Breast malignant, males, children
Carcinoma subtypes
Neuroendocrine carcinoma - general

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

Revised: 1 October 2018, last major update August 2012

Copyright: (c) 2002-2018,, Inc.

PubMed Search: Neuroendocrine carcinoma [title] breast
Cite this page: Roychowdhury, M. Neuroendocrine carcinoma - general. website. Accessed December 17th, 2018.
Definition / general
  • Often (although not consistently) refers to cases lacking another specific histologic type, such as solid papillary, mucinous / colloid or micropapillary
  • Also called endocrine carcinoma or solid cohesive neuroendocrine carcinoma
  • Some cases were formerly called carcinoid tumor (Eur J Surg Oncol 1995;21:609)
Clinical features
  • Up to 5% of all breast carcinomas, depending on how defined
  • Frequency increases with age
  • Similar clinical presentation as ductal NOS; i.e. no carcinoid syndrome is present
  • Similar prognosis as ductal NOS
  • Apocrine phenotype (androgen receptor positive in 50% of cells) is present in elderly women (Mod Pathol 2001;14:768)
Case reports
Clinical images

Images hosted on other servers:

10 cm mass

Gross description
  • No distinctive gross features
Microscopic (histologic) description
  • Small, low grade tumor cells in nests separated by fibrous tissue
  • Rarely ribbons, rosettes or mitotic figures
  • Usually no mucin, no DCIS
  • No specific histologic patterns, such as solid papillary, small cell or mucinous / colloid
Microscopic (histologic) images

Images hosted on PathOut server:

Ribbon growth pattern with spindled cells (AFIP )

Cells often have argyrophilic
grimeliius+ granules, tumor is
immunoreactive for chromogranin (AFIP )

Images courtesy of Dr. Semir Vranic

Focal mucin production

Chromogranin expression

Synaptophysin expression

Estrogen receptor

HER2 protein

Images hosted on Flickr:

Neuroendocrine carcinoma of the breast

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Cells in small and large nests

No pleomorphism

Hint of lumen

Well differentiated tumor with alveolar growth pattern

Fig 2: H&E, chromogranin & synaptophysin

Chromogranin immunoreactivity

Various markers (Fig G, H, I)

(Fig A-D, H-I)

Carcinomatous lymphangitis


Cytology description
  • Markedly cellular with mostly dispersed tumor cells, also some loose clusters, acinus-like formations, small sheets, rosette like formations and ribbons
  • Cells are small and regular with moderate cytoplasm, fairly uniform and round / oval nuclei, often plasmacytoid with eccentric nuclei (Acta Cytol 1994;38:73, Indian J Pathol Microbiol 2007;50:65)
Positive stains
Electron microscopy description
  • Dense core secretory granules
Electron microscopy images

Images hosted on PathOut server:

Dense core granules
throughout the
cytoplasm, but increased
at cell membrane

Dense core granules
measure 270 - 430 nm
cluster near cell membrane

Differential diagnosis