Pathologic aspects of inflammatory breast carcinoma: part 1. Histomorphology and differential diagnosis.

Inflammatory breast carcinoma (IBC) is rare, but it is the most aggressive variant of breast cancer. Because a diagnosis of IBC is usually based on the presence of typical clinical symptoms that are not always associated with certain pathologic characteristics, the diagnosis often presents a great challenge even to the most experienced clinicians. Even more, IBC has not been associated with a specific histologic tumor type. With recent epidemiologic and molecular evidence now suggesting that IBC is a distinct disease entity rather than a subtype of locally advanced breast cancer, the accurate differentiation of this disease has never been more crucial to ensuring appropriate treatment. The focus of this chapter is on the histomorphologic characteristics of IBC and its broad differential diagnosis.