ORAL MEDICINE | PIGMENTED lesions differential diagnoses | UK undergraduate dentistry

Summary

In this video, we explore differential diagnoses for pigmented lesions in the mouth, focusing on blue or black patches that are often non-painful. The video covers three main categories: lesions from external agents like amalgam tattoos, increased melanin production due to smoking or certain medications, and increased numbers of melanocytes, including melanocytic nevi and melanoma. Key causes such as Addison's disease and oral melonic macules are also discussed, emphasizing the importance of biopsy for uncertain diagnoses. The video highlights the need for careful diagnosis, management, and sometimes medical treatment, depending on the condition.

Takeaways

• 😀 Pigmented lesions in the mouth are typically blue or black patches that are usually painless and can appear as solitary or multiple.
• 😀 Oral pigmentation can be a sign of neoplasia, so a biopsy should be performed if there's uncertainty about the diagnosis or suspicion of malignancy.
• 😀 The causes of oral pigmented lesions can be grouped into three categories: external agents, increased melanin production, and increased melanin-producing cells.
• 😀 Amalgam tattoos are the most common cause of intraoral pigmentation, caused by amalgam particles being implanted into the soft tissues during procedures like restorations or extractions.
• 😀 Smoking can increase melanin production in the mouth, leading to diffuse pigmentation that varies in intensity depending on the amount of tobacco use.
• 😀 Certain drugs, such as anti-malarial drugs and contraceptive pills, can stimulate melanocytes to produce more melanin, leading to pigmentation.
• 😀 Oral melonic macules, also known as 'oral freckles,' are idiopathic pigmented lesions with no risk of malignant transformation.
• 😀 Addison's disease, a condition causing adrenal insufficiency, can lead to hyperpigmentation of the mouth due to increased ACTH levels stimulating melanocytes.
• 😀 Physiological pigmentation during pregnancy, known as melasma, can also result in oral pigmentation, along with other types of pigmentation like Hoyt's Jager syndrome.
• 😀 Pigmented lesions caused by long-term inflammatory mucosal disorders, such as oral lichen planus or pemphigus, can lead to post-inflammatory melanin incontinence.
• 😀 Melanocytic nevi (benign proliferation of melanocytes) and melanoma (malignant melanocytes) are the key conditions to consider when diagnosing oral pigmented lesions, with melanoma being rare but serious.

Q & A

What are oral pigmented lesions, and how do they typically present?

Oral pigmented lesions are blue or black patches in the mouth that are rarely painful. They can appear as solitary or multiple lesions and might require a biopsy if there's any uncertainty about the diagnosis or suspicion of malignancy.

What is one of the main causes of oral pigmentation?

One of the main causes of oral pigmentation is the deposition of external agents, such as amalgam tattoos, which occur when amalgam particles are implanted into the soft tissues of the mouth during dental procedures like restorations or extractions.

What is an amalgam tattoo, and how does it occur?

An amalgam tattoo is a form of oral pigmentation that appears as a gray or black macule in the mouth. It happens due to the traumatic implantation of amalgam particles into the soft tissues, typically during dental procedures such as restoration placement or tooth extraction.

How can smoking lead to oral pigmentation?

Smoking can stimulate melanocytes to produce more melanin, leading to diffuse oral pigmentation. The intensity of the pigmentation varies depending on the amount of tobacco use, and cessation of smoking is the primary recommendation for management.

What role do drugs play in oral pigmentation?

Certain drugs, such as anti-malarial medications and contraceptive pills, can stimulate melanocytes to produce more melanin, resulting in oral pigmentation. The diagnosis is typically based on the patient's history, and stopping the medication may resolve the pigmentation.

What is an oral melanotic macule?

An oral melanotic macule is a benign increase in melanin deposition in the mouth, akin to a freckle on the skin. It is idiopathic, meaning the cause is unknown, and it does not carry a risk of malignant transformation.

How does Addison's disease lead to oral pigmentation?

In Addison's disease, the adrenal glands do not produce enough cortisol, which leads to an increase in adrenocorticotropic hormone (ACTH). This stimulates melanocytes to produce more melanin, resulting in hyperpigmentation of the skin and oral mucosa.

What is physiological pigmentation of pregnancy, and how does it affect the mouth?

Physiological pigmentation of pregnancy, also known as melasma, can cause increased pigmentation in the oral mucosa. This type of pigmentation typically resolves after childbirth and doesn't require treatment.

What is the significance of Hoyt's Jager syndrome in relation to oral pigmentation?

Hoyt's Jager syndrome is a genetically inherited condition characterized by numerous freckles around the mouth, as well as intraoral pigmentation. It is important to diagnose this syndrome due to the associated genetic risk for bowel cancer.

How can post-inflammatory melanin incontinence affect oral pigmentation?

Post-inflammatory melanin incontinence occurs when long-standing inflammatory mucosal disorders, such as oral lichen planus or pemphigus, cause pigmentation in the mucosal tissues of the mouth.