Abstract
Peri-ampullary carcinoma refers to a group of neoplasms arising from the head of the pancreas, the distal common bile duct (CBD), and the duodenum. It is typically associated with metastases to intra-abdominal sites, distant lymph nodes, lungs, and bone. Metastasis of peri-ampullary carcinoma involving the brain is extremely rare, with less than five reported cases in current literature. We present a case of a 77-year-old male patient, who presented with a two-week history of diffuse abdominal pain and distension associated with post-prandial vomiting. A comprehensive workup involving diagnostic imaging revealed moderate ascites, dilated CBD, splenomegaly, and a heterogeneously enhancing periampullary lesion. Multiple heterogeneously enhancing lesions in the lungs with metastatic features were also seen. Whole body PET-CT showed a hypermetabolic minimally enhancing nodular lesion at the distal CBD. Other lesions with metastatic features were also noted, including multiple retroperitoneal nodes, multiple lung masses, and a hypermetabolic mediastinal node. Bronchoscopy was normal, however, a side-viewing endoscopy biopsy of the peri-ampullary mass confirmed a high-grade malignancy. After counselling the patient at length regarding available treatment options, sphincterectomy and CBD stenting were performed. However, the patient returned after two weeks with confusion, slurring of speech, and worsening abdominal distension. MR imaging demonstrated a heterogeneously enhancing mass in the left frontotemporal region, associated with a disproportionate amount of surrounding edema and mass effect with a significant midline shift. The patient was admitted to the intensive care unit, and the CBD stent was switched with an uncovered self-expandable metallic stent. Unwilling to undergo further treatment, the patient was discharged with scheduled close follow-ups. Though metastasis of peri-ampullary carcinoma to the brain is uncommon, this case highlights the importance of being cognizant of its clinical and radiological features to ensure prompt diagnosis and treatment.