B44, salivary gland diseases Flashcards
What are the main causes of salivary gland inflammation? What is the term for that?
Sialoadenitis
- Traumatic –> leads to mucocele
- Bacteria, suppurative
- Viral, non-suppurative
- Autoimmune
- Secondary
Most frequently is in the form of a Mucocele. Blockage or rupture of a duct in the salivary gland, causes saliva to leak into the surrounding tissue, most often causing a unilateral swelling in the lower lip, which fluctuates with meals.
Bacterial is rare, occurs anterior to a blockage of the duct and oral bacteria opportunistically infect. S. aureus and S. viridans.
Viral: Mumps in healthy individuals, also CMV in IC’d
Autoimmune: Sjogren syndrome, Secondary to sarcoidosis .
What is xerostomia? What causes it and some of its consequences?
Xerostomia = dry mouth
Caused by
- Sjogren/Sicca syndrome
- Iatrogenic is the most frequent cause
- side effect of many drugs, antihypertensives, analgesics, diuretics, muscle relaxants
- Radiation therapy
Can cause:
- Dysphagia
- Fissures, ulcers
- Dental caries
- Candidiasis
What are the most frequent benign tumors of the salivary gland?
- Pleomorphic adenoma - by far the most common ~80%
- Warthin tumor - ~10%
- Oncocytoma
- Cystadenoma
- Basal cell adenoma
last 3 are all about 3%
How freqent are salivary gland tumors?
How does malignancy correlate to the size of the salivary gland that the tumor is in?
Uncommon, but not extremely rare. Are about 2% of all tumors.
The smaller the gland, the more malignant.
Parotid gland tumors are usually benign, with about a 20% chance of malignancy.
Submandibular gland tumor are about 50% malignant
Sublingual gland tumors are about 80% malignant.
Describe pleomorphic adenoma,
frequency, histology, major gene change
transformation
Most common parotid tumore, about 60% of all the tumors.
A mixed tumor, containing epithelial and myoepithelial neoplastic cells. Very low mitotic figures and little dysplasia.
Can also form myxoid (mucinous loose connective tissue), cartilage, or bone tissue.
It is encapsulated, but the neoplastic cells penetrate the capsule, and a wide margin of resection is needed during surgery.
It is a slow growing, benign tumor, but surgery is difficult, because it penetrates its capsule so it reoccurs in about 25% and also it can grow around the facial nerve.
PLAG1 transcription factor overexpression. Unclear function but consistent marker.
2% transform in 5 years and 10% transform over 15 years. Becoming Malignant mixed tumors aka carcinoma ex peomorphic adenoma. These are very aggressive with 50% 5yrS
Describe Warthin tumor
Occur only in the parotid gland
Well demarcated, encapsulated tumor, 2nd most common benign tumor, ~10% of all parotid tumors.
Contains cystic spaces surrounded by double layered epithelium of cuboidal/columnar cells, often called oncocytic cells. Which simply means cells that contain a very high number of mitochondria.
Mucin filled cystic spaces
Contains abundant lymphocytes and germinal centers
Can occur bilateral or multifocal in about 10%
Much more common in Men and Smokers.
Benign, very very rarely transforms, and does not reoccur.
What are the most frequent malignant tumors of the salivary gland?
- Mucoepidermoid carcinoma
- Adenoid cystic carcinoma
- Acinic cell carcinoma
- Adenocarcinoma ex pleomorphic adenoma, malignant mixed tumor
- B-cell non-hodgkin lymphomas
Describe Mucoepidermoid Carcinoma
The most common malignant tumor of the salivary glands.
Occurs most commonly in the parotid gland, but makes up a larger fraction of the tumors in the smaller salivary glands
No capsule, infiltrates locally.
Has cell types ranging from epidermoid, to mucinous, to intermediate cells in between. Can be stained with mucicarmine.
Cells form cords, sheets, or cysts, lined by these neoplastic cells.
Cells can be well or poorly differentiated, and the tumor is graded low, mid, or high-grade, based on the degree of anaplasia.
MAML2 gene mutations are very common, part of the Notch singaling pathway.
15% of low grade tumors metastasize and 5yrS is above 90%
30% of high grade tumors metastasize, and 5yrS is about 50%
Describe Adenoid Cystic Carcinoma
2nd most common malignant salivary gland tumor.
Most common tumor of the small salivary glands. Forms solid cords of cells with a cribriform pattern of small tubules of mucinous secretions.
Cells have large nuclei and not much cytoplasm, arranged in groups/cords.
Very locally invasive, especially in the perineural spaces around nerves. These infiltrations can cause pain.
Grows slowly, but can metastasize hematogenously before regional lymph invasion occurs.
About 50% of them metastasize even if the primary tumor is resected, and can reappear years later at distant sites.
What is the most common type of lymphoma found in the parotid gland?
MALT lymphoma, marginal zone lymphoma.
Burkitt lymphoma is of the ‘jaw’ and not the salivary glands.
