INTRODUCTION: Primary duodenal cancers are a rare occurrence among gastrointestinal malignancies. Cancers that occur within the duodenum include adenocarcinoma, neuroendocrine, lymphomas and leiomyosarcomas. Diagnosis is often delayed leading to worsening disease burden and poorer outcomes. We present an unusual case of a female with a history of triple negative invasive ductal carcinoma who was unfortunately found to have a primary adenocarcinoma of the duodenum. CASE DESCRIPTION/METHODS: The patient is a 61 year old female with a history of triple negative invasive ductal carcinoma status post mastectomy, radiation and chemotherapy who presented to her outpatient oncologist. Six years following her completed treatment, the patient developed symptoms of dyspepsia and iron deficiency anemia. She underwent CT imaging of the abdomen demonstrating duodenal obstruction and evidence of intrathoracic metastasis. The patient subsequently underwent push enteroscopy which revealed a duodenal mass. Duodenal stents were subsequently placed and biopsies taken intraoperatively. A PET scan was then performed and demonstrated hypermetabolic activity at the third and fourth portion of the duodenum with additional lung nodules consistent with metastasis. The biopsies resulted as a primary adenocarcinoma of the duodenum. The patient was started on oxaliplatin chemotherapy. Three months later a follow up PET scan was performed revealing interval improvement of the primary duodenal tumor and lung nodules. The patient continues to undergo palliative chemotherapy and has been consistently following up for her office visits. DISCUSSION: Primary duodenal cancer is a rare disease which reflects approximately 0.3–0.5% of all gastrointestinal malignancies. Adenocarcinoma commonly arises in the third and fourth portions of the duodenum. Most common presenting signs and symptoms include epigastric pain, anemia and weight loss. Since presenting symptoms are vague in nature, early diagnosis is often missed. One study found that at time of diagnosis, less than 40% could pursue curative resection. Tumor resectability and presence of metastasis have been regarded as the strongest factors influencing patient outcomes. One retrospective study demonstrated that patients who underwent tumor resection had a significantly longer survival rate compared to those who had no surgery. At the time of diagnosis, our patient demonstrated metastatic disease and therefore underwent palliative duodenal stenting and chemotherapy with oxaliplatin.