Positive SMA means that the indicator SMA is expressed or abnormally elevated in the test sample, which has different meanings according to different tests. 1. Serologic examination: SMA refers to anti-smooth muscle antibody, and its positive expression can be seen in autoimmune diseases such as autoimmune hepatitis, lgG4-related hepatobiliary diseases and primary biliary cholangitis, etc. It has auxiliary significance in the diagnosis of autoimmune diseases, but it still needs to be combined with other tests to make a definite diagnosis. 2. Histopathological report: SMA is a commonly used immunohistochemical index, which refers to smooth muscle actin, used to mark smooth muscle cells, myoepithelial cells and myofibroblasts and tumors of their origins, and its positive expression indicates that the tissues originate from the above cells, but it can not be taken as the only diagnostic criterion for determining the benignity of the tumors, and needs to be combined with specific tissue samples and other tissue-specific tests. However, it cannot be used as the only diagnostic criterion to determine the benign or malignant nature of the tumor, and should be analyzed in conjunction with specific tissue samples and other tissue-specific markers. Tips: If you find SMA positive in any of the above two cases, you should consult a specialist for professional diagnosis and treatment advice.