Head and neck cytopathology
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.
Normal
Depends on the structure that is needled.
Parotid:[1]
- Acini - small globoid clusters.
- Separated by adipose tissue.
- Granular cytoplasm.
- Nucleus:
- Dispersed chromatin.
- Indistinct nucleolus.
- Low NC ratio cells.
Sticky lymphoid tissue:
- Irregular globs of tissue with small cells.
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), Warthin tumour intermed 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[2] | 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
Main article: Salivary gland
Pleomorphic adenoma
General:
- Common benign tumour.
- Abbreviated PA.
Cytology
- Myoepithelial cells.
- Plasmacytoid-like cells.
- Single cells (very common) or small clumps - oval shape.
- Plasmacytoid-like cells.
- Epithelial cells.
- Chondromyxoid stroma.
- Whispy/fluffy groups of spindle cells that overlap (fibromyxoid tissue) - blue-ish.
Image:
DDx:
- Adenoid cystic carcinoma.
- Big circular globs (cysts) - common in AdCC.
Warthin tumour
- AKA papillary cystadenoma lymphomatosum.
General
- Usual smokers.
- May be bilateral.
Cytology
Features:[5]
- 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).
Images:
- Warthin tumour high mag (WC).
- Warthin tumour intermed mag (WC).
- Warthin tumour - surgical excision specimen (WC).
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.[1]
Oncocytoma
General
- May be confused with Warthin tumour.
Cytology
Features:
- Oncocytes.
- Well-defined cell border.
- Granular cytoplasm.
- Nucleoli.
Vis-a-vis Warthin tumour:
- Oncocytoma has:[1]
- More cells,
- More cytoplasm,
- More granularity of cytoplasm,
- More complex architecture.
Mucoepidermoid carcinoma
Main article: Mucoepidermoid carcinoma
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.
Images:
- Mucoepidermoid carcinoma (WC).
- Mucoepidermoid carcinoma - very high mag. (WC).
- Mucoepidermoid carcinoma - not a very good image (WC).
Acinic cell carcinoma
Main article: Acinic cell carcinoma
General
- Uncommon.
Cytology
Features:[6]
- Abundant granular cytoplasm.
- Stippled chromatin.
- +/-Nucleolus.
Notes:
- Often accompanied by stripped nuclei; may mimic lymphocytes (may lead to confusion with Warthin tumour).
- Lack:[1]
- Adipocytes between acini (differentiates from normal).
- Ductal structures (differentiates from normal).
Image:
Memory device:
- AcCC - lots of "C"s: lots of cytoplasm, carcinoid-like (stippled chromatin, granular cytoplasm).
Adenoid cystic carcinoma
General
- Usu. distinctive.
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:
Common
Squamous carcinoma
Main article: Squamous cell 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.[7]
- Orange/red staining on Pap stain.
- "Dense" appearing cytoplasm.
- +/-Laminae (layers)/lines in the cytoplasm.
- Nuclear features of malignancy (required for diagnosis):
- Irregular nuclear membrane, e.g. notches, sharp discontinuities.
- Nuclear hyperchromasia - "jet-black" nuclei on Pap stain key feature.
- Increased NC ratio.
- Variation of nuclear size from cell-to-cell.
- Granular chromatin.
Notes:
- One should see abnormal squamous cells to call it SCC.
- Poorly differentiated SCC may look like adenocarcinoma.
Melanoma
Main article: Malignant melanoma
Features:
- Usually mixed population of:
- Spindle cells.
- Often single/detacted cells.
- Epithelioid cells - usually predominant.
- Nucleus typically eccentric.
- Spindle cells.
- Brown granular cytoplasm; usually fine granularity.
- Large red nucleoli (classic finding).
- +/-Intranuclear inclusions.
- +/-Binucleation.
Minimal (for morphologic diagnosis):
- Nuclear features of malignancy in epithelioid cells (with an eccentric nucleus) or spindle cells.
- Brown granular cytoplasm.
Notes:
- IHC stains are needed in many cases (S-100, HMB-45, Melan A).
- 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
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.
- Often about 1/2 the size of a RBC.
Note:
- Small cell lymphomas cannot be diagnosed definitively from cytology.
Image:
Hodgkin's lymphoma
Main article: Hodgkin lymphoma
Features:
- Reed-Sternberg cell (diagnostic).
- Classically binucleated.
- Huge cell with macronucleus.
- Each nucleus has a huge macronucleolus.
- Macronucleolus approximately the size of a RBC.
- Commonly seen with eosinophils.
Note:
- RSCs are usually found at the edge of smears.[9]
Images:
Cystic lesions of the neck
General
- One should never sign-out a cytology specimen as: "branchial cleft cyst" or "thyroglossal duct cyst".
- The proper verbiage is "cystic squamous lesion".
DDx
Lateral:
- Brachial cleft cyst.
- Cystic hygroma.
Medial:
- Thyroglossal duct cyst.
Both:
- Epidermoid cyst.
- Cystic squmaous cell carcinoma.
See also
References
- ↑ 1.0 1.1 1.2 1.3 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.
- ↑ 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.
- ↑ 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.
- ↑ SM. 13 January 2010.
- ↑ http://sciencelinks.jp/j-east/article/200123/000020012301A0753392.php
- ↑ SB. 12 January 2010.
- ↑ GS. 24 February 2010.
- ↑ 8.0 8.1 URL: http://moon.ouhsc.edu/kfung/jty1/CytoLearn/CytoQuiz/CQ-021-040/CQ-024-M.htm. Accessed on: 9 April 2012.
- ↑ 9.0 9.1 URL: http://moon.ouhsc.edu/kfung/jty1/CytoLearn/CytoQuiz/CQ-021-040/CQ-026-M.htm. Accessed on: 9 April 2012.