Characteristics of patients with a diagnosis of sarcoidosis: a comparison of the 2006 and 2015 versions of diagnostic criteria for sarcoidosis in Japan

Objective: Histological verification of epithelioid cell granuloma is important in diagnosing sarcoidosis; tissue sampling is a worldwide requirement. In 2006, to reduce medical expenses and avoid invasive procedures, diagnostic criteria without histological verification were permitted by the Japanese government. In 2015, new diagnostic criteria, allowed clinical diagnoses based on only respiratory, ocular, and cardiac systems with at least a two-system involvement, increasing the need to sample tissue from clinically unevaluable organs in suspected sarcoidosis. This study aimed to compare the characteristics of patients who were diagnosed with sarcoidosis according to the 2006 and 2015 criteria. Materials and Methods: Using the 2015 version, we re-evaluated the characteristics of 264 patients with diagnosed or suspected sarcoidosis according to the 2006 criteria, at Jichi Medical University Hospital between 2004 and 2012 (clinical diagnosis, 84; histological diagnosis, 117; suspected sarcoidosis 63). Results: Thirty-nine patients were diagnosed with suspected sarcoidosis due to the absence of at least a two-system involvement; two patients had insufficient laboratory data suggestive of sarcoidosis. Six patients moved from suspected sarcoidosis to a histological diagnosis because of a greater leniency in the criteria for supportive findings. The 2015 diagnostic criteria excluded patients with organ involvement without a requirement for systemic steroids from the clinical diagnosis group. A case of schwannoma, erroneously placed in the clinical diagnosis group by the 2006 criteria, was reclassified according to the 2015 criteria. Conclusion: The 2015 version is preferable for clinically diagnosing sarcoidosis, even without histological specimens, and provides guidance for indications for systemic treatment.