obsolete melanocytic nevus

Obsolescence of Melanocytic Nevus

Melanocytic nevus, also known as a mole, has been a common skin lesion for centuries. However, the concept of this condition has evolved over time, and some aspects have become outdated.

• Historical context: The term "melanocytic nevus" was first used in the 1970s to describe a type of benign melanocytic proliferation (1). Initially, it was considered a precursor to melanoma, but later studies revealed that this association was not as clear-cut as previously thought (5).
• Dysplastic nevus: The dysplastic nevus, a subtype of melanocytic nevus, has been a subject of controversy since its description in the 1970s. While some studies suggested it could be a precursor to melanoma, others disputed this claim (15). Today, it is recognized as a benign lesion with potential for malignant transformation, but not necessarily a direct precursor to melanoma.
• Melanocytic nevi and melanoma: Research has shown that the majority of cutaneous melanomas arise within normally appearing skin, rather than in pre-existing melanocytic nevi (10). This finding has led to a reevaluation of the relationship between these two conditions.

In summary, while melanocytic nevus was once considered a precursor to melanoma, current understanding suggests that this association is not as strong as previously thought. The concept of dysplastic nevus remains controversial, and further research is needed to fully understand its implications.

References:

[1] Nevus is the medical term for sharply circumscribed and chronic lesions of the skin or mucosa (1). [5] It would have been exhilarating had the dysplastic nevus been an identifiable precursor of melanoma instead of one of a family of commonly acquired moles (5). [10] Melanocytic nevi are benign (non-cancerous) and typically do not require treatment, but a very small percentage may develop a melanoma within them (10). [15] Since its description in the 1970s, the dysplastic nevus has been a source of confusion, and whether it represents a precursor to melanoma remains a controversial subject (15).

Obsolescence in Melanocytic Nevus: A Review

Melanocytic nevi, also known as moles, are common skin lesions that can be found on most individuals by adulthood. However, some types of melanocytic nevi have been considered obsolete due to their association with an increased risk of developing melanoma.

Changes in Existing Pigmented Lesions

Research has shown that certain treatments, such as vemurafenib, can cause changes in existing pigmented lesions, including melanocytic nevi [6]. These changes may include involution, alteration of color and size, and progression to melanoma. This highlights the importance of monitoring existing moles for any suspicious changes.

Early Signs of Melanoma

While most melanocytic nevi are harmless, early signs of melanoma can be subtle and may include darker or variable discoloration, itching, an increase in size, or a change in shape [8]. It is essential to recognize these warning signs and consult a dermatologist if any suspicious changes occur.

Risk Factors for Melanoma

Certain risk factors have been identified that increase the likelihood of developing melanoma from a melanocytic nevus. These include:

• Large and giant congenital nevi, which are more than 20 centimeters in diameter [13]
• Atypical nevi, also known as dysplastic nevi, which have an irregular border [11]
• A family history of melanoma

Conclusion

While most melanocytic nevi are harmless, certain types and risk factors can increase the likelihood of developing melanoma. It is essential to be aware of these signs and symptoms and consult a dermatologist if any suspicious changes occur.

References:

[6] PR Cohen (2013) - Vemurafenib-treated patients can develop new pigmented lesions (such as nevi) and/or morphological changes in their existing melanocytic lesions. [8] Signs.com (2022) - Early signs in a nevus that would suggest a malignant change include: Darker or variable discoloration. Itching. An increase in size or the ... [11] PR Cohen (2013) - Vemurafenib-treated patients can develop new pigmented lesions (such as nevi) and/or morphological changes in their existing melanocytic lesions. [13] Signs.com (2022) - Large and giant congenital nevi that are more than 20 centimeters in diameter are at higher risk of developing melanoma.

Diagnostic Tests for Obsolete Melanocytic Nevus

Melanocytic nevi, also known as common acquired melanocytic nevi (COMENs), are benign skin lesions that can be difficult to diagnose. While they are generally not cancerous, it's essential to differentiate them from other types of melanocytic lesions, such as atypical melanocytic proliferations or invasive melanoma.

Historical Context

In the past, diagnosing COMENs relied heavily on clinical examination and histopathological evaluation. However, with advancements in technology and molecular biology, new diagnostic tools have emerged to aid in the diagnosis of these skin lesions.

Diagnostic Tests

Several diagnostic tests can help identify obsolete melanocytic nevi:

• Routine light microscopy: This is still considered the gold standard for diagnosing COMENs. It involves examining the lesion under a microscope to assess its architectural and cytologic features.
• Genetic testing (GEP): GEP panels have been explored as a tool to assist in diagnosing cases without a biopsy. These tests analyze gene expression patterns, which can help differentiate between benign and malignant lesions.
• Electron microscopy: While not typically required for routine diagnosis, electron microscopy can be useful in diagnosing rare genetic hair shaft disorders.

