Dilemmas and limitations interpreting carbohydrate antigen 19-9 elevation after curative pancreatic surgery: A case report.

Abstract

Serum carbohydrate antigen 19-9 (CA19-9) is routinely used in the management of pancreatic cancer for diagnosis, prognostication and surveillance purposes despite its low specificity. This case report demonstrates the challenges of interpreting elevated serum CA19.9 levels in a patient with pancreatic cancer. We performed a Whipple's procedure in an otherwise fit 78-year-old man for pancreatic adenocarcinoma. One year after surgery, he presented with a non-malignant anastomotic stricture that was associated with an elevated serum CA19-9. Subsequently, he presented with biliary sepsis secondary to an infected liver cyst. CA19-9 in the cyst fluid and serum were elevated. On both of these occasions, serum CA19-9 normalised without any clinical or radiological evidence of recurrence. Despite sound clinical acumen and investigations, it may be hard to differentiate cancer recurrence from benign aetiologies. Benign conditions may cause elevation of CA19-9, even in the setting of previous malignancy. Persistently high CA19-9 level post-decompression raises suspicion of malignancy. This case serves as a reminder for clinicians that non-specific increases in CA19-9 after curative surgery is not uncommon. We recommend careful interpretation of CA19-9 levels in combination with clinical history, physical examination and radiological investigations.