Fibrotic Sarcoidosis Mimics Non-specific Interstitial Pneumonia: A Case Report

Aims: Fibrotic sarcoidosis is not common presentation and it is not easy to diagnose for many differential diagnosis. We herein report an interesting fibrotic sarcoidosis who shows atypical presentation such as progressive dyspnea with fibrotic imaging findings.

Presentation of Case: A 75-year-old Japanese lady visited our hospital with fifteen months　duration of non-productive cough and one month exertional dyspnea. Physical examination revealed bilateral fine crackles and squawk at left lung base. Laboratory findings showed elevation of lactate dehydrogenase (LDH) and Krebs von den Lungen-6 (KL-6). Chest high-resolution computed tomography (HRCT) showed mediastinal lymphadenopathy, left lower lung field dominant reticular shadow and traction bronchiectasis. In terms of pulmonary function test (PFT), percent predicted vital capacity (%VC), forced vital capacity (FVC) and percent predicted forced vital capacity (%FVC) were 71.2%, 1.12L and 52.8%, respectively. Based on clinical course, laboratory findings and chest imaging, we considered possibility of fibrotic non-specific interstitial pneumonia (f-NSIP).She undertook video-assisted thoracoscopic surgery (VATS). Specimens were taken from left upper lobe and lower lobe. Pathological findings showed well-formed peri-lymphatic granuloma, architectural destruction with dense fibrosis and microscopic honeycombing. According to the clinical-radiological-pathological discussion, we diagnosed this case as fibrotic sarcoidosis. We commenced oral prednisolone 30 mg/day, treatment response was good including clinical symptoms, laboratory biomarker and chest imaging findings. She is well on prednisolone 2.5 mg/day now.

Discussion: This case show similar presentation of f-NSIP both clinically and radiologically. Multidisciplinary discussion was useful for decide to commence adequate management.

Conclusion: We present a fibrotic sarcoidosis patient who mimics f-NSIP.