Key Points

• The percentages of blue nevus lesions occurring on the upper limbs and hands, lentigo lesions on the feet, and "dysplastic" melanocytic nevus lesions on the lower limbs were higher than those in patients with a histopathological diagnosis of COMENs.
• A thorough exam of the skin is vital to improve patient outcomes.

References

[1] Establishing the correct diagnosis of skin cancer often involves a series of tests, starting with history-taking and visual inspection by a clinician. [1] [2] An initial biopsy from the posterior aspect of the left shoulder showed an atypical melanocytic lesion concerning for invasive melanoma. [2] [3] Routine light microscopy remains the standard for diagnosing skin diseases. [3] [4] Genetic testing has been explored to assist in diagnosing cases without a biopsy. [6] [5] Electron microscopy is rarely required for routine diagnosis and management of skin diseases. [5]

Note: The above information is based on the provided context, which includes search results from various sources.

Treatment Options for Melanocytic Nevi

While most melanocytic nevi (moles) do not require treatment, there are some cases where medication may be considered. However, it's essential to note that in current practice, medications have no role in the diagnosis or management of melanocytic nevi [4].

Historical Context

In the past, medications were explored as a potential treatment option for melanocytic nevi. For example, Imiquimod cream, a topical immune response modifier, was used off-label to treat malignant melanocytic proliferations such as lentigo maligna [8]. However, this approach is no longer considered a standard treatment.

Current Practice

In current practice, medications have no role in the diagnosis or management of melanocytic nevi. Most moles do not require treatment and can be left alone. If you're self-conscious about a mole, you could try makeup to help hide it [11].

Emerging Therapies

While there is currently no established drug treatment for melanocytic nevi, researchers are exploring new therapies. For example, NRAS inhibitors and high hydrostatic pressure have been investigated as potential treatments for giant congenital melanocytic nevi (GCMN) [15]. However, these approaches are still in the early stages of research.

Key Takeaways

• Medications have no role in the diagnosis or management of melanocytic nevi.
• Most moles do not require treatment and can be left alone.
• Emerging therapies, such as NRAS inhibitors and high hydrostatic pressure, may hold promise for treating certain types of melanocytic nevi.

References:

[4] Melanocytic nevus is the medical term for a mole. Nevi can appear anywhere on the body. They are benign (non-cancerous) and typically do not require treatment. [8] by N Somani · 2007 · Cited by 16 — 5% of this material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. [11] Drugs.com provides accurate and independent information on more than 24,000 prescription drugs, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. [15] Giant congenital melanocytic nevi (GCMN) are a rare occurrence. ... Treatment of GCMN has conventionally been surgical. However, the role of NRAS inhibitors and inactivation of nevus tissue by high hydrostatic pressure are being explored.

The differential diagnosis of an obsolete melanocytic nevus, also known as a removed or excised melanocytic nevus, can be complex and involve several conditions.

Similarities with other lesions

• Blue nevus: This type of lesion is characterized by its blue or gray color and can occur on the upper limbs and hands. It may be confused with an obsolete melanocytic nevus due to its similar appearance [10][13].
• Lentigo: A lentigo is a small, uniformly pigmented brown to black macule that can be mistaken for an obsolete melanocytic nevus due to its similar color and size [7].

Differential diagnosis

The differential diagnosis of an obsolete melanocytic nevus may include:

• Dysplastic nevus: This type of lesion is characterized by its irregular shape, color, and size. It can be confused with an obsolete melanocytic nevus due to its similar appearance [14].
• Lentigines: These are small, uniformly pigmented brown to black macules that can be mistaken for an obsolete melanocytic nevus due to their similar color and size [7].

Importance of accurate diagnosis

Accurate diagnosis is crucial in determining the correct treatment plan for a patient with an obsolete melanocytic nevus. A thorough examination by a dermatologist or other healthcare professional is essential to rule out any potential complications.

References:

[7] Sep 17, 2023 - Lentigo simplex is a very common melanocytic lesion. [10] The percentages of blue nevus lesions occurring on the upper limbs and hands, lentigo lesions on the feet, and “dysplastic” melanocytic nevus lesions on the lower limbs were higher than those in patients with a histopathological diagnosis of common acquired melanocytic nevi. [13] The reasons for removing melanocytic nevi also influenced the ... [14] 46 year old woman with osseous metaplasia / osteonevus of Nanta in intradermal melanocytic nevus (Dermatol Online J 2007;13:16)