Atypical lobular hyperplasia

Atypical lobular hyperplasia, abbreviated ALH, a pre-malignant change in the breast characterized by cellular proliferation and cellular dyscohesion.

Atypical lobular hyperplasia
Diagnosis in short
Atypical lobular hyperplasia. H&E stain. (WC/Nephron)
LM DDx	lobular carcinoma in situ, lobular carcinoma
IHC	E-cadherin -ve
Site	breast
Prognosis	benign

It can be seen as the precursor to lobular carcinoma in situ, the precursor of lobular carcinoma.

General

• May occur with ductal involvement by cells of atypical lobular hyperplasia (abbreviated DIALH).
  • ALH with DIALH has a risk of developing breast cancer that is similar to LCIS.

Microscopic

Features:

1. Morphologic changes - memory device ABCDEF:
   • Atypia minimal - usually.
     • Relatively small ~1-2x size lymphocyte.
   • Borders of cells distinct/visible - dyscohesive.
   • Clear cytoplasm (focal).
     • May have a signet ring cell-like appearance.
   • Distend duct.
   • Eccentric nucleus, usu. round.
   • Filled ducts.
     • No luminal spaces - key feature.
       • Partially filled ducts are not LCIS.
2. Limited extent: <50% of terminal duct lobular unit (TDLU) is involved.

DDx:

• Lobular carcinoma in situ.
• Lobular carcinoma.

Images

• 

  ALH - low mag. (WC)

• 

  ALH - intermed. mag. (WC)

• 

  ALH - high mag. (WC)

• 

  ALH - E-cadherin - intermed. mag. (WC)

• 

  ALH - E-cadherin - high mag. (WC)

• 

  Benign breast - E-cadherin - intermed. mag. (WC)

• 

  Benign breast - E-cadherin - high mag. (WC)

• 

  Benign breast - E-cadherin - high mag. (WC)

IHC

• E-cadherin -ve or incomplete membrane staining.

See also

• Non-invasive breast carcinoma.