Can an advanced melanoma that has spread in all the body have signs in normal blood test?

Yes: Lactate dehydrogenase (ldh) can be elevated in metastatic melanoma. When it is, it is a poor prognostic sign. Another, less proven, test is called tumor antigen 90 (ta-90). It is thought by some to be elevated in advanced melanoma. I have found it to be nonspecific and no longer use it in my practice, however.

Possibly: It is possible. Usually, there might be anemia, abnormal liver test, or an increased ldh. Radiology tests and biopsies are more reliable than blood test in this disease.

Yes: Yes it is possible. Unfortunately there are not reliable blood tests for metastatic melanoma, .