title: Autoimmune pancreatitis mimicking Klatskin tumour on radiology.
abstract: Autoimmune pancreatitis (AIP) is categorised into two distinct types, AIP type 1 and 2. Although there can be multisystem involvement, rarely, the cholangitis associated with AIP can present radiologically in a manner similar to that of Klatskin tumour. We present the case of a 65-year-old man who was almost misdiagnosed with a Klatskin tumour because of the similarity in radiological features of the two aforementioned clinical entities. The patient presented with a history of jaundice, pruritus and abdominal pain, and work up showed deranged liver function tests, elevated cancer antigen 19-9 levels and positive antinuclear antibodies. CT scan of the abdomen showed findings suggestive of Klatskin tumour but due to diffuse enlargement of the pancreas and surrounding low-attenuation halo found on a closer review, a diagnosis of AIP was performed. The patient was started on standard corticosteroid therapy and responded well, with complete resolution of the radiological findings.
authors: Medical College, Aga Khan University, Karachi, Pakistan.
authors: Yousaf Bashir
authors: YB
authors: Hadi
authors: Aga Khan University, Karachi, Pakistan.
authors: Abdul Malik Amir Humza
authors: AM
authors: Sohail
authors: Department of Radiology, The Aga Khan University, Karachi, Pakistan.
authors: Zishan
authors: Z
authors: Haider
mesh_terms: D015746:Abdominal Pain / Q000175:diagnosis; D000368:Aged; D000974:Antibodies, Antinuclear / Q000276:immunology; D001327:Autoimmune Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000276:immunology / Q000473:pathology; D003937:Diagnosis, Differential; D006801:Humans; D007565:Jaundice / Q000175:diagnosis; D018285:Klatskin Tumor / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D010195:Pancreatitis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000276:immunology / Q000473:pathology; D014057:Tomography, X-Ray Computed
chemical_list: D000974:Antibodies, Antinuclear