Pancreatic metastasis from rectal adenocarcinoma: A case report

Pancreatic metastasis from colorectal cancer is exceptionally rare, yet accurate diagnosis and management are pivotal. We describe a 66-year-old female patient with a history of low rectal adenocarcinoma treated 13 years earlier, who during routine surveillance presented with elevated carcinoembryonic antigen (CEA) levels and was found to have a solitary hypodense lesion in the tail of the pancreas on computed tomography. Biopsy revealed moderately differentiated adenocarcinoma and immunohistochemistry confirmed colorectal origin. After multidisciplinary review, the patient underwent distal pancreatectomy with splenectomy and en bloc resection of adjacent adrenal and renal tissue; histology confirmed metastatic colorectal adenocarcinoma with clear margins, no lymphatic invasion. She subsequently received six months of adjuvant XELOX chemotherapy and as of last follow-up remains free of recurrence. This case underscores the need to consider metastasis from colorectal primary when evaluating pancreatic lesions in patients with prior colorectal malignancy, and illustrates the essential role of immunohistochemical staining in differentiation from primary pancreatic cancer. Surgical resection in isolated disease, combined with adjuvant therapy, may offer favourable outcomes.