COP Pathology
COP Pathology

Cryptogenic organizing pneumonia (COP) is defined as the unexplained occurrence of a patchy organizing pneumonia accompanied by a mild cellular interstitial inflammatory reaction. The described histopathology is unfortunately quite nonspecific, but in the proper clinical and radiological context, the findings illustrated in this photomicrograph are consistent with the diagnosis of COP. The process tends to be rather patchy in the biopsy sample, evidenced here by tufts and tongues of immature fibroblasts (airspace organization - AO) within alveolar spaces and alveolar ducts.