Gross cysts are the main pathologic lesion in gross cysticdisease, a prevalent premenopausal condition. Thegeneration of fluid secretion, which builds up in breastcysts, is its defining feature. A pathologic secretion from thebreast, gross cystic disease fluid is made up of manyglycoproteins, including the distinct 15 kDa monomerprotein GCDFP-15. Cells with apocrine functions, such asbreast cysts, and apocrine glands in the axilla, vulva, eyelid,and ear canal seem to be the only parts of the body thatmanufacture GCDFP-15. According to studies, the GCDFP-15 antibody is a very sensitive and specific indicator ofbreast cancer. About 70% of breast cancers exhibit positiveGCDFP-15 antibody staining. On the other hand,mesotheliomas and colorectal cancers do not stain withthis antibody. This antibody seldom stains lungadenocarcinomas.