Invasive breast carcinoma of no special type
- Lesion
The usual breast cancer: a hard, gritty, irregular lump that can pull in the skin or nipple and spreads first to the armpit nodes, later to bone and lung.
What it is
Invasive carcinoma of no special type, formerly invasive ductal carcinoma, makes up most breast cancers. It is diagnosed by exclusion when the tumour does not show enough of a special pattern. It forms a hard, irregular, gritty mass with an infiltrative edge, invading as cords, nests and glands in a desmoplastic stroma without myoepithelial cells. It is graded by tubule formation, nuclear pleomorphism and mitoses. Spread is first to axillary lymph nodes, and later to bone, lung, liver and brain.
Structure
- Infiltrating cords, nests, trabeculae and glands of tumour cells in dense, sometimes elastotic, stroma.
- No myoepithelial layer around the invasive nests.
- Accompanying DCIS is common at the edge of the tumour.
- Lymphovascular invasion appears as tumour cells within endothelial-lined spaces around the tumour.
Step by step
- Tumour cells break through the myoepithelial layer and basement membrane of the duct.
- They induce a desmoplastic stroma that makes the mass hard and contracts it, pulling on ligaments and ducts.
- Cells enter lymphatics and reach the sentinel axillary node, then further nodes.
- Blood-borne spread seeds bone, lungs, liver and brain, sometimes years later.
- Blocked dermal lymphatics cause oedema with skin pitting (peau d'orange) or the diffuse redness of inflammatory carcinoma.
Markers
- ER, PR and HER2 on every tumour
- Ki-67
- GATA3 (breast origin in metastases)
- p63 and calponin (absence confirms invasion)
Clinical notes
- Presents as a painless hard lump, sometimes fixed to skin or chest wall, or as a screen-detected density.
- Axillary node status is the single most important prognostic factor in operable cancer.
- In Colombia and Latin America, more patients present with large tumours or nodes than in high-income countries, and early detection improves survival.
Test yourself
Think of the answer, then tap the question to see it.
What three features make up the Nottingham grade?
Tubule formation, nuclear pleomorphism and mitotic count.
What causes peau d'orange?
Tumour blocking dermal lymphatics, so the skin swells around the tethered hair follicles.
What is the most important prognostic factor in operable breast cancer?
The status of the axillary lymph nodes.
Elsewhere in DurgiPedia
Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Breast Cancer Treatment (PDQ®)–Health Professional Version (National Cancer Institute, 2026); Stage at diagnosis and stage-specific survival of breast cancer in Latin America and the Caribbean: A systematic review and meta-analysis (PloS one, 2019).
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Representative model, for educational purposes only.