SinSarcoidosis as a complication ofinterferon (IFN) administration was first described in 1987 in a patient with renal cancer (I). Since then, more than 50 cases of pulmonary and/or cxtra-puhnonary sarcoidosis. mainly occurring in middle-aged women, have been correlated with IFN-a therapy, sometimes associated with ribavirin, in patients with chronic viral hepatitis C (2.3). Several lines of evidence suggest that HLA class I and class II alíeles may be considered possible markers for susceptibility, clinical behaviour and prognosis of sarcoidosis (4, 5).We report here a case of scar sarcoidosis that occurred one month after completion of a course of pegylatedlFN-a therapy for chronic hepatitis C virus (HC V) infection. HLAtyping was perfomied to evaluate the potential role of an immunogenetic predisposition factor.
CASE REPORTA 59-year-old woman was evaluated for a paitiless nodule that had developed slowly on her right foreami over the previous 2 months. Physical examination revealed a well-demarcated, hard, .subcutaneous nodule. 4 cm in diameter, underlying a linear posttraiimalic scar acquired during childhood (Fig. I ). The patient had previously undergone a 24-week treatment for active chronic HCV genotype 2a/2c, consisting of 180 |.ig of PEG-lFN-a, administered subcutaneously once weekly, and 800 mg/day of oral ribavirin. This treatment had had a successful outcome, leading to an undetectahle viral load and an improvement in the results of liver enzyme tests by the tburth week of therapy. The treatment was completed one month prior to the appearance of the nodule.The nodule was surgically removed and the specimen was stained with haematoxylin and eosin. Histopathologiea! examination revealed the presence of Langhans giant ceils and sarcoidal-type, non-necrotizing, round, epithelioid granulomas in both dermis and hypodermis. cireumseribed by peripheral fibrosis (Fig. 2).The patient showed neither pulmonary symptoms nor other signs of systemic sarcoidat involvement. Chest X-ray and angiotensinFig. I. Subcutaneous nodule underlying a linear post-traumatic scar on the right forearm.