Head and neck cytopathology

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Head and neck cytopathology is a small part of cytopathology. Non-cytopathology head & neck pathology is dealt with in the head and neck pathology article.

Thyroid cytopathology is dealt with in the thyroid cytopathology article. An introduction to cytopathology is in the cytopathology article.

Salivary gland cytopathology and salivary gland cytology redirect to here.

Proposed Milan system for reporting salivary gland cytopathology

Milan system and Milan classification redirect here.
Category Typical management Comments
Nondiagnostic repeat FNA
Nonneoplastic follow-up/discharge
Atypia of undetermined significance (AUS) repeat FNA use should be minimized
- like FLUS and ASCUS
Neoplasm excision subdivided into: (a) benign (b) salivary gland neoplasm of uncertain malignant potential (SUMP)
Suspicious for malignancy wide excision +/-lymph nodes (?)
Malignant wide excision & lymph nodes (?)

Notes:

  • This classification is still evolving.[1] The preliminary version (above) was presented by Dr. William Faquin at USCAP 2016 in Seattle.[2]
  • The goal is to complete the reporting system by the summer of 2017.

Normal

Depends on the structure that is needled.

Parotid:[3]

  • Acini - small globoid clusters.
    • Separated by adipose tissue.
  • Granular cytoplasm.
  • Nucleus:
  • Low NC ratio cells.

Sticky lymphoid tissue:

  • Irregular globs of tissue with small cells.

Skeletal muscle:

  • Round red staining globs +/-apparent striations.
  • Nuclei more at edges (peripheral).

Images

Salivary gland tumours - summary

Benign

Diagnosis Architecture Cytoplasm Nucleus Main DDx Used to diff. from main DDx Image
Pleomorphic adenoma Fluffy fibromyxoid material & cells and single (plasmacytoid-like) myoepithelial cells  ? Myoepithelial cells - plasmacytoid appearance DDx (?)  ?
Pleomorphic adenoma. (WC)
Warthin tumour (papillary cystadenoma lymphomatosum) Sheets of uniformly spaced oncocytes, lymphocytes, necrotic debris Oncocytes (abundant, granular, eosinophilic tinge), well-defined cell borders Oncocytes have nucleolus Acinic cell carcinoma (AcCC), oncocytoma AcCC: irregular spaced cells, lack well-defined cell borders
Warthin tumour - high mag. (WC)

Malignant

Diagnosis Architecture Cytoplasm Nucleus Main DDx Used to diff. from main DDx Image
Mucoepidermoid carcinoma Clumps of cells Abundant whispy cytoplasm Small oval nucleus, +/-distinct nucleolus Mucocele ? Nuclear atypia
Mucoepidermoid carcinoma. (WC)
Adenoid cystic carcinoma (AdCC) Circular islands of abundant very small cells Scant cytoplasm Small nucleus - may have carrot shape AcCC Basement membrane material - PAS-D+ve[4]
Adenoid cystic carcinoma. (WC)
Acinic cell carcinoma (AcCC) 3-D clusters of small cells Abundant orangeophilic granular cytoplasm Stippled chromatin Warthin tumour AcCC missing lymphocytic background; irreg. spacing of cells
Acinic cell carcinoma. (WC)

Salivary gland

Sialoadenitis

Cytology

Features:

  • Inflammatory cells - lymphocytes, plasma cells - key features.
  • +/-Squamous metaplasia.
  • +/-Necrotic debris.
  • Benign ductal epithelium.

DDx:

  • Squamous carcinoma.
  • Mucoepidermoid carcinoma.

Pleomorphic adenoma

  • Abbreviated PA.

General

  • Common benign tumour.

Cytology

Features (MEC):[5][6]

  1. Myoepithelial cells.
    • Plasmacytoid-like cells.
      • Single cells (very common) or small clumps - oval shape.
  2. Epithelial cells.
  3. Chondromyxoid stroma.
    • Whispy/fluffy groups of spindle cells that overlap (fibromyxoid tissue) - blue-ish.

DDx:

Images

Warthin tumour

  • AKA papillary cystadenoma lymphomatosum.

