Invasive lobular carcinoma

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Invasive lobular carcinoma
Diagnosis in short

Lobular carcinoma. H&E stain.
LM DDx invasive ductal carcinoma of the breast with lobular features, poorly differentiated carcinoma, LCIS
IHC E-cadherin -ve, usu. ER and PR +ve, HER2 -ve, CK7 +ve
Grossing notes breast grossing
Staging breast cancer staging
Site breast - see invasive breast cancer

Syndromes hereditary diffuse gastric cancer

Prevalence relatively common
Clin. DDx other breast tumours

Invasive lobular carcinoma, abbreviated ILC, is the second most common form of Invasive breast cancer.

It may be referred to as lobular carcinoma; however, this may lead to confusion with lobular carcinoma in situ.

General

  • May be associated with a CDH1 mutation - seen in diffuse type gastric cancer.[1][2]

Microscopic

Features:

  • "Single file" - cell line-up in a row.
    • Cell should not be cohesive -- lymphoma should briefly come to mind.
      • primary lymphoma of the breast exists... but it is extremely rare.
  • NO gland formation.
    • If it forms glands... it is more likely NST.
  • May have signet ring morphology.
  • NO desmoplastic reaction, i.e. the stroma surrounding the tumour cells should look benign and undisturbed.

Note:

  • Commonly have low grade nuclear features.

DDx:

Subclassification

  • Classic lobular carcinoma.
    • Low nuclear grade - NO significant variation of nucleus size.
  • Pleomorphic lobular carcinoma.
    • Significant nuclear atypia.

Note:

  • Some pathologist grade lobular carcinoma like other types and avoid the term "pleomorphic lobular carcinoma."[3]

Other variants:

  • Histiocytoid.[4]

Images

IHC

Features:

Others:

  • CK20 -ve.

See also

References

  1. URL: http://www.asco.org/ascov2/Meetings/Abstracts?&vmview=abst_detail_view&confID=65&abstractID=33006. Accessed on: 19 April 2011.
  2. Online 'Mendelian Inheritance in Man' (OMIM) 192090
  3. MUA. Jan 22, 2009.
  4. Tan, PH.; Harada, O.; Thike, AA.; Tse, GM. (Aug 2011). "Histiocytoid breast carcinoma: an enigmatic lobular entity.". J Clin Pathol 64 (8): 654-9. doi:10.1136/jcp.2011.088930. PMID 21398688.