Invasive lobular carcinoma of the breast is a distinct histologic type with specific clinical, radiologic, and microscopic features, which is increasing in incidence in the Western World. Routine pathologic prognostic factors, including grade, lymph node stage, and size are of significance in predicting outcome in this group of patients who, overall, have survival comparable to those with other subtypes of breast cancer. Variants, however, are seen and these, as well as other standard factors such as histologic grade, have prognostic significance and should be recorded in pathology reports.