Extremely elevated alpha-fetoprotein due to acute exacerbation of chronic hepatitis B without malignancy: a case report

Alpha-fetoprotein is produced by a variety of tumors such as hepatocellular carcinoma, hepatoblastoma, and germ cell tumors of the ovary and testes. However, we present a case of significantly elevated serum alpha-fetoprotein without evidence of malignant disease in a patient who is a carrier of chronic hepatitis B. A 60-year-old Korean man presented with markedly increased alpha-fetoprotein (2350 ng/mL; normal 7 × 105 IU/mL). Our patient was diagnosed with acute exacerbation of chronic hepatitis B, and we presumed that this condition might be related to extremely elevated alpha-fetoprotein. When our patient was treated with entecavir, the serum alpha-fetoprotein level immediately decreased, in parallel with the hepatitis B virus deoxyribonucleic acid copy number. We report a rare case of extremely elevated alpha-fetoprotein due to acute exacerbation of chronic hepatitis B without any malignancy, and a decrease in this tumor marker simultaneous with a decrease in hepatitis B virus deoxyribonucleic acid copy number on entecavir treatment. This case report is important due to the rarity of the case; furthermore, it provides details of a diagnostic process for a variety of benign diseases and malignant tumors that should be considered in patients with elevated alpha-fetoprotein. Thus, we present a case report, along with a review, that will be helpful for diagnosis and treatment of patients with elevated alpha-fetoprotein.