Mammary hamartoma

Mammary hamartoma, also breast hamartoma, is an uncommon benign pathology of the breast.

General

• Benign.
• Disordered growth - see hamartoma.

Gross

• Well-circumscribed - key feature.

Microscopic

Features:

• Disordered arrangement of ductal and lobular structures.
• Normal arrangement of cells with in the ductal structures, i.e. myoepithelium and epithelium present.
• Variable features:
  1. Adipose tissue - predominant.
  2. Dense fibrosis tissue - predominant.
  3. Cystic glandular dilation.

Notes:

• If adipose tissue predominates; it may be labeled adenolipoma.

DDx:

• Fibroadenoma - may have adipose tissue.
• Phyllodes tumour - may have adipose tissue.
• Pseudoangiomatous stromal hyperplasia.
• Fibrocystic changes.

Images

• Mammary hamartoma (breastpathology.info).
• Mammary hamartoma (nih.gov).

IHC

• None - it's a H&E diagnosis.

See also

• Breast pathology.
• Hamartoma.