Diffuse dermal angiomatosis (DDA) is a cutaneous reactive angiomatosis. Typically presenting as ulcerated, erythematous, violaceous, or purpuric plaques on the breast or lower extremities, DDA is believed to be a reaction to tissue ischemia. Granuloma inframammary adultorum (GIA) is a type of irritant dermatitis of multifactorial etiology, clinically presenting as papules and nodules. Herein, we report an interesting rash presenting as fungiform papulonodules overlying a large violaceous plaque on the left breast. Biopsy revealed an exuberant epidermal proliferation and a diffuse and deep dermal proliferation, consisting of small slit-like blood vessels in between collagen bundles. In light of these clinical and histopathologic findings in the setting of an indurated plaque on a pendulous breast of a woman with multiple risk factors for local tissue ischemia, a diagnosis of concurrent diffuse angiomatosis of the breast (DDAB) and GIA was rendered. This case highlights the critical importance of clinicopathologic correlation in the diagnosis of multiple diagnostic entities.