Historically, the presence of skin involvement results in the classification of a breast carcinoma into the highest tumor category, or accordingly into the highest non-metastatic disease stage (current TNM classification: T4/stage III). However, probably the most important criterion of the TNM classification system is the basic rule that tumors exhibiting similar extension and prognosis should be grouped into one category. Newer studies indicate the need to revise the current TNM system, since grouping all tumors demonstrating "skin involvement" together results in the combination of tumors with widely differing prognostic and therapeutic implications into a single group. Thus, our recommendation is that breast carcinomas classified under the TNM categories T4a-c should be only grouped together according to tumor size. Only the prognostically very unfavorable inflammatory carcinomas (T4d) should be maintained in the T4 category.