Clinical and pathological analysis of eight cases of subcutaneous sarcoidosis

Objective To investigate clinical and histopathological features of subcutaneous sarcoidosis. Methods A retrospective analysis was performed. Clinical and pathological data were collected from 8 patients diagnosed with subcutaneous sarcoidosis in Hospital for Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College between 2012 and 2018, and analyzed retrospectively. Results Out of the 8 patients, 1 was male and 7 were female, with an average onset age of 50.5 years. The main skin manifestations were multiple painless skin-colored subcutaneous nodules, with no history of trauma or ulceration. Other skin lesions included erythema in 1 case and dark-purple plaques in 1 case. Lung involvement was detected in 6 cases, and no other systems were involved. Histopathological findings were mainly non-caseating granulomas in the subcutaneous tissue with negative acid-fast staining. Of the 8 patients, 7 received short-term oral glucocorticoid treatment and achieved remission or subsidence of lesions, 1 patient was lost to follow-up. Conclusions Subcutaneous sarcoidosis initially manifests as painless skin-colored subcutaneous nodules, which can be complicated by erythema, plaques and so on. Histopathological findings are characterized by non-caseating granulomas. Chronic and mild systemic involvement, especially lung involvement, is common in patients with subcutaneous sarcoidosis, and the prognosis is quite favorable. Key words: Sarcoidosis; Skin manifestations; Pathologic processes; Treatment outcome; Prognosis; Subcutaneous sarcoidosis