Cryptogenic Organizing Pneumonia with Sarcoidosis Overlap: An Atypical Case Study

CASE SUMMARY: We present a case of a young female with subacute symptoms of cough and progressive dyspnoea. On evaluation, the patient was diagnosed as cryptogenic organizing pneumonia based on her histopathological reports. However, her significant elevation of serum angiotensin-converting enzyme (SACE) levels which drop after treatment with oral steroids, relapse, and clinical presentation pointed towards sarcoidosis as clinical diagnosis. DISCUSSION: Here, in this patient, transbronchial biopsy was suggestive of cryptogenic organizing pneumonia along with chest X-ray, and the HRCT finding was also favouring the same. But in this case, we have also seen elevated levels of serum ACE which dropped significantly to the normal level along with a complete clearance of lesions with systemic steroids, and this favours sarcoidosis. Also, the recurrence was in different areas of the lung, and lesions once again responded both clinically and radiologically to steroids with a consistent drop in serum angiotensin-converting enzyme (SACE) levels, which again is a feature common in sarcoidosis. In COP, often complete clearance of the lesions is seldom seen, even though they do respond to steroids but not as dramatically as in our case. Also, recurrence of the lesion with BOOP at different sites is uncommon as it generally progresses in the same site. CONCLUSION: This case report suggests that sarcoidosis as a possible cause of cryptogenic organizing pneumonia is worth considering with the mixed spectrum of presentation as in our case. And to our knowledge, this type of presentation of cryptogenic organizing pneumonia with sarcoidosis as an overlap disease is very rare, and this possibility needs to be explored by more series of such cases.