Case 10 Answer 2
Infiltrating Ductal Carcinoma with necrosis. Although the classic cystic cancer is Intracystic Papillary Carcinoma, they are very rare compared to the more common Infiltrating Ductal, NOS, and fluid aspirated from these tumors is usually bloody. This and the fact that this cystic mass previously yielded a negative aspirate make it more likely to be the more common IDC with necrosis. The necrotic center of a cancer is much more likely to yield a negative result. This is why core biopsy should be aimed at the solid portions of the mass.
Aspiration usually produces minimal bleeding, so a hematoma should be small and should be resolved by 3 months time. The patient had no symptoms of infection, and this nodular mass-like appearance would be unusual for an abscess.