Neuroendocrine carcinoma

Small cell

Topic Completed: 1 August 2012

Minor changes: 19 March 2021

Copyright: 2002-2021,, Inc.

PubMed Search: small cell carcinoma breast

Monika Roychowdhury, M.D.
Page views in 2020: 2,375
Page views in 2021 to date: 1,721
Cite this page: Roychowdhury M. Small cell. website. Accessed October 25th, 2021.
Definition / general
  • Similar morphologically to lung tumor
  • Diagnosis requires exclusion of other primaries or presence of DCIS
  • Also known as oat cell carcinomas, high grade neuroendocrine carcinoma, small cell undifferentiated carcinoma
  • May arise as variant of metaplastic carcinoma or from multipotential stem cells capable of divergent differentiation (Surg Today 2008;38:734)
  • Prognosis may not be as poor as previously thought (Am J Surg Pathol 2000;24:1231)
  • Rare, usually ages 43 - 70 years
Case reports
Gross description
  • Mean 3 cm, range 1 - 5 cm
Gross images

Contributed by Dr. Mark R. Wick
Microscopic (histologic) description
  • Typical small cell carcinoma features of scant cytoplasm, small (diameter of three lymphocytes) nuclei with finely granular, evenly distributed chromatin and absent or inconspicuous nucleoli
  • Frequent mitoses
  • Frequent crush artifact or nuclear streaming
  • Infiltrative borders, lymphatic tumor emboli and necrosis
  • Associated with invasive poorly differentiated carcinoma and lobular carcinoma
  • Associated with small cell in situ carcinoma and high grade DCIS
Microscopic (histologic) images

Contributed by Dr. Mark R. Wick

Images hosted on other servers:


Neurone specific enolase+

H&E, p63, synaptophysin, TTF1

Classic features

Classic features (lung)

Cytology description
Cytology images

Contributed by Dr. Mark R. Wick


Positive stains
Negative stains
Molecular / cytogenetics description
  • Small study shows similar genetic changes as both invasive ductal carcinoma and lung small cell carcinoma (Hum Pathol 2001;32:753)
Differential diagnosis
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