Other carcinoma subtypes, WHO classified
Acinic cell

Topic Completed: 1 March 2012

Minor changes: 21 June 2020

Copyright: 2001-2019,, Inc.

PubMed search: acinic cell [title] carcinoma breast

Monika Roychowdhury, M.D.
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Cite this page: Roychowdhury M. Acinic cell. website. Accessed November 23rd, 2020.
Definition / general
  • Identical to salivary gland counterpart, has serous differentiation
  • These carcinomas show diffuse infiltrative growth patterns of small glandular structures and are composed of cells with a coarse granular or clear cytoplasm resembling acinar cells of the salivary glands or Paneth cells
  • See also Salivary Glands chapter
  • Although similar in some respects to secretory carcinoma (Histopathology 2002;40:223), it lacks its characteristic ETV6 gene rearrangement (Histopathology 2008;52:840)
  • Uncommon in breast, < 20 cases reported
Clinical features
Case reports
Gross description
  • Often well circumscribed but may be infiltrative
  • Gray pink and hemorrhagic cut surface
  • 2 - 5 cm
Gross images

Images hosted on other servers:

5.5 cm ill defined mass

Microscopic (histologic) description
  • Monotonous proliferation of cells with abundant finely granular, weakly eosinophilic or clear vacuolated cytoplasm, central round nuclei and prominent nucleoli, resembling acinic cells of salivary gland (J Clin Pathol 2003;56:497)
  • Cytoplasmic dark eosinophilic coarse granules (resembling Paneth cells) can be seen
  • Often clear cells
  • May have microglandular pattern (Virchows Arch 2000;437:74)
  • Up to 15 mitotic figures / 10 HPF
  • May be mixed with ductal carcinoma-like cells (Am Surg 2002;68:993)
Microscopic (histologic) images

Images hosted on other servers:

Various images

Tumor cells have prominent cytoplasmic granularity

Post chemo tumor
has cells with
clear vacuolated

Fig A / B

Salivary gland tumors:

Papillary fronds with hobnail cells and vacuolated cells

Microcystic and
solid patterns in
tumors from father
and daughter

Various images

Fig 1: Dedifferentiated parotid tumor with some classic areas
Fig 2: Mitotic figures and necrosis
Fig 3: Differentiated areas with basophilic cytoplasm and vesicular nuclei
Fig 4: PAS+ diastase resistant granules

Positive stains
Negative stains
Electron microscopy description
  • Multiple round, electron dense, cytoplasmic secretory granules
Electron microscopy images

Images hosted on other servers:

Electron dense granules

Clear cells in post
chemo patient
have dilated endo-
plasmic reticulum

Variably sized electron dense granules in the cytoplasm

Differential diagnosis
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Image 01 Image 02