Lobular neoplasia

Spectrum includes Atypical Lobular Hyperplasia (ALH) and Lobular Carcinoma In Situ (LCIS).

• Pathology: Loss of E-cadherin expression (CDH1 mutation).
• Clinical Significance:
  • Classic LCIS: Marker of generalized increased risk (bilateral).
  • Pleomorphic LCIS: More aggressive, treated like high-grade Ductal Carcinoma In Situ (DCIS).
• Imaging: Often incidental; LCIS rarely calcifies (unlike DCIS).