The only absolute way to make a cancer diagnosis is to remove a small sample of the tumor
and look at it under the microscope in a procedure called a biopsy
After a diagnosis is made, doctors analyze the tissue samples and test results to find out how far the cancer has spread and to determine the stage of the cancer. The stage lets oncologists know which choices will be available for treatment and it informs prognoses.
helps to find whether it is metastatic or not.
I recommend you should go for second opinion
to confirm the disease with biopsy. Whether it is metastatic or not is next step.