ObjectiveTo study the infiltration situation of breast cancer surface skin, and explore the characteristics of infiltration of breast cancer surface skin at the molecular level. MethodsNested reverse transcription-polymerase chain reaction technique was used to detect the expressions of human mammaglobin(hMAM)mRNA in 15 cases of hyperplasia of mammary gland tissues, 15 cases of breast fibroadenoma tissues, and 60 cases of breast cancer tissues and their corresponding tumor surface skins. The relationship of the hMAM mRNA expression in the surface skins of breast cancer tissue to its clinicopathologic characteristics was analyzed. ResultsThe hMAM mRNA positive expressions in the breast fibroadenoma tissues, hyperplasia of mammary gland tissues, and breast cancer tissues were 40.00%(6/15), 53.33%(8/15), and 83.33%(50/60), respectively, which in the breast cancer tissues was significantly higher than that in the breast fibroadenoma tissues or hyperplasia of mammary gland tissues(P < 0.05). There was no hMAM mRNA positive expression in the surface skin of fibroadenoma or hyperplasia of mammary gland tissues, but there was 3(5.00%)cases of the hMAM mRNA positive expressions in the breast cancer surface skin. The hMAM mRNA positive expression in the breast cancer surface skin was not related with the patient age, tumor diameter, and tumor staging(P > 0.05), but was related with axillary lymph nodes metastasis and distance from tumor to nipple less than 4 cm(P < 0.05). ConclusionsThe hMAM mRNA highly expresses in breast cancer tissue and it has a certain value in the diagnosis of infiltration of breast cancer surface skin. The patients with axillary lymph node metastasis and distance from tumor to nipple less than 4 cm are more susceptible to infiltration of breast cancer surface skin.