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 file 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 findings, 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 infiltrates scattering in the dermis, but one biopsy revealed a leprosy-like linear granuloma. Other significant histological findings 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 identified 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 find naked granuloma is warranted. Other histologicalal findings, such as collagen degeneration, elastophagocytosis and linear peri-neural granuloma, may mislead us into diagnoses like granuloma annulare, actinic granuloma, and leprosy respectively.