University of Connecticut Health Center Plantsville, CT, United States
Teresa Da Cunha, MD1, Saverio Ligato, MD2, Roopjeet K. Bath, MBBS1 1University of Connecticut Health Center, Farmington, CT; 2Hartford Hospital, Hartford, CT
Introduction: Small-duct primary sclerosing cholangitis (sdPSC) is rare, characterized by microscopic inflammation and scarring of the intrahepatic bile ducts leading to cholestatic liver disease. It most commonly affects middle aged adults; the overall incidence and natural history of the disease are not well described. We report a case of a young man in whom the time from presentation to diagnosis of small-duct PSC was challenging.
Case Description/Methods: A 26-year-old man with a history of ADHD and depression was referred to gastroenterology for evaluation of longstanding abnormal liver enzymes. He was asymptomatic and denied any abdominal pain, nausea, vomiting, changes in bowel movements, pruritus or weight changes. Initial laboratory tests showed AST 59, ALT 103, GGT 94, ALP 138, TBili 1, INR 1.5, PLT 235. Work up revealed ANA 1:160, ASMA 1:40 but negative LKM1, soluble liver antigen, AMA, celiac panel, and viral hepatitis serologies. Total IgG, IgG4, C4, C3 levels were normal. A prior liver biopsy from 2014 showed nonspecific mild portal and minimal lobular chronic inflammation comprised of lymphocytes, plasma cells and mild fibrosis. MRCP was unremarkable. Given positive ANA/ASMA with concern for possible autoimmune hepatitis he was previously treated with budesonide and ursodiol. Five years later he was diagnosed with ulcerative colitis and was started on prednisone 40 mg daily. Due to persistent elevated liver enzymes, he had a repeat liver biopsy in 2021 that showed chronic portal tract inflammation with mild bile duct atrophy and focal damage, early bile ductular reaction and mild portal fibrosis, consistent with sdPSC.
Discussion: The rare incidence of sdPSC has made it difficult to understand the pathophysiology of the disease. Patients can be asymptomatic or present with fatigue and pruritus. There is a strong association with inflammatory bowel disease (IBD) with a prevalence of up to 88%. Usually, IBD is diagnosed earlier than sdPSC but in this case the abnormal LFTs were seen years before his first IBD flare. The diagnosis requires histologic findings suggestive of PSC with normal cholangiogram. In this case the first liver biopsy revealed nonspecific inflammation. Similar to PSC, ursodiol is the main treatment, however sdPSC seems to have a better prognosis with lower incidence of cholangiocarcinoma. sdPSC is a slow progressive disease that can remain undiagnosed for a long time and may precede the diagnosis of IBD. Serial liver biopsies might be necessary for a conclusive diagnosis.
Figure: Fig 1-3: Sections show hepatic parenchyma with mild portal inflammation, comprising lymphocytes, histiocytes and scattered eosinophils, without plasma cells. There is multifocal absence of bile ducts with ductular proliferation and occasional ductal changes compatible with damage (hyperchromasia, mild nuclear variability, and occasional intraepithelial lymphocytes). There is focal-mild lobulitis and focal occasional hepatocyte necrosis near portal tracts. Portal veins appear mildly dilated, without significant sinusoidal dilatation or thrombosis. There is minimal (2%) macrovesicular steatosis.
Teresa Da Cunha indicated no relevant financial relationships.
Saverio Ligato indicated no relevant financial relationships.
Roopjeet Bath indicated no relevant financial relationships.
Teresa Da Cunha, MD1, Saverio Ligato, MD2, Roopjeet K. Bath, MBBS1. P1849 - Small Duct Primary Sclerosing Cholangitis: A Difficult Diagnosis, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.