Oral Pathology #8 part 1 - Mohammad Abukar

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Oral Pathology / Lec #8 / Dr. Faleh Sawair

This is the first part of lecture #8 (of the 9th week).. it talks exclusively about the Sjogren's syndrome completing the issue we start discussing before Eid. The second part will be about salivary glands tumors

Patients with Sjogren's syndrome may also have other medical problems as the disease affects other exocrine glands than lacrimal and salivary glands. Here are some of these problems:
Severe tiredness (The patient may sleep up to 15-20 hours a day!), arthritis, xeroderma (dryness of skin), and dryness in the whole respiratory system (nasal dryness and also in other mucus membranes having exocrine glands the whole system will be prone to infections and inflammations e.g.: sinusitis, tracheitis), dysphagia, atrophic gastritis, pancreatitis, skin purpura, anemia, leucopenia, thrombocytopenia (If you asked for a blood film you will notice the hematological abnormalities), About 15-20% of the patients have enlargement of the salivary glands (e.g. parotid gland).
The differential diagnosis of salivary gland enlargement associated with Sjogren's syndrome (three possible diagnoses):
1- Ascending sialadenitis as a consequence of xerostomia. (infection).
2- Inflammation by the syndrome itself.
3- Tumor (Sjogren patients may be prone to tumors, so the swelling may be a tumor, mainly lymphoma)
Histologically:
You see lymphocytic infiltrate (The syndrome is autoimmune, cell-mediated disorder. Immunity attacks salivary glands and other exocrine glands).
The infiltrate is mainly of T-lymphocytes that start around the intralobular ducts (the small ducts that are inside the lobules of the salivary gland) then it spreads and makes destruction of the acini of the glandular tissue to end up with acinar atrophy. So, in the inflamed area you will not see any acini, you will only see lymphocytes.
As for the ducts around which the inflammation started, proliferation of the epithelial and myoepithelial cells take place. This proliferation will form islands of epithelium and myoepithelial cells within a sea of lymphocytes and this is called epimyoepithelial islands (it is formed from epithelial and myoepithelial cells).
Looking at the cells, some have clear cytoplasm and these are the myoepithelial cells while the others are epithelial cells.
This histopathological appearance is characteristic of Sjogren syndrome and is seen in major glands (e.g. parotid).
Normally, interlobular septa (i.e. fibrous connective tissue septa separating the salivary glands into lobules) exist. Lymphocytes do NOT penetrate these septa or the capsule and this is how we differentiate it from lymphoma as it remains localized inside the gland. if it penetrated the capsule then you are talking about a tumor not about Sjogren's syndrome.
How to confirm the diagnosis?
The most important features are dry mouth and eyes. To confirm the diagnosis you have to ensure that the person has a reduced salivary flow.
You have to measure salivation even if the patient complained of mouth dryness because his complaint is subjective and he may have a normal flow. To be objective, we measure the salivation and ensure.
Sialometry test is done to measure the amount of saliva. We measure the mixed unstimulated salivary flow rate. (unstimulated = without chewing anything). The test is done for five minutes as a graduated tube is used and a funnel is put on it to collect saliva for 5 minutes. If the saliva measured was less than 0.1 ml/min., then the patient has xerostomia as the normal unstimulated salivary flow rate is 0.5 ml/min. or maybe more.
To confirm that the patient has xerostamia, Schirmer's test is done by the ophthalmologist by putting something like a filter paper in the inner canthus of the eye (i.e. where the eyelids meet) and wait for wetting of the paper. Wetting is normally more than 5 mm's per 5 minutes. If less than 5 mm then the patient has xerostamia.