General

  • Usual smokers.
  • May be bilateral.

Cytology

Features:[7]

  • Oncocytes.
      • Well-defined cell border.
      • Granular cytoplasm.
      • Nucleoli.
    • Oncocytes are often associated with mast cells, i.e. on "top of" oncocytes.
      • Mast cells: very granular dark staining cytoplasm (on smears).
  • Lymphocytes.
  • Necrotic material (cyst contents).

DDx:

  • Acinic cell carcinoma.
    • Spacing of tumour in AcCC is more irregular and appear more crowded.
    • The cell borders in AcCC is less obvious.
  • Oncocytoma.
    • Oncocytoma (vis-a-vis Warthin tumour) has more cells, more cytoplasm, more granularity of cytoplasm, more complex architecture.[3]

Images

Oncocytoma

General

Cytology

Features:

  • Oncocytes.
      • Well-defined cell border.
      • Granular cytoplasm.
      • Nucleoli.

Vis-a-vis Warthin tumour:

  • Oncocytoma has:[3]
    • More cells,
    • More cytoplasm,
    • More granularity of cytoplasm,
    • More complex architecture.

Mucoepidermoid carcinoma

General

  • A challenging FNA diagnosis.[8]

Cytology

Features:

  • Sheets of cells.
  • Cells have a small oval nucleus with nucleolus.
  • Fluffy cytoplasm with a pink tinge (on Pap stain) - key feature.
    • Cytoplasm not seen in 3-D clusters - look for single layer of cells.
    • Cell borders are often distinct.

DDx:

Images

Acinic cell carcinoma

General

  • Uncommon.

Cytology

Features:[10]

  • Abundant granular cytoplasm.
  • Stippled chromatin.
  • +/-Nucleolus.

Notes:

  • Often accompanied by stripped nuclei; may mimic lymphocytes (may lead to confusion with Warthin tumour).
  • Lack:[3]
    • Adipocytes between acini (differentiates from normal).
    • Ductal structures (differentiates from normal).

Memory device:

  • AcCC - lots of "C"s: lots of cytoplasm, carcinoid-like (stippled chromatin, granular cytoplasm).

Image

Adenoid cystic carcinoma

General

Cytology

Features:

  • Solid circular islands that are well-circumscribed.
    • Classically forms cystic structures.
  • Very cellular.
  • Small cells - key feature.
  • Nucleus - large relative to cell (high NC ratio)
    • Often oval/triangular - may be carrot-shaped.
    • +/-Nucleolus. (???)
    • Chromatin NOT stippled.
  • Scant cytoplasm - key feature.

Notes:

  • Memory device: AdCC = lotsa DNA in relation to cell.

Image

Epithelial-myoepithelial carcinoma

Cytology

Features:

  • Single cells/stripped nuclei.
  • 3-dimensional clusters.
  • Two cell population:
    • Dark small cells.
    • Light large cells.

Common

Squamous carcinoma

  • AKA squamous cell carcinoma.

Cytopathology

Features:

  • Mix of spindle cells/epithelioid cells, present in clusters, +/-small number of single cells.
  • Keratinization:
    • Orange/red staining on Pap stain.
      • Poorly differentiated SCC = not orange/red.
    • "Intense" (blue) staining of cells on rapid Romanowsky + pyknotic (small shriveled) nucleus.[11]
  • "Dense" appearing cytoplasm.
    • +/-Laminae (layers)/lines in the cytoplasm.
  • Nuclear features of malignancy (required for diagnosis):
    1. Irregular nuclear membrane, e.g. notches, sharp discontinuities.
    2. Nuclear hyperchromasia - "jet-black" nuclei on Pap stain key feature.
    3. Increased NC ratio.
    4. Variation of nuclear size from cell-to-cell.
    5. Granular chromatin.

