1285 Elevated CEA and CA 19-9 Producing Carcinoma: Think Beyond the Digestive System!

Abstract

INTRODUCTION: Carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9) are validated and well-known tumor markers for colorectal and pancreatic malignancies but data concerning these markers in bladder carcinoma are limited. We report a rare case of bladder carcinoma with metastasis to the bone marrow producing very high serum levels of CEA and CA 19-9. CASE DESCRIPTION/METHODS: A 68-year-old man with a medical history of hypertension, COPD presented with altered mental status. The patient further reported anorexia, unintentional weight loss of 50 lbs and intermittent hematuria over the last few months. He was confused but hemodynamically stable on presentation. Initial laboratory data showed pancytopenia, ALP of 712 U/L with normal transaminases and bilirubin, urine microscopy showed >100 red blood cells/HPF. A CT scan of the abdomen showed bilateral hydronephrosis with thickening of the urinary bladder and diffusely abnormal bone marrow. Bone marrow biopsy showed poorly differentiated metastatic carcinoma with positive immunohistochemical (IHC) stains for cytokeratin (CK)7 and CK20. In addition, very high levels of tumor markers CA19-9 42,635 U/ml, CEA 347 ng/ml raised a possibility of origin from the gastrointestinal or pancreatobiliary system. Subsequently, upper endoscopy, colonoscopy, EUS, and magnetic resonance cholangiopancreatography (MRCP) were performed and results were unremarkable. Finally, a cystoscopy was performed showing multiple papillary tumors throughout the bladder. Unfortunately, the patient died before any further workup and therapeutic interventions were initiated. DISCUSSION: Elevated levels of CEA and CA19-9 have been demonstrated in TCC of the bladder. The specificity of CEA for diagnosis of colorectal cancer is 89 percent while the specificity of CA 19-9 for pancreatic cancer goes up to 85% at a serum level >37 U/ml but neither are useful tools in the primary diagnosis of TCC. The pattern of staining with the CK20 and CK7 may be helpful in narrowing the diagnostic spectrum, but both can show positivity in pancreatobiliary and urothelial cancers. IHC allows limited determination of the tissue of origin in poorly differentiated carcinomas due to atypical staining patterns. In conclusion, when CEA and CA19-9 serum levels are elevated, a gastrointestinal malignancy should be excluded and one should be mindful of the existence of CEA and CA19-9 producing TCC and thus examine the urologic tract.