review of literature on clinical pancreatology - The Pancreapedia

and other lymph nodes, salivary gland, biliary tract, prostate, and aortic wall. In 11 patientswho underwent PET before and after steroid therapy, FDG accumulation was diminished inalmost all systemic lesions, with a mean <strong>of</strong> maximum standardized uptake value (SUV max ) inthe pancreatic lesion from 5.1 to 2.7. Similar to the SUV level, serum IgG and IgG4 weredecreased in most <strong>of</strong> the cases after steroid therapy. It was concluded that FDG-PET is aneffective modality to evaluate the response <strong>of</strong> steroid therapy and the distribution and activity<strong>of</strong> various systemic lesions <strong>of</strong> autoimmune pancreatitis [316].MissdiagnosisAutoimmune pancreatitis (AIP) is a chronic inflammatory disease <strong>of</strong> the pancreas that isincreasingly encountered worldwide. It has generated considerable interest, in part becausethe inflammatory process usually responds dramatically to corticosteroid therapy. The mostcommon presentation mimics that <strong>of</strong> pancreatic cancer; thus, a correct diagnosis <strong>of</strong> AIP canavoid major surgery. However, the diagnosis is challenging, because its incidence is farlower than that <strong>of</strong> the diseases it mimics and there is no single diagnostic clinical feature ortest that can identify the full spectrum <strong>of</strong> AIP. Therefore, there has been increasinglyencountering patients misdiagnosed as having AIP. The misdiagnosis typically occurs inthree scenarios:- treatment <strong>of</strong> pancreatic or biliary malignancy with corticosteroids and/orimmunomodulators- treatment <strong>of</strong> chronic abdominal pain with corticosteroids and/or immunomodulators- performance <strong>of</strong> operative resection for autoimmune disease.This growing clinical problem must be reinforced by use <strong>of</strong> published guidelines for thediagnosis and management <strong>of</strong> autoimmune pancreatitis [317].Concomittant cancerAn asymptomatic 59-year-old man underwent pancreatoduodenectomy for a pancreaticmass that was discovered during a health check-up. Histopathology indicated typical features<strong>of</strong> CLPSP) or autoimmune pancreatitis along with the presence <strong>of</strong> abundant IgG4-positiveplasma cells throughout the mass. A small invasive ductal adenocarcinoma was observed inthe center <strong>of</strong> the area affected by LPSP [318].Case reportsIgG4-related sclerosing disease is a distinctive mass-forming lesion with frequent systemicinvolvement, most frequently the pancreas, salivary glands, and lacrimal glands. One reportdescribed a case manifesting with a previously unrecognized form <strong>of</strong> central nervous systeminvolvement. The 37-year-old man presented with signs and symptoms <strong>of</strong> spinal cordcompression at the thoracic level 9. Magnetic resonance imaging revealed an elongateddural mass extending from the fifth to tenth thoracic vertebra. Laminectomy and excision <strong>of</strong>the mass revealed dura expanded by a dense lymphoplasmacytic infiltrate accompanied bystromal fibrosis and phlebitis. IgG4+ plasma cells were increased and the proportion <strong>of</strong>IgG4+/IgG+ plasma cells was 85 percent. The patient also had a 1-year history <strong>of</strong> bilateralsubmandibular swelling due to chronic sialadenitis. Thus, IgG4-related sclerosingpachymeningitis represents a new member <strong>of</strong> the IgG4-related sclerosing disease familyaffecting the central nervous system. It seems that at least a proportion <strong>of</strong> cases described inthe <strong>literature</strong> as idiopathic hypertrophic pachymeningitis belong to this disease, especially as