A Case of Enteritis Cystica Profunda in the Ampulla of Vater Mimicking Choledochocele
The patient, a 58-year-old woman, visited the hospital for health examination without any particular symptom, and esophagogastroduodenoscopy (EGD) showed about 1 cm-sized smooth protruding lesion on the ampulla of Vater of the duodenum (). She had received surgical resection for uterine myoma 10 years before. There was no noteworthy fact in her family history and social history. On her visit, vital signs were measured as blood pressure 120/80 mm Hg, pulse rate 70/min, respiration rate 18/min, and body temperature 36.5℃. She had clear consciousness and healthy appearance. At physical examination, anemic conjunctiva, icteric sclera, cervical lymph nodes were not noted. Chest auscultation did not show any abnormality, and heart sound was normal. There was no tenderness, palpable mass and bowel sound was normal. There was no particular finding in limb and neurological examination. In peripheral blood test, white blood cell was 6,900/mm3, hemoglobin 13.9 g/dL, and platelet count 233,000/mm3. The results of blood chemistry were aspartate aminotransferase/alanine aminotransferase 21/27 IU/L, alkaline phosphatase 61 IU/L, total protein 6.7 g/dL, albumin 4.3 g/dL, total bilirubin 0.7 mg/dL, amylase 39 U/L, lipase 241 U/L, blood urea nitrogen 16.0 mg/dL, and creatinine 0.8 mg/dL. The results of immunoassay test were hepatitis B surface antigen negative, hepatitis B surface antibody positive, and hepatitis C virus antibody negative, and serum tumor markers were alpha fetoprotein 1.7 ng/mL, carcinoembryonic antigen 0.9 ng/mL, and carbohydrate antigen 19-9 2.30 U/mL. In duodenosocpy, about 1 cm-sized softly protruding submucosal tumor covered with normal mucosa was observed in the proximal part of the major papilla of the ampulla of Vater. The tumor sank softly and then elevated again when pressed with biopsy forceps, and the major papilla was normal (). As choledochocele was suspected, we performed magnetic resonance cholangiopancreatography (MRCP) but the dilation of the common bile duct surrounding the papilla or a cystic lesion connected to the common bile duct was not observed. In the results of endoscopic retrograde cholangiopancreatography (ERCP), when contrast agent was injected, the dilation of the papillary part or a cystic lesion connected to the common bile duct was not observed, and anomalous pancreaticobiliary ductal union or dilation was not observed either (). Thus, with excluding the possibility of choledochocele, we suspected submucosal tumor and performed endoscopic ultrasonography (EUS). In the results, about 8 mm sized anechoic lesion having multiple septa was observed in the submucosal layer (). For pathologic confirmation, the subepithelial lesion was resected by snare polypectomy with papillary orifice being preserved under the side viewing endoscopy (). In histopathologic examination, a number of cysts lined with mucous columnar epithelia were observed in the submucosal layer, and because dimorphism of cystic epithelial cells was not observed, the case was diagnosed as ECP (). As the patient was healthy and there was no other abnormal finding on abdominal magnetic resonance imaging and EGD, the patient was discharged without any further evaluation and has been followed up without any notable symptom for 1 year.