Diffuse dermal angiomatosis (DDA) is a type of reactive skin angioproliferation. Clinically, this rare disorder presents as red-violet purpuric papules and/or plaques (some with a greater tendency towards necrosis and ulceration), which can be localized in any body area, but is most often seen in the upper and lower extremities. Localization in the breast commonly presents with severe intractable breast pain and characteristic reticular violaceous erythematous plaques with central ulcerations. Histological examination is fundamental for the diagnosis and is characterized by varied patterns of lobular or diffuse hyperplasia of endothelial cells at the extravascular level. The condition is associated with various underlying conditions, many of which result in local tissue ischemia. In this report, we present a patient with DDA with an underlying mass lesion of the breast, which proved to be an adjacent fat necrosis. Various treatments have proven beneficial, including revascularization, oral corticosteroids, smoking cessation, and isotretinoin. In this case, our patient benefited from secondary excision of the affected area.