Notes:

  1. One should see abnormal squamous cells to call it SCC.
  2. Poorly differentiated SCC may look like adenocarcinoma.

Melanoma

Features:

  • Usually mixed population of:
    • Spindle cells.
      • Often single/detacted cells.
    • Epithelioid cells - usually predominant.
      • Nucleus typically eccentric.
  • Brown granular cytoplasm; usually fine granularity.
  • Large red nucleoli (classic finding).
  • +/-Intranuclear inclusions.
  • +/-Binucleation.

Minimal (for morphologic diagnosis):

  1. Nuclear features of malignancy in epithelioid cells (with an eccentric nucleus) or spindle cells.
  2. Brown granular cytoplasm.

Notes:

  1. IHC stains are needed in many cases (S-100, HMB-45, Melan A).
  2. The classic appearance of melanoma without pigment is closest to adenocarcinoma (which may have red nucleoli, large cells, abundant cytoplasm, occasional binucleation).
    • Differentiating morphologic features: adenocarcinoma - 3-D clusters of cells, no spindle-shaped cells.

Lymph nodes

Normal lymph node

Cytology

  • Mixed population of lymphoid cells.
  • +/-Lymphoglandular bodies.

Image

Non-Hodgkin's lymphoma

Cytology

Features:

  • Population of monomorphous lymphoid cells - usu. ~2x the size of a RBC.
  • Lymphoglandular bodies - blue-grey bodies.
    • Often about 1/2 the size of a RBC.
      • These may be seen in benign tissue.

Note:

Image

Hodgkin's lymphoma

Cytology

Features:

  • Reed-Sternberg cell (diagnostic).
    • Classically binucleated.
    • Huge cell with macronucleus.
    • Each nucleus has a huge macronucleolus.
  • Commonly seen with eosinophils.

Note:

  • RSCs are usually found at the edge of smears.[13]

Images

www:

Cystic lesions of the neck

General

DDx

Lateral:

Medial:

Both:

See also

References

  1. URL: http://www.cytopathology.org/the-milan-system-for-reporting-salivary-gland-cytopathology/. Accessed on: 31 March 2016.
  2. URL: http://www.uscap.org/meetings/detail/2016-annual-meeting/sessions/2334. Accessed on: 13 March 2016.
  3. 3.0 3.1 3.2 3.3 Boerner SL. Patterns and pitfalls in fine needle aspiration of salivary gland. Current Diagnostic Pathology. 9:339-354. 2003. URL (abstract only): http://www.journals.elsevierhealth.com/periodicals/ycdip/article/PIIS0968605303000711/abstract.
  4. Chen SY (November 1976). "Adenoid cystic carcinoma of minor salivary gland. Histochemical and electron microscopic studies of cystlike space". Oral Surg. Oral Med. Oral Pathol. 42 (5): 606–19. PMID 62333.
  5. Thompson, Lester D. R. (2006). Head and Neck Pathology: A Volume in Foundations in Diagnostic Pathology Series (1st ed.). Churchill Livingstone. pp. 295-319. ISBN 978-0443069604.
  6. SM. 13 January 2010.
  7. http://sciencelinks.jp/j-east/article/200123/000020012301A0753392.php
  8. Cohen, MB.; Fisher, PE.; Holly, EA.; Ljung, BM.; Löwhagen, T.; Bottles, K.. "Fine needle aspiration biopsy diagnosis of mucoepidermoid carcinoma. Statistical analysis.". Acta Cytol 34 (1): 43-9. PMID 2296840.
  9. Sidawy, Mark K.; Ali, Syed Z. (2007). Fine Needle Aspiration Cytology: A Volume in Foundations in Diagnostic Pathology (1st ed.). Churchill Livingstone. pp. 25. ISBN 978-0443067310.
  10. SB. 12 January 2010.
  11. GS. 24 February 2010.
  12. 12.0 12.1 URL: http://moon.ouhsc.edu/kfung/jty1/CytoLearn/CytoQuiz/CQ-021-040/CQ-024-M.htm. Accessed on: 9 April 2012.
  13. 13.0 13.1 URL: http://moon.ouhsc.edu/kfung/jty1/CytoLearn/CytoQuiz/CQ-021-040/CQ-026-M.htm. Accessed on: 9 April 2012.