[Case of spuriously high level of squamous cell carcinoma antigen in patient without carcinoma--HPLC and ultrafiltration are useful to analyze the true value].

: Squamous cell carcinoma antigen (SCCA) is a diagnostic tumor marker for the advanced uterine, cervix and lung tumor. Although SCCA is a prognostic indicator for some tumors, recent progress of this marker has shown that the SCCA could also be found in the serum of nonmalignant disease such as renal failure and others. Here, we report a case of spuriously high level of SCCA in patient without carcinoma, renal failure, head-and-neck disease and lung disease. An early fifties female who had been undergone the diagnostic conization for high-grade cervical intraepithelial neoplasia ten years ago and observed without special treatment with around 20ng/ml level of SCCA. She has no signs of tumor, renal failure, head-and-neck disease or lung disease until now. The high performance liquid chromatography with Superdex 200 showed the molecular weight of the major part of SCCA of the patient is more than 160 kDa and the part of 45 kDa, the same molecular weight as lung tumor, is trace amount. Moreover, the ultrafiltration analysis showed the SCCA of the present case did not penetrate the 100 kDa cut-filter, but SCCAs with other patients with uterine, cervix, lung tumor and renal failure did penetrate the filter. In this case, the analysis of molecular weight of SCCA using HPLC gel filtration and ultrafiltration is useful to rule out spuriously elevated SCCA.