PATHOLOGY OF BREAST TUMOURS

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PATHOLOGY OF BREAST TUMOURS
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TOPICS

• In situ carcinoma
• Special types of carcinoma
• Mixed tumours
• Prognosis
• Predicitive factors

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In situ carcinoma

• Ductal carcinoma in situ
• Lobular carcinoma in situ
• Mixed ductal/lobular carcinoma in situ
• Loss of e-cadherin immunoreactivity seems to be
  specific for LCIS

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In situ carcinoma

• Total mastectomy is generally curative
• If breast conserving surgery carried out, the
  risk in the ipsilateral breast is greater with
  DCIS
• Time to development of invasion is less in DCIS

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In situ carcinoma

• LCIS clinical follow up tamoxifen
• Most patients with DCIS do not go on to develop
  invasive ca risk reduced by DXT /- tamoxifen
• Risk in contralateral breast is greatest for LCIS

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In situ carcinoma

• DCIS
• Low grade Monomorphic, small nuclei (1-2 rbcs),
  diffuse chromatin, occasional nucleoli, polarised
• High grade markedly pleomorphic, more than 2.5
  rbcs, irregular vesicular chromatin, prominent
  multiple nuceloli
• Intermediate not low grade, not high grade

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In situ carcinoma

• ER status essential
• Assess invasion using collagen IV or laminin
• Microinvasion less than 1mm, often has a ductal
  NST pattern

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Van Nuys prognostic index

• Size 15mm or less 1 point, 1640mm 2, 41mm
  or more 3
• Margin 10mm or more 1, 1-9mm 2, less than 1
  3
• Pathology not HG, no necrosis 1, not HG,
  necrosis present 2, HG /- necrosis 3

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Van Nuys prognostic index

• Score 3 or 4 radiotherapy may not be necessary
• Score 5, 6, 7, radiotherapy necessary after local
  procedure
• Score 8, 9, mastectomy required to reduce high
  rate of local recurrence

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SPECIAL TYPES

• To qualify as special type, at least 90 of the
  tumour should show the diagnostic features (if
  less than 10 of the tumour is NST, still can
  qualify as special type)

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SPECIAL TYPES

• Lobular
• Classical
• Pleomorphic
• Alveolar

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SPECIAL TYPES

• Ductal
• Tubular/cribriform
• Mucinous
• Papillary
• Medullary
• Apocrine
• Squamous

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SPECIAL TYPES

• Metaplastic
• With endocrine features
• Small cell
• Secretory
• Cystic hypersecretory
• Adenoid cystic
• Lipid rich
• Glycogen rich
• Invasive micropapillary

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Papillary carcinoma

• The evaluation of papillary tumours requires
  evaluation of the epithelium between adjacent
  fibrovascular cores for the features of DCIS
• Most behave like DCIS
• Diagnosis of invasion may be difficult

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Medullary carcinoma

• A well circumscribed carcinoma composed of poorly
  differentiated cells with scant stroma and
  prominent lymphoid infiltration
• Many of these features seen in BRCA-1 carcinomas
• Morphological criteria must be strictly applied
  for favourable prognosis to apply

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Medullary carcinoma

• Microscopic features
• Lymphoplasmacytic reaction also at periphery
• Microscopic circumscription
• Syncytial sheets
• Poorly differentiated nuclear grade
• High mitotic rate
• Bloom and Richardson grade 3

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Mixed tumours

• If more than 50 of the tumour is of special
  type, then it should be recorded mixed
  lobular/ductal, mixed tubular/ductal etc

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Invasive micropapillary carcinoma

• May resemble mucinous carcinoma
• Appear to have a worse than average prognosis

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Nottingham Prognostic Index

• 0.2 x tumour size (cm) plus modified
  Bloom/Richardson grade (1-3) plus lymph node
  score (1-3)
• Lymph node score
• 1 0 nodes
• 2 1-3 nodes
• 3 4 nodes

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Nottingham Prognostic Index

• Tumour size
• Invasive only
• If multiple largest tumour only
• If bilateral, calculate for each side

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Predictive factors

• ER/PR and HER-2
• ER often sufficient if ER negative, PR may be
  helpful
• Should be done on all tumours and all cases of
  DCIS/LCIS
• Scoring systems H score and Quik score

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HER-2

• Human Epidermal Growth Factor
• Target of Herceptin treatment
• Immunohistochemistry
• Score as -, , ,
• is regarded as positive
• requires FISH presently sent to Glasgow