Cutaneous sarcoidosis in a woman with chronic hepatitis C and interferon therapy: a case report.

BACKGROUND: Sarcoidosis is an autoimmune disease of unknown origin characterized by the presence of noncaseating epithelioid cell granulomas in multiple organs. Sarcoidosislike lesions have been reported in patients who have a history of chronic hepatitis C with interferon treatment. CASE: A case of cutaneous sarcoidosis, clinically presenting with multiple skin nodules, occurred in a woman with a history of relapsed chronic hepatitis C with interferon therapy. Fine needle aspiration biopsy and excisional biopsy showed ill-defined, noncaseating granulomas. On further investigation, the patient was found to have systemic sarcoidosis. Special stains for infectious etiologies were negative. These findings were compatible with morphologic and clinical features seen in sarcoidosislike lesion induced by interferon. CONCLUSION; A nonnecrotizing granulomatous lesion in subcutaneous tissue might have many differential diagnoses, particularly in a cytology specimen. In this condition, understanding of clinical manifestations is critical for diagnosis. It helps practicing cytopathologists to be aware of this phenomenon of cutaneous sarcoidosis occurring in patients with chronic hepatitis C and interferon or antiviral therapies.