Background: Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology in which skin involvement is frequent.
Objective: To review histological characteristics of biopsies of specific cutaneous lesions of sarcoidosis and their relationship with clinical course.
Patients and methods: Biopsies from 32 patients with specific cutaneous sarcoidosis were reviewed. Histological findings and clinical characteristics of these patients were analysed.
Results: The initial clinical lesions of the patients were ten infiltrated nodule-plaques, eight papules, four maculopapular eruptions, five scar sarcoidosis, four subcutaneous nodules and one lupus pernio. Sarcoidal granulomas were located at dermis in 31 cases (74%) and at subcutaneous fat in 12 (28%) but only four were subcutaneous exclusively. Perivascular or periannexial distribution of granulomas was observed in eight cases (19%) and they had coalescence in 29 samples. The presence of foreign material was demonstrated in 11 cases (26%).
Conclusions: Clinical spectrum of specific lesions of cutaneous sarcoidosis showed a good correlation with granulomas localization in the biopsies. However, traditional classification of specific cutaneous sarcoidosis is often overlapping. On the other hand, foreign bodies and other atypical histological findings were more common than initially expected.