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

Author: Monika Roychowdhury, M.D. (see Authors page)

Revised: 18 October 2016, last major update January 2012

Copyright: (c) 2002-2016,, Inc.

PubMed Search: Pleomorphic lobular carcinoma in situ

Cite this page: Pleomorphic lobular carcinoma in situ (PLCIS). website. Accessed October 22nd, 2017.
Case reports
  • 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)
Microscopic (histologic) 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
Microscopic (histologic) images

Images hosted on PathOut server:

In situ and invasive disease

E-cadherin: in situ and invasive disease

Images hosted on other servers:

Various images

E-cadherin: LCIS vs. DCIS

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)
  • Ductal lavage: epithelial cells in small clusters, single file arrangement or solitary, cytoplasmic vacuoles and nuclear atypia (Acta Cytol 2008;52:207)
Positive stains
Negative stains
Molecular / cytogenetics description
Differential diagnosis
Additional references