A duodenal gastrointestinal stromal tumor mimicking a pancreatic neuroendocrine tumor: a case report.

BACKGROUND: Duodenal gastrointestinal stromal tumors are rare. If tumor growth is extraluminal and involves the head of the pancreas, the diagnosis of a duodenal gastrointestinal stromal tumor is difficult. CASE PRESENTATION: A 44-year-old Japanese woman was referred to our hospital with anemia. An enhanced computed tomography scan showed a hypervascular mass 30 mm in diameter, but the origin of the tumor, either the duodenum or the head of the pancreas, was unclear. Upper gastrointestinal endoscopy revealed bulging accompanied by erosion and redness in part of the duodenal bulb. Mucosal biopsy was not diagnostic. Endoscopic ultrasound fine-needle aspiration was difficult to perform because a pulsating blood vessel was present in the region to be punctured. These findings led to a diagnosis of pancreatic neuroendocrine tumor invasion to the duodenum. The patient underwent pancreaticoduodenectomy. Histologically, the tumor was made up of spindle-shaped cells immunohistochemically positive for c-Kit and CD34. The tumor was ultimately diagnosed as a duodenal gastrointestinal stromal tumor. CONCLUSION: Extraluminal duodenal gastrointestinal stromal tumors are rare and mimic pancreatic neuroendocrine tumors. Endoscopic ultrasound fine-needle aspiration is useful for preoperative diagnosis, but it is not possible in some cases. Intraoperative diagnosis based on a completely resected specimen of the tumor may be useful for modifying the surgical technique.

A Case of Stage II Ascending Colon Cancer with Cardiac Tamponade Due to Pericardial Metastasis.

BACKGROUND Malignant tumors, such as lung and breast cancers, can metastasize to the heart. However, cardiac metastasis rarely occurs in colorectal cancer. Cardiac metastasis cases are typically asymptomatic and rarely cause cardiac tamponade. Heart failure due to systemic metastasis is a terminal symptom; therefore, cardiac metastasis is rarely diagnosed when a patient is alive. We report a case of stage II ascending colon cancer with cardiac tamponade due to pericardial metastasis. CASE REPORT The patient was a 63-year-old woman who underwent laparoscopic ileocecal resection for ascending colon cancer. The final pathological diagnosis was stage IIB cancer. At the time of surgery, computed tomography scans revealed no metastases to the regional lymph nodes, liver, lungs, and other organs. The patient was then referred for dyspnea 5 months after the surgery. Computed tomography revealed large quantities of pericardial effusion, and the patient was diagnosed with cardiac tamponade. The symptoms were alleviated after pericardiocentesis. Cytological examination of the pericardial fluid confirmed the diagnosis of adenocarcinoma, and by extension, cardiac metastasis of the ascending colon cancer. Anticancer agents were recommended, but the patient opted for palliative treatment. CONCLUSIONS We report a rare case of ascending colon cancer with pericardial metastasis. The advancements in chemotherapy have made the prognosis of colorectal cancer more favorable. The prevalence of pericardial metastasis is expected to increase as well. As such, it is necessary to discuss similar case encounters and establish appropriate treatment.

A liver metastasis 7 years after resection of a low-risk duodenal gastrointestinal stromal tumor.

Duodenal gastrointestinal stromal tumors (dGISTs) are rare, and a lack of consensus exists regarding their treatment, particularly for recurrent disease. We herein report a rare case of liver metastasis 7 years after resection of a low-risk duodenal gastrointestinal stromal tumor. A 45-year-old woman revealed positive fecal occult blood. Upper gastrointestinal endoscopy revealed a submucosal duodenal tumor with ulceration and oozing on the apex. Endoscopic ultrasound showed a hypoechoic mass originating in the submucosa. Contrast-enhanced abdominal computed tomography (CT) revealed a 30-mm hyper-vascular tumor in the duodenal bulb. The patient underwent partial resection of the duodenal bulb with distal gastrectomy, followed by Roux-en-Y reconstruction. Histopathological evaluation revealed a tumor comprised of spindle-shaped cells including 5 mitotic figures per 50 high-power fields. Immunohistochemical evaluation indicated that the tumor cells were positive for c-Kit and CD34 expression. The tumor was diagnosed as low-risk dGIST. Postoperative follow-up was continued, and 7 years later, CT revealed a 39-mm enhanced tumor in liver segment 4. The tumor was diagnosed as a metastatic liver tumor, and the patient underwent S4 partial hepatectomy. As a result of histological and immunohistochemical analysis, the tumor was diagnosed as a liver metastasis from dGIST. The patient has been receiving oral imatinib 400 mg daily and remains free of disease 5 years after her last surgery. Low-risk dGIST can metastasize relatively long after surgery. However, an excellent long-term prognosis may be achieved by combining complete resection and imatinib therapy in patients with recurrent liver metastases.