It has been postulated that analysis of alpha-fetoprotein (AFP) glycosylation heterogeneity in cancer patients whose AFP levels are elevated (e.g., non-seminomatous germ cell tumors, ovarian germ cell tumors and primary hepatocellular carcinoma) might provide useful clinical information. We undertook a study to determine whether scrutiny of AFP glycosylation heterogeneity in patients with non-seminomatous germ cell tumors would provide information useful in diagnosis, staging, prognosis, or monitoring for recurrence of disease following therapy. While an analysis of AFP glycosylation heterogeneity using Concanavalin A lectin chromatography did not provide useful information in regard to staging or prognosis, it does supply unique information useful in discriminating between benign liver dysfunction (e.g. alcoholic hepatitis, chemotherapy-related liver damage) and that due to nonsemininomatous germ cell tumors. It was also concluded that an analysis of Concanavalin A binding patterns is not sufficient to discriminate between recurrent non-seminomatous germ cell tumor and primary hepatocellular carcinoma in patients with elevated serum AFP.