treatment, little improvement was noted in his hypoxia.
Normal sputum cultures were negative. Bronchoscopy did not show any organisms, including AFB or positive DFA for PCP. At this point, other non-infectious etiologies were considered and it was decided to pursue a lung biopsy via VATS. Several days later, biopsy showed evidence of “organizing pneumonia” and patient was diagnosed with COP (cryptogenic organizing pneumonia).
“Organizing pneumonia” is a histopathologic diagnosis that can have multiple etiologies. In this patient’s case, the etiology was thought to be due to his rheumatoid arthritis or potentially from his methotrexate (which was discontinued). Unfortunately there was not much improvement after initiation of high doses of steroids so the patient’s prognosis remains uncertain.
Here is a link to a fantastic review of COP in the European Respiratory Journal (beware printing it, because the paper is 25 pages long and has 13 pages of references.