Rodriguez Eduardo A, Williams Frederick K
Department of Internal Medicine, University of Miami Palm Beach Regional Campus, Atlantis, FL, USA.
Am J Case Rep. 2015 May 22;16:305-9. doi: 10.12659/AJCR.893300.
Autoimmune pancreatitis is an IgG4-related fibroinflammatory condition often associated with obstructive jaundice, as most lesions are located at the head of the pancreas. IgG4 level can help in the diagnosis, but it is normal in nearly 30% of affected patients.
A 55-year-old woman presented with a 5-month history of 20-pound unintentional weight loss and intermittent abdominal pain. She had an unremarkable abdominal exam and significant findings included a small, non-mobile rubbery left axillary lymph node. Complete blood count, complete metabolic panel, amylase, anti-smooth muscle antibody, antimitochondrial antibody, carcinoembryonic antigen, Ca 19-9, complement C3 and C4, antinuclear antibody, anti-Smith double-strand antibody, and IgG4 were all within normal limits. CT of the abdomen showed a mass in the junction of the body and tail of the pancreas and endoscopic ultrasound showed it as encasing the splenic artery. Fine-needle aspiration cytology demonstrated follicular hyperplasia, obliterative phlebitis, storiform fibrosis, and negative staining for IgG4 and malignancy. Left axillary lymph node biopsy demonstrated follicular hyperplasia. PET scan revealed hypermetabolic uptake of the pancreas tail, bone marrow, and spleen, as well as diffuse lymphadenopathy. Bone marrow biopsy showed follicular hyperplasia and was negative for malignancy. The patient was started on 40 mg of oral prednisone for possible autoimmune disease. During follow-up, she reported progressive improvement and a repeat PET scan 6 months later showed marked improvement.
A normal IgG4 value should not decrease the clinical suspicion of IgG4-related disease. If clinical, histological, and radiological findings coincide, glucocorticoids should be initiated with subsequent follow-up to evaluate for a response.
自身免疫性胰腺炎是一种IgG4相关性纤维炎症性疾病，常伴有梗阻性黄疸，因为大多数病变位于胰头。IgG4水平有助于诊断，但近30%的受累患者其水平正常。
一名55岁女性，有5个月20磅非故意体重减轻及间歇性腹痛病史。她的腹部检查无异常，重要发现包括左侧腋窝一个小的、活动度差的橡皮样淋巴结。血常规、全代谢组、淀粉酶、抗平滑肌抗体、抗线粒体抗体、癌胚抗原、Ca 19-9、补体C3和C4、抗核抗体、抗史密斯双链抗体及IgG4均在正常范围内。腹部CT显示胰腺体尾部交界处有一肿块，内镜超声显示其包绕脾动脉。细针穿刺细胞学检查显示滤泡增生、闭塞性静脉炎、席纹状纤维化，IgG4及恶性肿瘤染色阴性。左侧腋窝淋巴结活检显示滤泡增生。PET扫描显示胰腺尾部、骨髓和脾脏代谢增高摄取，以及弥漫性淋巴结病。骨髓活检显示滤泡增生，恶性肿瘤阴性。该患者因可能的自身免疫性疾病开始口服40mg泼尼松。随访期间，她报告病情逐渐改善，6个月后重复PET扫描显示明显改善。
IgG4值正常不应降低对IgG4相关疾病的临床怀疑。如果临床、组织学和影像学表现相符，应开始使用糖皮质激素，随后进行随访以评估反应。
