Abstract
The case was a 59-year-old male who presented with jaundice and was hospitalized for evaluation and treatment. Blood examinations revealed a slightly elevated carcinoembryonic antigen (CEA) level and CA19-9 level of 9.3 ng/ml and 75.2 U/ml, respectively. Abdominal computed tomography (CT) and magnetic resonance imaging (MRI) examinations revealed a tumor with a maximum diameter of 6 cm in the horizontal lesion of the duodenum.
Endoscopic examinations of the upper gastrointestinal tract using a lateral vision mirror revealed ulceration, and in a biopsy of the same region, the patient was diagnosed with a gastrointestinal stromal tumor (GIST) of the duodenum. Based on this diagnosis, a pancreaticoduodenectomy was performed. In histopathological examinations, the findings were positive for c-kit and CD34, the mitotic count was 10 / 50HPF, and the patient was diagnosed with high-risk GIST. After obtaining sufficient informed consent, we performed postoperative adjuvant chemotherapy using 400 mg/day of imatinib. After surgery, the tumor markers became negative, and at 36 months after surgery, no recurrence has yet been observed. Cases of GIST in which the tumor markers exhibit high values are rare and past reports indicate that the degree of malignancy may be high, and we herein report the findings of this case, including the results of immunostaining together with some bibliographic considerations.
