What skin change of the breast would necessitate immediate referral for evaluation of breast cancer?

Peau d'orange, or "orange peel" skin, is a specific skin change that can indicate the presence of underlying breast cancer, particularly inflammatory breast cancer. This condition presents as a thickening of the skin and a dimpled appearance resembling the texture of an orange. It is often associated with underlying malignancy due to lymphatic blockage caused by cancerous cells, leading to swelling and changes in skin texture. This symptom is concerning enough to warrant immediate referral for further evaluation, including imaging and possible biopsy, as it may indicate a more aggressive type of breast cancer that requires prompt attention.

Other skin changes, while they may also raise concern, typically do not have the same level of urgency tied to them as peau d'orange. Localized redness might occur for various benign reasons, such as infection or irritation, dryness of the nipple can be related to dermatological conditions, and flexible skin is usually not indicative of malignancy. Thus, peau d'orange stands out as an urgent and serious indicator that necessitates prompt referral for further investigation.