Pimented lesions Flashcards
What is the most common oral mucosal lesion of melanocytic origin?
Melanotic macule.
How does a melanotic macule present?
Small, solitary, well-circumscribed, uniformly pigmented.
What are the most common sites for a melanotic macule?
Lower lip, gingiva, and palate but any mucosal site can be affected
What are the differential diagnoses for a melanotic macule? (3)
- Malignant melanoma,
- melanocytic nevus (blue),
- amalgam tattoo.
Is smoker’s melanosis considered pre-neoplastic?
No, it is not considered pre-neoplastic.
What might cause smoker’s melanosis?
unknown aetiology but Thought to be a protective mucosal response to heat or irritants.
How does smoker’s melanosis present?
Diffuse, patchy, irregular pigmentation of anterior facial maxillary and mandibular gingivae.
What are the two types of drug-induced melanosis?
Mucosa appears pigmented (not true pigmentation) and true pigmentation through melanin induction.
What drugs are commonly associated with drug-induced melanosis?
- Tetracycline
- antimalarials (chloroquine, chlorpromazine)
- oral contraceptives.
What does drug-induced melanosis look like
diffuse but localised to one mucosal region or multifocal
What is malignant melanoma?
Cancer arising from malignant melanocytes - most deadly primary skin cancer
What is the prognosis for malignant melanoma in mucosal sites?
Poorer prognosis than in the skin.
typical demographic of malignant melanoma
Typically occur over age 50, highest incidence in Japanese
where does malignant melanoma most commonly affect
Most commonly affects hard palate and maxillary gingivae
What is the typical presentation of malignant melanoma?
- Macule, plaque or mass
- Well-circumscribed or irregular
- Focally or diffusely pigmented, can even lack pigment
- Non-specific: ulceration, pain, paraesthesia/anaesthesia, tooth mobility or spontaneous exfoliation, root resorption, bone loss
What is hypoadrenocorticism / Addison’s disease?
Potentially life-threatening disease due to adrenal destruction or impairment caused by trauma, autoimmune diseases, infectious agents, neoplasia, genetics, certain medications and iatrogenic causes
how does hypoadrenocorticism / Addison’s disease occur?
- Corticosteroid levels decrease → anterior pituitary gland stimulated to increase synthesis of
- ACTH → ACTH acts on adrenal cortex to stimulate corticosteroid production → negative feedback look from pituitary to slow ACTH production
- If low corticosteroid levels persist, there is persistent ACTH production
What is one of the earliest signs of hypoadrenocorticism / Addison’s disease?
Diffuse mucocutaneous pigmentation on multiple surfaces.
What are some associated features of Addison’s disease?
Hypotension, easy bruising, fatigue, mood swings, weakness.
What causes Cushing disease?
Caused by primary activating pituitary pathology caused by prolonged exposure to high concentrations of endogenous or exogenous corticosteroids
What is one of the earliest signs of Cushing disease?
Diffuse mucocutaneous pigmentation.
What are some associated features of Cushing disease?
Weight gain, hypertension, diabetes, osteoporosis, dyslipidaemia, moon face.
What is Peutz-Jehgers syndrome
Rare genetic disease in tumour suppressor gene
What characterises Peutz-Jeghers syndrome?
Intestinal polyposis and increased susceptibility to cancer.
