This case illustrates a highly suspicious lesion depicted on the routine mammogram which, regardless the result of the biopsy, should be excised. US-guided core biopsy confirmed an invasive carcinoma. 

MACROSCOPIC DESCRIPTION: "Right breast 3 o'clock 3cm from the nipple, Cat A": Tan white and brown needle cores 13mm in aggregate. A1.

MICROSCOPIC DESCRIPTION: Sections show predominantly fibrous stroma with small fatty areas. There are malignant cells both singly and a nested and linear architecture set within a desmoplastic stroma. The cells have pleomorphic hyperchromatic nuclei and mitoses are abundant. There is moderate background inflammation. An in-situ component contains comedo necrosis.

DIAGNOSIS: Right breast biopsy, 3 o'clock: Invasive carcinoma, grade 3.