Abstracts: CLINICAL VIGNETTES/CASE REPORTS - COLON
Remote Recurrence of Colonic Adenocarcinoma Presenting as an Isolated Mass in the Pancreatic Head: A Case Study
Pancreatic masses are usually primary tumors with metastasis representing only 1.8-7.6%. Colorectal cancer (CC) is the third most common cause of cancer death in the United States. The five year survival and recurrence rates are dependent upon the staging at the time of diagnosis but the incidence of recurrent CC is reported at 20-30% with 80% of recurrence occurring within the first two years of diagnosis and treatment. At the time of diagnosis, 20% of patients have distant metastasis, most commonly to regional lymph nodes, liver, lungs, and peritoneum. Metastasis of colonic adenocarcinoma (CA) to the pancreas is relatively rare and metastasis presenting 5 years from prior treatment is far more uncommon. We present a case of metastatic CA to the pancreas 5 years after initial diagnosis.
An 80-year-old white female with a history of presumed stage II CA status post right-hemicolectomy five years ago, presented with cramping of the left lower quadrant. The patient reported 50 lb. weight loss over the prior three months but denied change in bowel habits. Computed tomography demonstrated uncomplicated left sided diverticulitis and a 3.2 x 2.9 cm soft tissue mass in the pancreatic head. Serum CEA was markedly elevated at 99.1 ng/mL with CA19-9 mildly elevated at 236 unit/mL. Endoscopic ultrasound revealed an irregular, hypoechoic mass measuring 30 x 30 mm in the pancreatic head and neck with poorly defined borders. There was evidence of invasion into the superior mesenteric vein and artery. Fine needle aspiration was positive for adenocarcinoma with immunohistochemical staining positive for CK20 and CDX diffusely and negative for CK7, chromogranin, and synaptophysin in a pattern consistent with CA of metastatic origin rather than primary pancreatic adenocarcinoma. Palliative chemotherapy was initiated but the patient opted to pursue hospice care after one cycle.
Despite the fact that the identification of pancreatic lesions has become more feasible with the advent of EUS, the management of such lesions, particularly when metastatic in nature, remains unchanged. Depending on size and location, some metastatic lesions of CC can be surgically resected if detected early. In general, most professional societies differ with regards to post-treatment CC surveillance but all are in agreement that the minimum window should be five years. Although rare, metastasis should be suspected in any patient with a history of CC and newly detected pancreatic mass.© The American College of Gastroenterology 2015. All Rights Reserved.