2. Anatomy
• The adult female breast lies between the second and
sixth ribs and between the sternal edge and the mid
axillary line.
• It is composed of skin, subcutaneous tissue, and breast
tissue, with the breast tissue including both epithelial
and stromal elements. Epithelial elements make up
10% to 15% of the breast mass, with the remainder
being stroma.
• Each breast consists of 15 to 20 lobes of glandular
tissue supported by fibrous connective tissue.
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4. 4/5/2022 AJCC 8th Edition – Breast Carcinoma Staging 4
• Chest wall
• Axillary region
• Supraclavicular
fossa
5. Lymphatic Drainage
• It occurs through a superficial and deep lymphatic plexus,
• >95% of the lymphatic drainage axillary lymph nodes,
• remainder via the internal mammary nodes.
• 3 major routes:
• Axillary
• Inter pectoral
• Internal mammary
• The internal mammary nodes are located in the first six
intercostal spaces within 3 cm of the sternal edge, with the
highest concentration of internal mammary nodes in the first
three intercostal spaces.
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8. TNM STAGING
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• USED For:
• Ductal Carcinoma in Situ
• Invasive breast carcinoma
• NOT for:
• Breast Sarcoma
• Lymphoma
9. T1
T1: A tumor 20mm or less in greatest
dimension.
T1mi: A tumor 1 mm or less in greatest diameter.
T1a: A tumor more than 1 mm but not more than
5 mm in greatest dimension.
T1b: A tumor more than 5 mm but not more than
10 mm in greatest dimension.
T1c: A tumor more than 10 mm but not more
than 20mm in greatest dimension.
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10. T2
T2: Tumor more
than 20 mm but
not more than 50
mm in greatest
dimension.
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11. T3
T3: tumor more than
50 mm in greatest
dimension.
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12. T4
T4: A tumor of any size with direct
extension to chest wall and/or to
the skin (ulceration or skin
nodules).
T4a: is extension to the chest wall.
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13. T4b
T4b: edema ( including peau d’orange) of the skin, or ulceration of
the skin of the breast or satellite skin nodules confined to the
same breast.
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14. T4c
T4c: is defined as both
T4a and T4b.
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15. T4d
• T4d: Inflammatory breast carcinoma.
It’s defined as:
“clinical pathological entity characterized by diffuse
erythema and edema (peau d’orange) involving
approximately a third or more of the skin of breast.”
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16. Definition of Regional Lymph Nodes –
Clinical (cN) and Pathologic (pN)
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17. TERMS to be used:
• ITCs: (isolated tumor cell clusters) malignant cell clusters no larger
than 0.2 mm.
• Detected by routine histology or IHC methods.
• Micro metastases: approximately 200 cells, larger than 0.2 mm, but
none larger than 2.0 mm.
• Macro metastases: one node must contain tumor deposit larger
than 2mm, all remaining quantified nodes must contains micro
metastases (deposits larger than 0.2 mm).
• pN0(i+): ITCs (regardless of their number) , none larger than 0.2
mm.
• pN0(mol+): histologically negative nodes, but unique epithelial cell
markers are detected using molecular methods (PT-PCR).
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18. Regional Lymph Nodes—Clinical (cN)
• cNX: Regional lymph nodes cannot be assessed (e.g., previously removed)
• cN0: No regional lymph node metastases (by imaging or clinical examination)
• cN1: Metastases to movable ipsilateral level I, II axillary lymph node(s)
• cN1mic: Micro metastases (approximately 200 cells, larger than 0.2 mm, but none larger than
2.0 mm)
• cN2: Metastases in ipsilateral level I, II axillary lymph nodes that are clinically fixed
or matted or in ipsilateral internal mammary nodes in the absence of axillary lymph
node metastases
• cN2a: Metastases in ipsilateral level I, II axillary lymph nodes fixed to one another (matted) or to
other structures
• cN2b: Metastases only in ipsilateral internal mammary nodes in the absence of axillary lymph
node metastases
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19. Regional Lymph Nodes—Clinical (cN)
• cN3: Metastases in ipsilateral infraclavicular (level III axillary)
lymph node(s) with or without level I, II axillary lymph node
involvement; or in ipsilateral internal mammary lymph node(s)
with level I, II axillary lymph node metastases; or in ipsilateral
supraclavicular lymph node(s) with or without axillary or internal
mammary lymph node involvement
• cN3a: Metastases in ipsilateral infraclavicular lymph node(s)
• cN3b: Metastases in ipsilateral internal mammary lymph node(s) and
axillary lymph node(s)
• cN3c: Metastases in ipsilateral supraclavicular lymph node(s)
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21. Regional Lymph Nodes—Pathologic
(pN)
• pNX: Regional lymph nodes cannot be
assessed
• pN0: No regional lymph node
metastasis identified or ITCs only
• pN0(i+): ITCs only (malignant cell
clusters no larger than 0.2 mm) in
regional lymph node(s)
• pN0(mol+): Positive molecular findings
by RT-PCR; no ITCs detected
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22. pN1
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pN1mi: Micro metastases (approximately 200
cells, larger than 0.2 mm, but none larger than
2.0 mm)
pN1a: Metastases in 1–3 axillary lymph nodes,
at least one metastasis >2.0 mm
pN1b: Metastases in ipsilateral internal
mammary sentinel nodes,
pN1c: pN1a and pN1b combined
23. pN2:
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pN2a: Metastases in 4–9 axillary lymph nodes (at least one macro deposit)
pN2b: Metastases in clinically detected internal mammary lymph nodes with
or without microscopic confirmation; with pathologically negative axillary
nodes.
24. pN3
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pN3a: Metastases in 10 or more axillary lymph nodes (at least one tumor
deposit >2.0 mm); or metastases to the infra clavicular (level III axillary
lymph) nodes
pN3b: pN1a or pN2a in the presence of cN2b (positive internal mammary
nodes by imaging); or pN2a in the presence of pN1b
pN3c: Metastases in ipsilateral supraclavicular lymph nodes
25. Distant Metastases (M)
• M0: No clinical or radiographic evidence of distant metastases.
• cM0(i+): No clinical or radiographic evidence of distant metastases in
the presence of tumor cells or deposits no larger than 0.2 mm
detected microscopically or by molecular techniques in circulating
blood, bone marrow, or other non-regional nodal tissue in a patient
without symptoms or signs of metastases.
• cM1: Distant metastases detected by clinical and radiographic means.
• pM1: Any histologically proven metastases in distant organs; or if in
non-regional nodes, metastases greater than 0.2 mm.
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AJCC
Stage
Grouping
T1: IA
T2: IIA
T3: IIB
T4: IIIB
N1Mi: IB
N1: IIA
N2: IIIA
N3: IIIC
T2 + N1: IIB
T3 + N1: IIIA
M1: IV
