Breast malignant, males, children
Other malignancies

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

Revised: 28 December 2016, last major update August 2012

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

PubMed Search: plasmacytoma breast
Cite this page: Plasmacytoma. website. Accessed June 17th, 2018.
Definition / general
  • Neoplasm of plasma cells, either primary to breast or secondary (most cases) to a systemic process or another plasmacytoma
  • Not part of WHO breast classification
Clinical features
  • Rare
  • May progress to multiple myeloma after years of remission
  • Frozen section diagnoses are often incorrect - resembles lobular or poorly differentiated tumor, but with a grossly well circumscribed appearance
Case reports
Clinical images

Images hosted on PathOut server:

Mammogram, courtesy of Dr. Mark R. Wick

Images hosted on other servers:

Well defined mass with irregular borders

Microscopic (histologic) description
  • Immature and mature plasma cells with nuclear pleomorphism
  • Also binucleated and multinucleated forms, mitotic figures and necrosis
Microscopic (histologic) images

Images hosted on PathOut server:

Courtesy of Dr. Mark R. Wick

Dense infiltrate of plasma cells and lymphocyes (AFIP)

Plasma cells (long arrows),
Russell bodies (short arrow)
and lymphocytes

Images hosted on other servers:


Cells are focally arranged in a linear fashion

Tumor in HIV+ man

With ductal carcinoma

HER2 negative

Plasma cells are IgA+ and kappa light chain+

Kappa staining

Diffuse Ki67 nuclear staining

Cytology description
  • Dispersed population of plasmacytoid cells at various stages of maturation (Acta Cytol 2003;47:1107)
  • Mature plasma cells have an eccentric nucleus and abundant deep basophilic cytoplasm with a paranuclear halo
  • Plasmablasts (immature plasma cells) have a prominent eccentric nucleus with a single large nucleolus and abundant deep basophilic cytoplasm with no paranuclear halo
  • Also binucleate and multinucleate forms (Acta Cytol 1997;41:364)
Differential diagnosis