[Do all cryptogenic organizing pneumonias require lung biopsy and steroid treatment?]

Introduction: Diagnostic guidelines recommend a lung biopsy to make the diagnosis of cryptogenic organizing pneumonia (COP). However, in some cases, in the presence of a typical clinical picture, the diagnosis can be made without histological proof: the combination of a "reversed halo sign" and migratory areas of patchy alveolar consolidation on the CT-scan is strongly suggestive. Steroids are the recommended treatment, but relapses and complications of steroids occur frequently whereas the morbidity of COP is usually low and the evolution is often the same with or without treatment.

Case report: We report the case of a 51 year old woman with mild COP. The diagnosis was made according to the clinico-radiological criteria that we propose, without any formal histological proof. Treatment consisted of a short course of steroids, which led to spectacular clinical and radiological improvement but was withdrawn due to poor tolerance. The patient refused further treatment but clinical progress was favourable. After a follow-up period of 2.5 years a CT-scan showed evidence of a radiological relapse but the patient remained asymptomatic.

Conclusion: In this article, we do not attempt to prove that lung biopsy and steroid treatment are unnecessary in the management of COP, but we would like to propose that, in some situations with the coexistence of a "reversed halo sign" and migratory areas of patchy consolidation on the CT-scan, in the context of a typical clinical presentation and mild symptoms, the usefulness of lung biopsy and steroid treatment is debatable.