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Identification and characterization of melanin in choroidal melanoma by electron paramagnetic resonance spectroscopy (EPR)
Author(s) -
ROMANOWSKA DIXON B,
KLONOWSKA A,
PLONKA P,
SARNA T
Publication year - 2014
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2014.4247.x
Subject(s) - melanin , phototype , melanoma , electron paramagnetic resonance spectroscopy , choroidal melanoma , enucleation , electron paramagnetic resonance , ocular melanoma , medicine , pathology , dermatology , chemistry , nuclear magnetic resonance , ophthalmology , cancer research , biochemistry , physics , surgery
Purpose The purpose of this study was to determine the quantity and type of melanin in choroidal melanomas in correlation with patient’s clinical characteristics. Methods Melanoma‐containing samples were obtained after enucleation surgery, performed because advanced choroidal melanoma was diagnosed, not qualified to preserving eye therapy. Frozen samples were examined at liquid nitrogen temperature by EPR spectroscopy. Results Examination showed that choroidal melanoma cells had a low eumelanin to pheomelanin index. In most of investigated melanoma‐containing samples the presence of pheomelanin was determined. Also strict correlation between patient’s clinical characteristics such as skin phototype, iris and hair color and melanin type in tumor were observed. No correlation however were found between histopathological type and quality and quantity of melanin in choroidal melanoma. Macroscopic analysing cases of choroidal melanoma were characterized by wide pigment variations. The presence of tide correlation between tumor color and type of melanin was observed. Conclusion Pheomelanin fenotype occurred in tumors with low content of pigment. Tumors intensively pigmented (black, dark brown) belong to eumelanin tumors.