Elevated AFP levels are seen in all of the following conditions, EXCEPT:

AFP concentration is increased only in patients with nonseminoma. The presence of an increased AFP level in a patient whose tumor shows only seminoma indicates that an occult nonseminomatous component exists, and the patient should be treated for nonseminomatous GCT. AFP is normally produced by the fetal yolk sac and also exists in multiple isoforms. It is elevated in GCT cells derived from the embryological yolk sac, including endodermal sinus tumor and embryonal carcinoma. It has also been found to be elevated in other neoplasms such as hepatocellular carcinoma, pancreatic, gastric, and lung cancer. Ref: Motzer R.J., Bosl G.J. (2012). Chapter 96. Testicular Cancer. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.