Gastrointestinal: Multiple metastases of laterally spreading non-ampullary duodenal adenocarcinoma with gastric phenotype.

Abstract

Non-ampullary duodenal adenocarcinoma could be divided into two major types: gastric and intestinal types with mucin immunohistochemistry. Ushiku et al. reported that the gastric type has a worse prognosis than the intestinal type in patients with duodenal adenocarcinoma. However, few studies have examined the malignant potential of gastric-type duodenal adenocarcinomas. A 76-year-old woman with respiratory symptoms underwent computed tomography, which showed bilateral cavitary pulmonary lesions. Esophagogastroduodenoscopy detected a duodenal tumor spreading from the superior duodenal angle to the prepylorus (Fig. 1a–c). Biopsy showed well-differentiated adenocarcinoma, which was immunohistochemically positive for the MUC5AC (gastric foveolar mucin) and focally positive for the MUC6 (pyloric and Brunner's gland mucin), but negative for MUC2 (major intestinal goblet cell mucin), CDX2 (intestinal transcription factor), and CD10 (intestinal epithelial cells) (Fig. 2a–g). The tumor was soft and flat without any findings suggesting muscle invasion. But positron emission tomography/computed tomography revealed increased uptake in the duodenal bulb, multiple lung lesions, para-aortic lymph nodes, sternum, and ninth thoracic spine (Fig. 1d–f). Histology and immunohistochemistry of lung lesion showed mucinous adenocarcinoma with gastric-type mucin expression, which was similar to the finding of duodenal carcinoma (Fig. 2h–n). Therefore, we diagnosed the patient with multiple metastases from gastric-type duodenal adenocarcinoma. The patient underwent palliative chemotherapy with S-1 plus oxaliplatin, but she died from progressive disease 7 months after diagnosis.