What is a characteristic feature of Comedo Ductal Carcinoma in situ?

A characteristic feature of Comedo Ductal Carcinoma in situ (DCIS) is the presence of exudate that is often described as a yellow-tan soft material coming from the ducts. This type of DCIS is known for its high-grade characteristics and can lead to necrosis within the ducts, resulting in the accumulation of necrotic cells and possibly debris that can appear as a yellow-tan substance when sampled. The formation of this material is indicative of the disease process and aids in distinguishing it from other types of ductal carcinoma in situ.

In the context of the other options, while DCIS is sometimes found incidentally in biopsies, it is not always the case. Moreover, serous or bloody discharge can occur, but they are not definitive characteristics of comedo DCIS specifically. Lastly, while DCIS is frequently unilateral and can exhibit necrosis, noting it as bilateral without necrosis does not accurately represent its clinical presentation and distinguishing features. Thus, the exudation of yellow-tan soft material from ducts is a telling indicator of comedo DCIS.