Methimazole (MMI)-induced acute pancreatitis is very rare but severe adverse reaction. A 51-yr-old male developed a high fever, chills, and abdominal pain, two weeks after commencement on MMI for the treatment of Graves' disease. There was no evidence of agranulocytosis, and fever subsided soon after stopping MMI treatment. However, 5 hr after taking an additional dose of MMI, abdominal pain and fever developed again. His symptoms, biochemical, and imaging studies were compatible with acute pancreatitis. After withdrawal of MMI, he showed clinical improvement. This is the first case of MMI-induced acute pancreatitis in Korea. Clinicians should be aware of the rare but possible MMI-induced pancreatitis in patients complaining of fever and abdominal pain.Graphical Abstract

Background/Aims: Peritoneal carcinomatosis with malignant ascites is common in patients with advanced gastric cancer (GC). The detection of tumor cells is the gold standard for the diagnosis of malignant ascites; however, it often requires complementary tests because of its low sensitivity. Herein, we measured the levels of tumor markers in the malignant ascites of GC patients (GC-ascites) and benign ascites of liver cirrhosis patients (LC-ascites) to elucidate the diagnostic value of tumor markers in GC-ascites. Materials and Methods:The levels of CEA, cancer antigen 72-4 (CA 72-4), CA 19-9, and CA 125 were measured in 138 GC-ascites and 64 LC-ascites samples obtained from the National Biobank of Korea. We performed receiver operating characteristic curve analysis to determine the optimal cutoff value for each tumor marker. Results: CEA, CA 72-4, and CA 19-9 levels were significantly higher in GC-ascites than in LC-ascites. There was no difference in tumor marker levels between GC-ascites samples irrespective of cytology. CEA, CA 72-4, and CA 19-9 had sensitivities of 85.5%, 79.0%, and 61.6%, respectively, and specificities of 96.8%, 100.0%, and 89.1%, respectively, for distinguishing GC-ascites samples from LC-ascites samples. The diagnostic accuracy was improved by combining two or more tumor markers. The combination of CEA and CA 72-4 showed the highest sensitivity (86.2%) and specificity (100%). Conclusions: Measurement of tumor markers, such as CEA, CA 72-4, and CA 19-9, in ascites samples could help diagnose GC-ascites, and combining two or more tumor markers could further increase the diagnostic yield, even in cytology-negative patients.