Inflammatory breast cancer doesn't commonly form a lump, as occurs with other forms of breast cancer. Instead, signs and symptoms of inflammatory breast cancer include: 
Rapid change in the appearance of one breast, over the course of several weeks
Thickness, heaviness or visible enlargement of one breast
Discoloration, giving the breast a red, purple, pink or bruised appearance
Unusual warmth of the affected breast
Dimpling or ridges on the skin of the affected breast, similar to an orange peel
Tenderness, pain or aching
Enlarged lymph nodes under the arm, above the collarbone or below the collarbone
Flattening or turning inward of the nipple
 For inflammatory breast cancer to be diagnosed, these symptoms must have been present for less than six months.