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Breast malignant, males, children

In situ carcinoma

Pleomorphic lobular carcinoma in situ (PLCIS)

Reviewer: Monika Roychowdhury, M.D. (see Reviewers page)
Revised: 10 November 2012, last major update January 2012
Copyright: (c) 2001-2012, PathologyOutlines.com, Inc.


● Also called ductal-lobular carcinoma in situ
● Has features distinct from classic LCIS (Am J Surg Pathol 2009;33:1683)

Case reports

● 67 year old woman with mammographic calcifications, in situ and invasive disease (Case of Week #168)
● Almost pure signet ring cell morphology (Pathol Int 2006;56:683)

Treatment and prognosis

● May have more aggressive behavior than classic LCIS
● Treated similar to DCIS (excision with negative margins, variable radiation)
● Responded to trastuzumab in 4 cases (J Clin Oncol 2008;26:5823)

Micro description

● One or more lobular units with distended terminal ducts and acini
● Medium/large dyscohesive cells with eosinophilic, granular and occasionally vacuolated cytoplasm
● Often apocrine features (Hum Pathol 1992;23:655, Pathol Oncol Res 2002;8:151)
● Eccentrically placed nuclei are 4x size of lymphocytes, exhibit moderate/marked pleomorphism, distinct nucleoli
● Central necrosis in 60%, microcalcifications in 40%
● “Classic” LCIS is often seen
● Morphologic features of pleomorphic LCIS and coexisting invasive disease (if present) are similar

Micro images

Various images

Central necrosis and calcification

With infiltrating lobular carcinoma

Needle biopsy

In situ and invasive disease

E-cadherin: in situ and invasive disease

Fig A: moderate Ki-67, Fig B: E-cadherin negative

Negative E-cadherin with internal control (normal breast)

E-cadherin: LCIS vs. DCIS

Other images: Plasmacytoid cells in linear pattern (PDF)

Cytology description

● Features are hybrid of ductal and lobular tumor cells - cellular smears with tumor cells 2-3x size of classic invasive lobular, with moderate to abundant eosinophilic, granular/apocrine to finely vacuolated cytoplasm, moderate nuclear pleomorphism, prominent nucleoli; may have plasmacytoid appearance due to eccentric nuclear location (Journal of Cytology 2007; 24:193 - PDF)
Ductal lavage: epithelial cells in small clusters, single file arrangement or solitary, cytoplasmic vacuoles and nuclear atypia (Acta Cytol 2008;52:207)

Cytology images

Plasmacytoid cells (PDF)

Positive stains

● ER (90-100%), P120 catenin (cytoplasmic-dominant, Am J Surg Pathol 2008;32:1721)
● GCDFP-15 (74%), PR (50%), HER2 (5-25%), Ki-67 > 20% (47%)

Negative stains

● E-cadherin (100%), p53 (75%)

Molecular / cytogenetics description

● Molecular features are distinct from classic LCIS (Am J Surg Pathol 2009;33:1683), but resemble invasive lobular carcinoma more than invasive ductal carcinoma (J Pathol 2008;215:231)

Differential diagnosis

● DCIS: no lobular involvement, cells are cohesive, nuclei not eccentric, strongly E-cadherin+ (Arch Pathol Lab Med 2009;133:1116), pleomorphic cells are ER-, HER2+

Additional references

Mod Pathol 2002;15:1044

End of Breast malignant, males, children > In situ carcinoma > Pleomorphic lobular carcinoma in situ (PLCIS)

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