Which breast cancer mimics mastitis and has a poor prognosis due to invasion of the skin lymphatics?

• A. Inflammatory breast cancer
• B. Ductal carcinoma in situ
• C. Invasive ductal carcinoma
• D. Fibroadenoma

Answer: (A)

Inflammatory breast cancer presents with signs that closely mimic mastitis—redness, warmth, swelling, and often rapid breast enlargement—without a discrete lump. The key feature is tumor emboli blocking the dermal lymphatics, which causes edema and the skin changes described as peau d’orange. This dermal lymphatic invasion is what drives the aggressive behavior and explains the poor prognosis, since cancer spreads early and the disease can appear like an infection, delaying diagnosis.

Ductal carcinoma in situ is non-invasive and typically shows calcifications or a suspicious lesion on imaging, without the skin changes caused by lymphatic obstruction, so it doesn’t mimic mastitis or drive prognosis through dermal lymphatic invasion. Invasive ductal carcinoma can invade surrounding tissue and may present as a mass with variable skin involvement, but its prognosis isn’t characteristically tied to dermal lymphatic invasion of the skin in the same way. Fibroadenoma is benign, usually a well-circumscribed, mobile lump, and lacks inflammatory skin signs.