Elevation of CA 19-9 in Mirizzi Syndrome in the Absence of Malignancy: A Case Report

BACKGROUND Mirizzi syndrome (MS) is relatively a rare condition; incidence rates may increment with age. It is characterized as an obstruction of the common hepatic duct (CHD) auxiliary to outward compression of an infected stone in the cystic duct. Carbohydrate antigen (CA) 19-9 is a tumor marker that is usually related to upper-gastrointestinal malignancies. However, a few case reports have shown high levels of CA19-9 in the absence of malignancy. In this case, we report a case of a patient with MS, elevated CA19-9, and radiological findings suggesting gallbladder cancer, which shows the challenges of diagnosis and therapeutic procedures. CASE REPORT We report the case of a 71-year-old Saudi man who presented to the emergency department with signs of obstructive jaundice. Magnetic resonance cholangiopancreatography (MRCP) revealed cholelithiasis, with a huge cystic duct stone compressing the CHD, resulting in mild intra-/extrahepatic biliary dilatation and positive MRCP pearl necklace sign for adenomyomatosis of the gallbladder. Serum tumor markers revealed raised levels of CA19-9 to 21 068 u/ml. The patient underwent laparoscopic cholecystectomy. Biopsy results confirmed the diagnosis of acute calcular cholecystitis and adenomyosis with no malignancy. CONCLUSIONS We report what can be considered a rare case of Mirizzi syndrome with a very high CA19-9 marker, in an elderly patient, in the absence of malignancy. This illustrates that Mirizzi syndrome and cholangiocarcinoma are difficult to distinguish, and the diagnosis is considered challenging. Thus, a high index of suspension must be kept in mind, especially in elderly patients, to rule out the cause of malignancy and thus to create an appropriate management plan.