Idiopathic focal organizing pneumonia mimicking malignancy

Idiopathic FOP is a rare type of COP. What we know on this subject is made up of a few clinical cases published in recent years. Our patient was admitted to the hospital with an intermittent coughing complaint that worsens over time. Due to a suspicion of malignancy, a radiological evaluation was requested including a PET-CT and a transbronchial biopsy was performed. Until the last part of our algorithm, the patient profile was clinically and radiologically in favor of the diagnosis of malignancy but, in the end, the diagnosis of FOP was fixed with a follow-up decision. In conclusion, FOP is a relatively new entity that should be kept in mind in the differential diagnosis of malignancy.