Definition of Ductal Carcinoma In Situ (DCIS) and Lobular Carcinoma In Situ (LCIS)

• Ductal carcinoma in situ (DCIS):
  • Is noninvasive carcinoma of the breast
  • Is defined as:
    • The proliferation of malignant epithelial cells confined to the mammary ducts and without evidence of invasion through the basement membrane
    • Is an intra ductal proliferation of malignant epithelial cells within the tubulolobular system of the breast with no evidence of invasion across the basement membrane
  • Because it is noninvasive:
    • DCIS does not pose a risk of metastasis
  • There appears to be a continuum between flat epithelial atypia, atypical ductal hyperplasia (ADH), and DCIS:
    • With DCIS being the final step in the pathway prior to the development of invasive disease
  • Both clinical risk factors and molecular changes associated with malignant transformation:
    • Are similar between DCIS and invasive cancer
  • The coexistence of DCIS and invasive carcinoma within one lesion:
    • Suggests that DCIS acts as a precursor lesion to invasive carcinoma
  • Further evidence of the capacity to progress:
    • Is that half of all recurrences after breast-conserving surgery (BCS) for DCIS, with or without adjuvant treatment:
      • Are invasive.

• Lobular carcinoma in situ:
  • Although previously considered a form of noninvasive carcinoma:
    • Lobular carcinoma in situ (LCIS) is now understood to be:
      • A pathologic marker of increased bilateral breast cancer risk
  • Atypical lobular hyperplasia (ALH) and LCIS:
    • Are both forms of lobular neoplasia and, together with atypical ductal hyperplasia (ADH):
      • Represent proliferative nonmalignant breast lesions

#Arrangoiz #CancerSurgeon #BreastSurgeon #SurgicalOncologist #BreastCancer #LCIS #DCIS #DuctalCarcinomaInsitu #LobularNeoplasia #LobularCarcinomaInsitu #Surgeon #Teacher #Miami #Mexico #MSMC #MountSinaiMedicalCenter