Small duct autoimmune sclerosing cholangitis and Crohn colitis in a 10-year-old child. A case report and review of the literature

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1418596609736470 webciteImmune-mediated liver diseases fall into two broad categories, those with a hepatitic predominance: autoimmune hepatitis (AIH), and those with a predominance of cholestatic features: primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). AIH is characterized by elevated serum aminotransferases, hypergammaglobulinaemia (primarily immunoglobulin G), circulating autoantibodies (primarily antinuclear antibodies (ANA) and smooth muscle cell antibodies (SMA)) and interface hepatitis on liver biopsy specimen, while markedly elevated serum alkaline phosphatase (ALP), circulating antimitochondrial antibodies (AMA), or biliary changes on liver biopsy specimen are normally not present [1]. In contrast, PBC and PSC are characterized by cholestatic biochemistry, occurrence of AMA (PBC only), and histological biliary changes such as granulomatous cholangitis (PBC only) or fibroobliterative cholangitis (mainly PSC), leading to ductopenia and biliary cirrhosis. However, PBC and PSC may also reveal features of AIH, which are sufficiently pronounced to qualify for so-called overlap syndromes, even though there are no established definitions for these [2]. A scoring system established by the International Autoimmune Hepatitis Group (IAIHG) for research purposes [1] has been widely used in the clinical practise to classify patients as having “definite AIH”, “probable AIH” or “not AIH”. The scoring system is, however, not directly applicable for overlap syndromes.The AIH/PSC overlap syndrome, also designated autoimmune sclerosing cholangitis (AISC) is occasionally seen in adults [2-4], but more often occur in children, where up to about 50% of patients presenting with AIH reveal radiological features of cholangiopathy [5]. Even among AIH patients with normal cholangiogram, histological biliary changes have been found in about 30% [5]. In other