Which statement about invasive ductal carcinoma histology is NOT correct?

• A. It features malignant ductal cells with desmoplastic stroma and invasion
• B. It demonstrates invasion into adjacent tissue
• C. It is characterized by a prominent lobular growth pattern
• D. It may be associated with ductal carcinoma in situ components

Answer: (C)

Invasive ductal carcinoma histology is defined by malignant ductal cells that invade through the surrounding tissue, typically provoking a desmoplastic (fibrous) stromal reaction as the tumor breaches the basement membrane. This invasion into adjacent breast tissue is a hallmark feature and helps differentiate invasive disease from in situ processes.

It is common for invasive ductal carcinoma to be associated with ductal carcinoma in situ components, reflecting a history of preinvasive disease adjacent to or within the tumor.

The statement describing a prominent lobular growth pattern is not correct for invasive ductal carcinoma. Lobular growth patterns are characteristic of invasive lobular carcinoma, which often shows single-file infiltration and less desmoplasia, and is frequently associated with E-cadherin loss.