The present study included 97 (89.8%) classic-type and 11 (11.1%) pleomorphic-type ILCs; the latter were significantly associated with an older patient age (p = 0.011), higher nuclear grade (p < 0.001), higher histologic grade (p < 0.001), higher pathologic tumor stage (p = 0.048), progesterone receptor (PR) negativity (p = 0.018), human epidermal growth factor receptor 2 (HER-2) positivity (p = 0.002), higher Ki-67 labeleing index (LI) (p = 0.001), and non-luminal A subtype (p < 0.001) when compared with the former. The gene discussed is ERBB2; the disease is neoplasm.