Ductal carcinoma in situ (DCIS): pathological features, differential diagnosis, prognostic factors and specimen evaluation.

Ductal carcinoma in situ (DCIS) is a heterogeneous, unicentric precursor of invasive breast cancer, which is frequently identified through mammographic breast screening programs. The lesion can cause particular difficulties for specimen handling in the laboratory and typically requires even more diligent macroscopic assessment and sampling than invasive disease. Pitfalls and tips for macroscopic handling, microscopic diagnosis and assessment, including determination of prognostic factors, such as cytonuclear grade, presence or absence of necrosis, size of the lesion and distance to margins are described. All should be routinely included in histopathology reports of this disease; in order not to omit these clinically relevant details, synoptic reports, such as that produced by the College of American Pathologists are recommended. No biomarkers have been convincingly shown, and validated, to predict the behavior of DCIS till date.