OSCE Book - Oral pathology Flashcards
Mrs other has presented with a 6-week history of painless swelling on the right buccal mucosa, as shown in photo. She is otherwise fit and well. She is a non-smoker and consumes 8 units of alcohol a week.
Patient details
Name - Mrs Ann Other
DOB - 1/1/1964
Address - 1232 cromwell road anytown, AB12CD
CHI - 010119641234
You decide to take an excisional biopsy of the lesion. With the help of the patient identification label, the clinical history and the photograph above, complete the pathology request form.
The photo above is from a biopsy of a multi-locular radiolucent lesion at the angle of the mandible.
A - Identify and label on the photo each of the following features
- Cyst wall
- Epithelial lining
- Erthrocytes
- Fibroblasts
- Surface corrugation
- Layer of parakeratinisation
- Basal palisading
- Seperation of the epithelium from the corium
B - What is the diagnosis
B - Odontogenic keratocyst
Another photo in book step 3 - excess antibody is washed off. Step 4 - Fluorescent labelled tissue viewed under UV microscopy
A - The test is direct immunofluorescence
B - In immune mediated vesiculobullous disorders, autoantibodies bind to antigenic sites, either on the epithelial cell surface or within the basement membrane zone, as in the example. The biopsy should be taken from para-lesional tissue as an intact epithelial - connective tissue interface is required. The tissue should be submitted fresh because formalin fixation destroys the antigenic sites
C - The stages involved in direct immunofluorscence are as follows
- Antibodies bound to a fluroscent marker are applied to the tissue section on the slide
- These antibodies recognise the autoantibodies already bound in the tissue.
- The section is then washed and any bound fluorescent antibodies are viewed with flurescent microscope
- The distrubution of the fluorescent antibodies is equivalent to the distrubution of the autoantibodies.
D - In this example the antibody is distrubuted in a linear fashion alinf the basement membrane zone. Therefore, the likely diagnosis is mucous membrane pemphigoid.
Excisional biopsy lower lip, painless swelling.
A - Match the numbered labels with the following structures
- Cyst lumen
- Surface epithelium
- Dialted salivary gland
- Minor mucous gland
B - What is the predominant cell type in the area labelled ‘A’
C - What is your diagnosis and what treatment would you suggest for this patient.
A
1. Surface epithelium
2. Cyst lumen
3. Minor mucous glands
4. Dilated salivary duct
B
- In this example, the cyst lumen is not lined with epithelium and the predominant cell type at the periphery of the cyst is the foamy macrophage
C
- This is a mucus extravasation cyst (extravasation mucocoele). It is usually treated by excising the lesion and assocaited minor salivary gland. It could also be treated with cyrotherapy.
A - The cells labelled as A are osteoclast like giant cells
B - The pigment in the area labelled ‘b’ is haemosiderin. Note the prominent vascular stroma and the dense population of erthrocytes in the background.
C - This is giant cell lesion and therefore the differiential diagnosis will include
- Central giant cell granuloma
- Brown tumour of hyperparathyroidism
- Cherubism
- Aneurysmal bone cyst
- Other giant cell lesions
D - To reach a definative diagnosis, more information would be required, including:
- The age, sex and ethic background of the patient
- The distrubution of the lesion
- The radiological appearance
- Results of biochemical investigation
A - in pic
B - in pic
C
- What stain is used for figure d?
- What structures are highlighted by the arrows?
- Why are these not visible in figure c?
D - What other intr-oral sites does this condition commonly effect?
E - What important possible sequalae of this condition do you need to consider when planning its management?
A - This is a case of chronic hyperplastic candidosis. The abnormality on low and medium power views is the loss of filiform papillae, which should be visible on normal dorsal epithelium. This gives the clinical appearance of a smooth patch. A further abnormality consists of the elongated rete processses. These two features should raise the suspicion of candidosis even in low and medium views
B - The arrows are pointing to polymorphonuclear leucocytes (neutrophils) with typical multilobed nuclei. Neutrophil nuceli are about half the size of keratinocyte nuclei. Their presence in the superfical spinous layer together with irregular surface further raises the suspicion of candida infection.
C - The stain is periodic acid - Schiff (PAS), which stains glycogen, polysaccharides, mucin, mucoprotein and glycoproteins magenta. The structures highlighted are fungal hyphae, whose walls are high in polysaccharides. These are not detected by standard haematoxylin and eosin staining.
D - Chronic hyperplastic candidosis affects the following oral sites in decreasing order of frequency: the buccal commissures, cheeks, palate and tongue.
E - Up to 15% of chronic hyperpastic candida infections may progress to epithelial dysplasia. Furthermore, epithelial dysplasia associated with fungal infection significantly worsens over time in comparison with non-infected epithelial dysplasia. This underscores the importance of close monitoring of recalcitrant lesions that do not resolve after appropriate anti-fungal therapy.
