Non-invasive breast carcinoma

Non-invasive breast cancer is a common entity... since the introduction of radiologic breast screening.

It can neatly be divided into the discussion of two entities:

• Ductal carcinoma in situ, and,
• Lobular carcinoma in situ.

Ductal carcinoma in situ

General

• Abbreviated DCIS.
• Diagnosis based on nuclear abnormalities and architecture.
• It is typically picked-up during radiologic screening.

Subtypes

Subtypes are based on architecture:

• Solid.
  • No spaces between cells.
• Cribriform.
  • Honeycomb-like appearance: circular holes.
  • "Cookie cutter" appearance/"punched-out" appearance/"Roman bridges" -- cells surround the circular holes.
• Papillary.
  • Papillae with fibrovascular cores.
• Micropapillary.
  • Small papillae without fibrovascular cores.
  • Have "drum stick" shape.

NOTE: comedonecrosis - used to be considered a separate subtype -- essentially solid type DCIS with necrosis.

Histologic features

• Nuclear pleomorphism -- most important feature.
• Nuclear size - compared to RBCs to grade DCIS.
  • Compare sizes of nuclei if you cannot find RBCs.
    • See Grading DCIS for details.
• +/-Mitoses.
• Cells cohesive.
  • No spaces in between.
  • Nuclei spaced equally.

Size criteria for DCIS

DCIS must meet the following size criteria:

• 2 membrane bound spaces -- OR -- 2 mm.
• If it isn't DCIS... it's atypical ductal hyperplasia (ADH).

The treatment is similar; ADH and DCIS are both excised.

The differences are:

• DCIS is cancer, i.e. this has life insurance implications.
• Radiation treatment - DCIS is irradiated; ADH does not get radiation.

Grading DCIS

Graded 1-3 (low-high) - compare lesional nuclei to one another.

• Grade 1
  • Nuclei 2-3x size of RBC.
  • NO necrosis.
• Grade 2
  • Nuclei 2-3x size of RBC.
  • +/-Necrosis.
• Grade 3
  • Nuclei >3x size of RBC.
  • Necrosis usually present.

Notes:

• It is often hard to find RBCs when you want 'em. DCIS is pleomorphic.
• If no RBCs are present to compare with compare the nuclei to one another.
• If you see nuclei >3x larger than their neigbour you're ready to call DCIS Grade 3.

FEHUT vs ADH vs DCIS

• Breast duct lumen with too many cells.
• This is common problem is breast pathology.

Definitions:

• EHUT = epithelial hyperplasia of the usual type, aka florid epithelial hyperplasia of the usual type (FEHUT).
• ADH = atypical ductal hyperplasia.
• DCIS = ductal carcinoma in situ.

• Mnemonic CLEAN = cell uniformity, luminal spaces, extent/size, arch., nuclei.
  • CELLULAR COMPOSITION:
    • EHUT = varied,
    • ADH = focal uniformity,
    • DCIS = uniform.
  • LUMINA:
    • EHUT = slits/irregular spaces,
    • ADH = irregular spaces, no slits,
    • DCIS = circular "punched-out".
  • EXTENT:
    • EHUT = usually lobulocentric,
    • ADH = limited extent.
    • DCIS = extensive.
  • ARCHITECTURE:
    • EHUT = irregular/swirling,
    • ADH = DCIS-like,
    • DCIS = DCIS architecture (solid, cribriform, comedo, papillary, micropapillary).
  • NUCLEI:
    • EHUT = variable,
    • ADH = hyperchromatic + uniform,
    • DCIS = evenly spaced.

Tabular comparison

Comparison of EHUT, ADH and DCIS:

	EHUT	ADH	DCIS
Cellular composition	varied	focal uniformity	uniform
Lumina	slits/irregular spaces	irregular spaces, no slits	circular "punched-out"
Extent	usually lobulocentric	limited extent	extensive
Architecture	irregular/swirling	DCIS-like	DCIS architecture (solid, cribriform, papillary, micropapillary)
Nuclei	variable	hyperchromatic & uniform	evenly spaced

Treatment - implications:

• EHUT - nothing; EHUT is benign.
• ADH - simple excision, i.e. lumpectomy.
• DCIS - excision (lumpectomy) + radiation.
• Invasive ductal carcinoma - excision with sentinel lymph node disection and radiation.

Lobular carcinoma in situ

• Abbreviated LCIS.
• Management is currently some matter of debate.
• Not detected radiologically - it is an incidental pathologic finding.

See also

• Breast
• Invasive breast cancer