[Double primary lung cancers producing alpha-fetoprotein]

A 81-year-old male with a high serum alpha-fetoprotein (AFP) level of 2644 ng/ml underwent left pneumonectomy for squamous cell carcinoma in the lower lobe and large cell carcinoma in the upper lobe. Both tumors were classified as pathological T2N0M0 and stage I. The AFP level was normalized to be 19 ng/ml in 49th postoperative day. Immunohistochemical staining using anti-AFP antibody demonstrated AFP granules only in the large cell carcinoma. The study of lectin affinity against the serum AFP revealed that the concanavalin A (Con-A) non-reactive fraction rate was 14%, the lentil agglutinin (LCA) non-reactive and strongly reactive subfractions were 16.7 and 83%, respectively and P2, P4 and P5 subfractions of the erythroaggultinating phytohemagglutinin (E-PHA) were 58.6, 24.9 and 16.5%, respectively. According to the analysis of 21 cases reported in the Japanese literature including our case, the AFP did not demonstrate a common affinity pattern against the Con-A but the common pattern resembling hepatocellular carcinoma against LCA and E-PHA.