Usually stratified squamous epithelium but cuboidal or transitional-like epithelium may be present Dense distinct band of lymphoid tissue • Other elements variably present • Adjacent pancreas is often unremarkable Top Differential Diagnoses…
Numerous species widely present in environment; worldwide distribution – Transmission typically by inhalation or ingestion Mycobacterium avium and Mycobacterium intracellulare, known together as Mycobacterium avium-intracellulare complex (MAC), most commonly cause hepatic…
3 forms: Perihilar, distal, and diffuse • Klatskin tumor: Perihilar tumor occurring at confluence of right and left hepatic ducts Etiology/Pathogenesis • Numerous risk factors, including developmental anomalies, flukes, primary sclerosing cholangitis…
Isolated form rarely progresses to systemic form, but systemic form may develop up to 1 year later • Liver and gallbladder rarely involved in vasculitides other than PAN Churg-Strauss syndrome Rheumatoid…
Occurs via portal vein, arterial system, or bile ducts Etiology/Pathogenesis • Bacterial pathogens most common in Western countries Klebsiella pneumoniae is now most common pathogen, followed by Escherichia coli Anaerobes are…
1% of all rhabdomyosarcomas occurring in children Most common malignant neoplasm of extrahepatic biliary tree in children • Occasionally seen in adults, usually in gallbladder • Long-term survival can be achieved with…
Most are sporadic • Seen in 50-100% of patients with familial adenomatous polyposis and Gardner syndrome Most common site of extracolonic polyps in syndromic patients • Signs and symptoms of biliary or…
Autosomal recessive inheritance 1 in 50,000 live births • Reactive hemophagocytic syndrome (secondary HLH) Infections, malignancies, autoimmune diseases • Hyperproduction of cytokines and chemokines due to T-cell dysregulation that causes “cytokine storm”…
> 90% of patients are female Most common in individuals of North European descent • Insidious onset with pruritus, fatigue, jaundice Often other associated autoimmune disorders • AMA(+) Minority of cases are…
Zoonotic infection caused by small, weakly gram-negative coccobacillus Most cases are attributed to B. henselae Clinical Issues • Most cases are children and young adults with history of cat exposure Usually…
