Mistaking Reversed Halo Sign with Cavity in Organizing Pneumonia: A Case Report

Organizing pneumonia (OP) is a rare inflammatory lung condition affecting bronchioles and alveoli. Symptoms may include cough, fever, malaise, fatigue, and weight loss with a wide variety of radiological manifestations. Both the unspecific symptoms and the radiological manifestations wide spectrum can make the diagnosis of OP challenging in daily practice. A pathological biopsy is a gold standard for diagnosis. However, there is usually a delay in making the diagnosis as a result of the time that is taken to decide to perform the biopsy. We present a case of OP in which its radiological manifestation first was mistaken for a cavity instead of the reversed halo sign (atoll sign) due to the similarity in some radiological features.