In oncology, a spiculated mass is a lump of tissue with spikes or points on the surface. It is suggestive but not diagnostic of malignancy, i.e. cancer.It's a common mammography finding in carcinoma breast. In oncology, a spiculated mass is a lump of tissue with spikes or points on the surface. It is suggestive but not diagnostic of malignancy, i.e. cancer.It's a common mammography finding in carcinoma breast. This article incorporates public domain material from the U.S. National Cancer Institute document 'Dictionary of Cancer Terms'.