Histological Analysis of 10 Cases of Cutaneous Sarcoidosis in Taiwan

Naked sarcoidal granulomas are supposedly characteristic, but not pathognomonic of sarcoidosis. Other types of histopathological pattern can also happen in sarcoidosis and may lead to misdiagnosis. Thirteen archival skin specimens taken from 10 patients were retrieved from our fi le for study. All patients were labeled as sacroidosis based on histological evidence of noncaseating granuloma found in skin or conjunctival biopsies, characteristic chest x-ray fi ndings, and lastly excluding other causes. All cases showed naked sarcoidal granulomas while additional tuberculoid granuloma was identifi ed in one case. Twelve biopsies showed multiple nodular infi ltrates scattering in the dermis, but one biopsy revealed a leprosy-like linear granuloma. Other signifi cant histological fi ndings included collagen degeneration (6/13), elastophagocytosis (1/13), linear peri-neural granuloma (1/13), and mucin deposition (1/13). There were no birefringent foreign bodies identifi ed in any biopsy. In conclusion, tuberculoid granulomas can occasionally happen in sarcoidosis. If sarcoidosis is strongly suspected in clinical settings, a second biopsy from different site to fi nd naked granuloma is warranted. Other histologicalal fi ndings, such as collagen degeneration, elastophagocytosis and linear peri-neural granuloma, may mislead us into diagnoses like granuloma annulare, actinic granuloma, and leprosy respectively. (Dermatol Sinica 26: 228-235, 2008)