Granulomatous disorders are characterized by the presence of granulomas defined as a focal, compact collection of inflammatory cells in which mononuclear cells predominate. Granulomas form as a result of tissue injury by a wide variety of agents including microorganisms, antigens, chemical, drugs and other irritants. In other situations including sarcoidosis, the etiologic factors remain to be determined. Sarcoidosis Sarcoidosis is a chronic inflammatory disease in which granulomatous lesions can develop in many organs, mainly the lung. Its cause remains obscure, and most likely involves environmental and host factors [119] . The current concept is that a still unknown stimulus activates quiescent T cells and macrophages leading to recruitment and activation of mononuclear cells, with, as a consequence, granuloma formation, alveolitis, and in some cases interstitial lung fibrosis [120] . Sarcoidosis is relatively uncommon among children. Its diagnosis is based on a combination of suggestive clinical features, with histologically-documented noncaseating granuloma, in the absence of other known causes of granuloma formation [121] . The incidence and prevalence of sarcoidosis are reported to be influenced by age, race and geographic localization [122] . Although the youngest patients reported were infants 2 and 3-months old, most of the cases in children occur in preadolescents and adolescents. From the national patient registry on patients with sarcoidosis in Denmark during the period 1979-1994, 81 patients with a confirmed diagnosis were ≤16 years of age [123] . The calculated incidence was 0.29 per 100.000 person-years. In children ≤4 years of age, the incidence was 0.06; it increased gradually to 1.02 in children aged 14-15 years. Marked racial differences in the incidence and prevalence of sarcoidosis have been reported by many authors [122] . Various reports in the literature also indicate that race and ethnicity affect both the patterns of organ involvement and disease severity. In a follow-up study we have conducted in 21 children with pulmonary sarcoidosis, 12 children were Black [124] . Also the number of organs involved was higher in the Black than in the Caucasian children.