Urine melanin is a test to determine the abnormal presence of
melanin in the urine. Thormahlen's test; Melanin - urine How the
Test is Performed A clean-catch urine sample is needed. How to
Prepare for the Test No special preparation is needed. How the
Test Will Feel The test involves only normal urination. Why the
Test is Performed This test is used to diagnose melanoma, a type
of skin cancer that produces melanin. If the cancer spreads
(especially within the liver), the cancer may produce enough of
this substance that it shows up in the urine. Normally, melanin
is not present in urine. Normal value ranges may vary slightly
among different laboratories. Some labs use different
measurements or test different samples. Talk to your doctor
about the meaning of your specific test results. What Abnormal
Results Mean If melanin is present in the urine, malignant
melanoma is suspected. There are no risks associated with this
test. This test is rarely done to diagnose melanoma becausethere
are better tests available.