Schirmer's test
To confirm our results, we should also do a salivary gland biopsy because dryness may be caused by drugs or other things so we take biopsy to ensure about the existence of pathology in the salivary gland. The biopsy is NOT taken from major glands (e.g. parotid) because of complications such as scar, trauma to the facial nerve, fistula, damage to the gland. So, you go to the minor glands which are smaller and easier and the surgery will be a minor one. You may take the biopsy from the lower lip.. you cut the epithelium and see the underlying submucosa.. take 5 lobules from the minor salivary gland then it is sent to the pathology lab in formalin and there we should look for the histopathological feature..
In histopathology we should not expect to see the same features of a histopathological section in a major salivary gland (epimyoepithelial islands)


So.. What is the thing that is suggestive of Sjogren's syndrome in the minor salivary glands?
Look at the duct, We should see a focus (50+ T-cells) of lymphocytes around the duct. To confirm the diagnoses we should have two or more foci in 4 mm2. so bring a tissue from minor salivary gland which is 2*2 mm in dimensions and if you found more than 2 foci then this is confirmative of Sjogren's syndrome.
A finding of scattered inflammation (ductal dilatation (damage) and fibrosis) does not support the diagnosis of Sjogren because the inflammation may be caused other conditions such as chronic sialadenitis.
To confirm ductal dilatation do sialography. Sialography is injecting a radiopaque material in the duct of the gland then you take a radiograph and you will see snow-storm (also called cherry blossom) that is suggestive of Sjogren syndrome because we have sialectasis (dilatation of the glands because of inflammation and destruction)
Another a bit expensive investigation can be made which is the salivary scintiscanning by injecting a radioactive material ([99Tm] pertechnetate = Technetium-99m pertechnetate) in the person. The radiopaque material goes to the glands such as the salivary glands and there it will be uptaken only if the gland is active (normal).
In Sjogren syndrome no uptake will take place in the salivary glands so you will see a whitish colour as there will be no uptake in parotid, submandibular or sublingual glands.
My comment: (the normal colour that indicates uptake is blackish.. see the pic. below.. number 1 for example is normal.. if itwas clear like #3 then it is not normal
..
So, a negative test means that there is a damaged gland suggestive of Sjogren.




Sjogren is auto-immune mainly by cell mediated immunity BUT also auto-antibodies are found in these patients (So the patient will have both cell-mediated and antibody-mediated immunity) but what makes destruction is the cell-mediated immunity.
So, another investigation that may be done for these patients is to check for autoantibodies
These patients have a lot of autoantibodies. Thus, it is not known what Sjogren's syndrome precisely is whether it is caused by cell-mediated or autoantibody immunity because both are found. Anyhow, the destruction is mainly by the cell-mediated immunity.
It is also not known what the antigen that is responsible for the autoimmunity is because the patients have many autoantibodies  so the mechanism of Sjogren syndrome is not clearly understood.
The antibodies that you ask for in a serology test are: ANA, SS-A, SS-B and RF
ANA (antinuclear antibodies): the most famous of them are SS-A and SS-B..
SS-B is more specific for Sjogren syndrome while SS-A may be found in other auto-immune diseases..
RF (Rheumatoid factor) may be positive in a large group of these patients. RF is seen in Rheumatoid arthritis while ANA is seen in lupus.
* Positive RF doesn't mean that the person has Rheumatoid arthritis.
* Thus, it is not necessary for a patient with dry mouth and eyes with positive RF to have a secondary Sjogren.
What is the difference between primary and secondary Sjorgen?
Primary : Dry eyes and mouth and that's it.
Secondary: Dry eyes and mouth along with a connective tissue disease (rheumatoid arthritis or systemic lupus).
Does a positive rheumatoid factor mean that Sjorgen is secondary?
No, we don't call it secondary unless the patient has the features of rheumatoid arthritis (rheumatoid factor is not exclusive for rheumatoid arthritis, it can be found in other autoimmune diseases).
Positive RF is suggestive for Sjogren, if there are clinical features of rheumatoid arthritis we call it secondary, if not we call it primary.
In serology you will notice increased ESR (erythrocyte sedimentation rate) which is
non-specific and it just means that there is a chronic inflammation in the body.
In serology hypergammaglobulinemia exists as well (increased autoantibodies means increased immunoglobulins in the blood in general).


Etiology:
Unknown
Possible genetic susceptibility .. but what is the trigger??
It is not known but scientists think that it may be an infection whether viral or bacterial but mainly viruses are incriminated in causing this autoimmunity that was originally formed against the virus but ultimately damaged the exocrine glands.
Complications:
B-cell malignant lymphoma in the glands (parotid or other glands).. Sjogren patients are at 40-fold increased risk to develop this malignancy.










By: Mohammad M. Abukar