The staging of invasive SPC is determined by the size of the invasive component, with Nottingham grading and estrogen and progesterone receptor and HER2/neu studies performed on the invasive tumor component [1,2,7]. Immunohistochemistry can be useful in the diagnosis and analysis of SPCs. Approximately 50% of SPCs are immunopositive for neuroendocrine markers, such as chromogranin and synaptophysin, reactivities that are rare in DCIS and florid ductal hyperplasia. This evidence concerns the gene SYP and ductal breast carcinoma in situ.