LAUSR

Abstract A 69-year-old woman visited our outpatient clinic due to abdominal pain and anorexia. She received initial diagnostic workup, and was admitted to the hospital as an inpatient because of ileus. CT showed tumor with a diameter of 3cm in upper left abdomen, liver metastasis, peritoneal fluid localized in the pelvic cavity, and peritoneal node. Upper and lower gastrointestinal endoscopy showed no abnormalities, and percutaneous liver biopsy confirmed adenocarcinoma. PET showed a focal abnormal uptake in proximal jejunum, but no abnormalities in pancreas and biliary tract. We diagnosed the patient with small bowel cancer. It was considered unresectable, and FOLFOX chemotherapy was initiated. However, during FOLFOX chemotherapy after 1st course, CT showed that exacerbation of primary lesion and liver mass, and significant increase in ascites. She subsequently died of pneumonia day 32 after the start of chemotherapy. Autopsy findings revealed primary small bowel adenocarcinoma with proximal jejunum. Histological response was Grade1a. The incidence of small bowel adenocarcinoma (SBA) is very low, accounting for 0.1%-0.3% of all gastrointestinal malignant neoplasms. Many cases have been reported to be within 50 cm of Treitz ligament or Bauhin valve. For diagnosis of SBA, some reports suggest small bowel series, gastrointestinal endoscope, CT, and PET are useful. However, in many advanced cases it is difficult to apply curative therapy at the time of discovery. There is no standard treatment especially for unresectable small bowel cancer, and the prognosis is poor. In this case SBA was confirmed by metastatic lesion biopsy and exclusion diagnosis. Because the disease was already advanced at the time of diagnosis and furthermore time was necessary for diagnostic workup, it caused deterioration of the general condition. As a result, adequate chemotherapy could not be performed. There is a need for further case studies to establish diagnosis and treatment of SBA.