Candidates always perform better on the vignettes when presented with lesions if they begin with a description of things that they can clearly observe. For example, if presented with a lesion, first describe the size and the configuration. Attempt to classify the lesion as a a macule, a papule, a plaque, a vesicle, a bullae, an erosion, an ulcer or a nodule.
Describe the lesion’s surface texture. Is it smooth, papillary, the ruckus, fissured, scaly, or crusty? Describe the color. Is it normal like the surrounding tissue, red, whitish, yellow, black or dark, or any other colors?
Describe the consistency, however you can only do this after asking the examiners. It is fair to ask if a lesion is soft, firm, indurated, or hard. You should also ask if the lesion is movable. these factors will help you in formulating your differential diagnosis.
Finally, comment on the distribution. Is it a single lesion or are there multiple lesions. Some entities may appear scattered throughout the mouth.
If shown any radiographs, you should comment on the following observations.
- Well circumscribed- usually slow growing lesions
- Poorly circumscribed- rapidly growing or infiltrating lesions
- Relationship to teeth
- Tooth vitality- Has the lesion affected the vitality of any adjacent teeth?
- Association with unerupted teeth
- Displacement of teeth
- Root resorption
First and foremost, attempt to orient yourself with respect to the sections you are shown. Can you see the surface epithelium? If so, locate any layers of keratinization followed by locating the basement membrane. Typically, the epithelial cells between those layers should be roughly of similar size with normal evidence of mitosis near the basement membrane. Rete ridges and surface contour should also appear normal. Any deviation should be pointed out to the examiners. Particularly look for any cells that are irregularly shaped or larger than normal and note atypical mitotic figures above the basal layer with loss of normal stratification. Those findings could hint at dysplastic changes.
Examine below the basement membrane. Normally this area is populated with connective tissue of which collagen would be the main component. Fibroblasts should be scattered throughout. Take special note of inflammatory infiltrating cells such as lymphocytes, plasma cells, macrophages, neutrophils, and giant cells. Is there hard tissue in the slide? Is there any separation of tissue types near the basement membrane? Point all these findings out to the examiners. It is important that you show basic competency when viewing histology slides. If you cannot identify normal features from abnormal features this can be a problem for you. Practice until you can do this. If you can at least identify what is supposed to be there and what is unusual in the slides, most examiners will give some credit for that, knowing that absolute interpretation at times is subjective.
In practicing these vignettes, put yourself into “exam mode.” Time each one. You have 10 minutes. Have a notepad nearby where you can jot down findings and possibilities for your differential diagnoses. This is how you will get the most out of the section.
Keep in mind, some of the content is subjective. For example a decision of where to biopsy an lesion and how deep one should go. These are things where clinicians have much latitude. At the end of each vignette, the comment section is open for discussion.