5-S-cysteinyldopa as diagnostic tumor marker for uveal malignant melanoma

Purpose: To evaluate the clinical significance of 5-S-cysteinyldopa (5-S-CD ), a major intermediate in melanin synthesis, as a potential diagnostic tum or marker for uveal malignant melanoma. Methods: The levels of 5-S-CD in the serum were measured by high-performanc e liquid chromatography in 16 patients with primary uveal melanoma, The lev els of 5-S-CD were also measured in both aqueous and vitreous humor in 10 p atients with uveal melanoma. The serum of healthy volunteers and patients w ith skin diseases other than melanoma, and the intraocular fluids of patien ts with cataract and vitreoretinal diseases were used as controls. Results: Serum concentrations of 5-S-CD in patients with uveal melanoma in the absence of extraocular metastases were close to those of controls, howe ver, serum concentrations of 5-S-CD were significantly elevated in patients with extraocular metastases of melanoma. Concentrations of 5-S-CD in the i ntraocular fluids. especially vitreous humor. were higher in patients with uveal melanoma than in controls. Conclusions: 5-S-CD in intraocular fluids may serve as a useful biochemical marker for the diagnosis of uveal melanoma. Serum 5-S-CD may contribute to the assessment of the presence and progression of extraocular metastases i n patients with uveal melanoma. Jpn J Ophthalmol 2001;45:538-542 (C) 2001 J apanese Ophthalmological Society.