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Comedo type ductal carcinoma in situ

Radswiki and Stefano Pacifici et al.

A comedo-type ductal carcinoma in situ, also known as comedocarcinoma in situ, can be considered a subtype of ductal carcinoma in situ (DCIS). It completely fills the duct with plugs of tumour growth, which comes out in form of sebum to the squeezing, just as a comedone. They can account for ~ 60% of DCIS. It is the most aggressive of intraductal carcinomas. In 30% of cases it can be multicentric and / or multifocal.

Casting-type microcalcifications are the most frequent mammographic finding (78% of cases) in comedotype DCIS.

Histologically DCIS-comedo is diagnosed when at least one duct in the breast is filled and expanded by large, markedly atypical cells. Cases in which central necrosis occurs, meaning dead cells are found in the tissue, are described as "comedonecrosis".

It has the risk of occult infiltration. A comedo that extends for more than 2.5 cm has the combination of invasive component in 45% of cases .

Infiltrating ductal carcinoma (infiltrative ductal carcinoma with central necrosis) may so closely mimic the pattern of DCIS with central comedonecrosis that on initial morphological analysis these foci of tumours are often labeled as DCIS (high grade, comedo).