Histopathological Features of Subcutaneous Sarcoidosis.

Only a few series of patients with systemic sarcoidosis and specific subcutaneous lesions have been reported. We reviewed our patients with systemic sarcoidosis with specific subcutaneous lesions to analyze their histopathological features and their relationship with clinical features of the systemic disease. Patients with systemic sarcoidosis with predominantly subcutaneous sarcoid granulomas diagnosed between 1980 and 2016 in Bellvitge University Hospital were enrolled. We also analyzed patients with clinically and histopathologically identical lesions in whom a diagnosis of systemic sarcoidosis could not be made during follow-up. Twenty-eight patients with systemic sarcoidosis presented specific subcutaneous lesions (23 women and 5 men, mean age 55.64 SD 12.26 years). Dermal involvement was observed in 10 cases, always discrete and limited to deep reticular dermis. The distribution of the granulomatous infiltrate was lobular in 7 cases and lobular and septal in 21. Fibrosis was observed in 21 cases. There were no significant differences in persistence of lesions or persistence of systemic disease activity when comparing patients with and without fibrosis. In conclusion, fibrosis is a frequent finding in subcutaneous sarcoidosis, and although it may be intense, it is not associated with pulmonary fibrosis or with >2 years of persistence of systemic sarcoidosis activity.