Cancerisation of the lobules (CL), the intra-luminal extension of carcinoma from ducts and ductules into the breast lobules, is not often encountered in clinical practice. A retrospective study of eight individuals diagnosed with CL and ductal carcinoma in situ (DCIS) or cancer of the breast between 1999 and 2006 was undertaken to determine the management of the disease and patient outcomes. In most cases, breast conservation surgery with postoperative radiotherapy or mastectomy and systemic therapy were the chosen methods of treatment. None of the patients experienced tumour relapse or progression during a mean follow-up period of 40.6 (range 8–90) months. The management philosophy for this particular neoplastic condition should be based on the understanding that CL, when detected with DCIS or invasive breast cancer, may represent more extensive disease. Moreover, the finding of such histopathology underlines the need for meticulous attention to the resection margins and additional treatment as indicated.