Difference between revisions of "Salivary glands"
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# Sublingual: | # Sublingual: | ||
#*Mucinous glands. | #*Mucinous glands. | ||
How to remember: Sub'''m'''andibular = '''m'''ixed. | |||
Images: | Images: |
Revision as of 17:34, 23 June 2010
The salivary glands help digest food. ENT surgeons take 'em out and want you to diagnose 'em. Cytopathology of the salivary glands is covered in the Head and neck cytopathology article.
Normal
Types of salivary glands
Types of glands:[1]
- Serrous - eosinophilic cytoplasmic granules, acinar arrangement - vaguely resembles the acinar morphology of the pancreas.
- Mucinous - light eosinophilic staining.
Identifying the glands
The three main glands:
- Parotid:
- Serous glands - lower viscosity, acini (lobules).[2]
- Most tumours in this gland are benign.
- Submandibular:
- Serous and mucinous glands.
- Sublingual:
- Mucinous glands.
How to remember: Submandibular = mixed.
Images:
Memory device:
- The parotid gland vaguely resembles the pancreas.
Overview
Benign tumours
Tabular form - adapted from Thompson[3]
Architecture | Morphology | Cell borders | Cytoplasm | Nucleus | DDx | Other | |
Pleomorphic adenoma | var. | mixed pop.; must include: (1) myoepithelium, (2) epithelium, (3) chondromyxoid stroma | var. | var. | (1) plasmacytoid | adenoid cystic c. | occ. encapsulated, mixed pop. of glandular, myoepithelial and mesenchymal cells |
Warthin tumour | papillary, bilayer |
cuboid (basal), columnar (apical) | clearly seen | eosinophilic, abundant | unremarkable | sebaceous lymphadenoma | AKA papillary cystadenoma lymphomatosum |
Basal cell adenoma | var., islands surrounded by hyaline bands |
basaloid | subtle | scant, hyperchromatic |
granular | basal cell adenoca | - |
Canalicular adenoma | chains of cells | cuboid or columnar | subtle | scant, hyperchromatic |
granular | basal cell adenoma | - |
Sialoblastoma | var., islands surrounded by loose fibrous stroma |
basaloid | subtle | scant, hyperch. | granular | basal cell adenoca | - |
Malignant tumours
Tabular form - adapted from Thompson[4]
Architecture | Morphology | Cell borders | Cytoplasm | Nucleus | DDx | Other | |
Mucoepidermoid carcinoma | cystic & solid | epithelioid | distinct | fuffy, clear, abundant |
nuclei sm. | ? | ? |
Acinic cell adenocarcinoma (AcCC) | acinar (islands) | epithelioid | clear | granular, generous | stipled, +/-occ. nucleoli | ? | ? |
Adenoid cystic carcinoma (AdCC) | pseudocysts, cribriform, solid, hyaline stroma |
epithelioid | subtle | scant, hyperchromatic |
small "carrot-shaped" |
? | ? |
Salivary duct carcinoma | glandular, cribriform | columnar | subtle/clear | hyperchromatic | columnar | metastatic breast ca | similar to ductal breast carcinoma |
Polymorphous low-grade adenocarcinoma | variable, often small nests, may be targetoid |
epithelioid | indistinct | eosinophilic | ovoid & small with small nucleoli |
? | minor salivary gland tumour, often in palate, cytologically monotonous |
DDx by site
Palate:
- Polymorphous low-grade adenocarcinoma.
- Adenoid cystic carcinoma.
- Pleomorphic adenoma.
Benign
Mucocele
- Mucous.
Pleomorphic adenoma
Epidemiology
Features:[5]
- Very common - approx. 60% of parotid gland tumours
Histology
Features:[6]
- Proliferation of myoepithelium and epithelium in mesenchymal stroma.
- Mesenchymal stroma - key feature.
- May be any of following: myxoid, mucochondroid, hyalinized, osseous, fatty.
- Look for, i.e. rule-out, poorly differentiated carcinoma: carcinoma ex pleomorphic adenoma.
IHC: S-100+, SMA+, GFAP+.
Basal cell adenoma
- Basophilic cells.
- Nests.
Canalicular adenoma
- Channels.
Papillary cystadeoma lymphomatosum
- AKA Warthin tumour.
- Papillae.
Microscopy
- Papillae (nipple-shaped structures) with a two rows of pink (eosinophilic) epithelial cells (with cuboidal basal cells and columnar luminal cells) -- key feature.
- Fibrous capsule - pink & homogenous on H&E.
- Cystic space.
- Lymphoid stroma.
DDx
- Lymphoepithelial cyst.
- Cyst within a lymph node.
Sebaceous adenoma
- Benign counterpart of sebaceous carcinoma.
Oncocytoma
- Like oncocytomas elsewhere.
- Eosinophilic cytoplasm (H&E) - due to increased number of mitochrondria.
Malignant
Approach:
- Differentiate -- luminal vs. myoepithelial vs. basal.
Mucoepidermoid carcinoma
General:
- Most common malignant neoplasm of salivary gland.
Features:
- Abundant fluffy cytoplasm - with large mucin vacuole.
- Nucleus distorted by mucin vacuole.
Images:
Acinic cell adenocarcinoma
- Abbreviated AcCC.
- Common malignant neoplasm of salivary gland.
Features:
- Psammoma bodies(?).
- Abundant cytoplasm.
- Stipled chromatin.
- Acinar architecture (islands of cells).
Memory device:
- AcCC - lots of "C"s - chromatin stipled, cytoplasm generous.
Adenoid cystic carcinoma
- Common malignant neoplasm of salivary gland.
- AKA cylindroma.[7]
- Should not be confused with dermal cylindroma (a benign skin tumour).
Features:
- Cribriform architecture.
- Scant cytoplasm.
- Carrot-shaped nucleus.
- Hyaline stroma.
Images: Adenoid cystic carcinoma - Mod. Pathol.
Memory device:
- AdCC - mostly DNA (scant cytoplasm), distinct nucleus (carrot-shaped).
Salivary duct carcinoma
Needs work.
- Malignant counterpart of salivary duct adenoma.
Polymorphous low-grade adenocarcinoma
- Classically found in the palate.
- Tumour of the minor salivary glands.
Microscopy
- Cytologically monotonous (uniform) with variable architecture - key feature.
- Architecture: often small nests, may be targetoid.
- Nucleus: ovoid & small with small nucleoli.
- Indistinct cell borders.
- Eosinophilic cytoplasm.
DDx
- Pleomorphic adenoma.
- Adenoid cystic carcinoma.
Carcinoma ex pleomorphic adenoma
- Malignant transformation of pleomorphic adenoma.
- Rare.
- May be subtle.
Microscopy
- Nests of cells, may from glands, single cells. (???)
Note:
- Adenocarcinoma-like.
Sebaceous carcinoma
- Arises from sebaceous glands
- Sebaceous glands are serous glands and clear on H&E.
See also
References
- ↑ http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Oral/oral.htm#LABSALIVA
- ↑ http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Epithelia/Epithel.htm
- ↑ HNP PP.295-319.
- ↑ HNP PP.325-357.
- ↑ HANP P.295.
- ↑ HANP P.295.
- ↑ Chest. May 1957. Vol. 31. No. 5. PP. 493-511. http://www.chestjournal.org/content/31/5/493.abstract