Salivary glands
Primary salivary gland neoplasms
Malignant
Acinic cell carcinoma


Topic Completed: 1 August 2011

Minor changes: 5 January 2021

Copyright: 2002-2021, PathologyOutlines.com, Inc.

PubMed Search: Acinic cell carcinoma[TI] salivary[TI]

F. Zahra Aly, M.D., Ph.D.
Jen-Fan Hang, M.D.
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Cite this page: Aly FZ, Hang JF. Acinic cell carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/salivaryglandsaciniccell.html. Accessed January 19th, 2021.
Definition / general
  • 1 - 3% of all salivary gland tumors; 3% of all parotid salivary gland tumors
  • #2 childhood salivary gland malignancy after mucoepidermoid carcinoma
  • Usually parotid and minor salivary glands, also parotid lymph nodes
  • 10 - 15% metastasize (usually to local lymph nodes), 10 - 30% recur (may be due to inadequate excision)
  • 80 - 90% recur if incompletely excised
  • 5 year survival 90%, 20 year survival 60%
  • Less aggressive in minor salivary glands
Poor prognostic factors
  • High stage, pain or fixation, gross invasion, desmoplasia, anaplasia or dedifferentiated component, increased mitotic figures, necrosis, neural invasion, incomplete resection, large size, involvement of deep lobe of parotid, multinodularity
Case reports
Gross description
  • Encapsulated, tanish gray, firm to soft, solid / cystic; usually < 3 cm
  • 3% bilateral or multicentric
Microscopic (histologic) description
  • At scanning power, basophillia and prominent lymphoid infiltrate should raise suspicion of acinic cell carcinoma
  • Tumor shows multidirectional differentiation towards acinar, ductal as well as myoepithelial elements
  • Some tumor cells must demonstrate differentiation towards acinar cells
  • Variable patterns: solid, microcystic, papillary cystic (associated with hemorrhage), follicular
  • Variable cell types: uniform acinar (serous) type cells with basophilic granular cytoplasm, clear cells (hypernephroid pattern, contains glycogen or mucin), vacuolated, intercalated duct, nonspecific glandular cells (smaller, syncytial)
  • Few mitotic figures
  • May have prominent lymphoid follicles at periphery (lymphoid stroma), psammoma bodie
Microscopic (histologic) images

Case #355

Various images

Cytology description
  • Sheets or loosely cohesive cells without regular acinar organization
  • Plump tumor cells with abundant granular to vacuolated cytoplasm, indistinct cell borders and variable zymogen secretory granules best seen on Romanowsky type stain
  • Minimal nuclear atypia and frequent naked nuclei
Cytology images

Contributed by Jen-Fan Hang, M.D.

Loose clusters

Intracytoplasmic
zymogen granules



Case #355

Various images

Positive stains
Electron microscopy description
  • Multiple round, electron flocculent material with variable granule density (dependent on fixation), cytoplasmic secretory granules
Differential diagnosis
  • Normal parotid gland: tumors lack striated and interlobular ducts, lack lobular architecture
  • Thyroid carcinoma
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