Nevus spilus, also known as nevoid lentigo, is a common, benign skin lesion that can appear anywhere on the body. It often first appears during infancy or childhood, though it can develop at any age. This condition is characterized by a light brown or tan patch of skin, which can range in size from 1 cm to 20 cm.
Clinical Features and Characteristics
Nevus spilus typically appears as a well-defined patch of light brown pigmentation, often oval or irregular in shape. Inside the patch, there are numerous darker, smaller spots or macules. The color of the lesion can range from light brown to darker shades, depending on how many pigmented spots are present. These lesions can vary in size from 1 cm to more than 20 cm across and are usually flat, though some may have slightly raised areas.
Nevus spilus usually appears in childhood, but it can also develop in adulthood. It can show up anywhere on the body, although it is most often found on the trunk and limbs. Most of the time, the lesion stays the same over the years, but it’s important to keep an eye on it for any changes in size, shape, or color. These changes may suggest the need for further medical attention.
Differential Diagnosis
While nevus spilus is a benign lesion, its differential diagnosis includes several other pigmented skin lesions, which may present with similar features. These include:
Congenital melanocytic nevi: These are present at birth and are often larger than nevus spilus lesions, with a more uniform pigmentation.
Lentigo: A benign, flat, pigmented spot often associated with sun exposure.
Melanocytic nevi: These typically present as well-defined, raised lesions, differing from the flat, speckled appearance of nevus spilus.
Melanoma: A malignant lesion that may resemble nevus spilus, particularly when there are changes in size, shape, or color, making early detection and monitoring crucial.
Diagnosis
The diagnosis of nevus spilus is primarily made through a clinical examination, based on its characteristic appearance. A thorough history and physical exam are crucial for confirming the diagnosis. Dermatologists may use dermatoscopy to examine the lesion in more detail. Dermoscopy typically shows a uniform background pigmentation with smaller, darker spots, which helps differentiate nevus spilus from other conditions, such as lentigo or melanoma.
If there are concerns about the lesion’s benign nature, or if the nevus changes in size, shape, or color, a biopsy may be performed to rule out any malignancy. However, if the lesion remains stable over time, a biopsy is usually not needed.
Management and Treatment
Since nevus spilus is a benign and typically asymptomatic lesion, no treatment is needed unless there are changes that raise concern. It is important to monitor for morphological changes, such as increased size, changes in color, or irregular borders, as these could indicate a rare risk of malignant transformation.
If a lesion changes or becomes problematic, several treatment options are available:
Excision: If the lesion becomes large, cosmetically concerning, or shows signs of malignancy, surgical excision may be recommended. This helps remove the lesion and provide a definitive diagnosis.
Laser therapy: For cosmetic reasons, laser treatment, such as Q-switched laser, can be used to reduce pigmentation and improve the appearance of the nevus. It is non-invasive and provides a good cosmetic outcome.
Cryotherapy or Electrodesiccation: These treatments are generally avoided for nevus spilus, especially in larger lesions, due to the risk of scarring or skin damage.
In most cases, if the lesion remains stable, observation with regular monitoring is sufficient.
Prognosis and Follow-Up
The prognosis for individuals with nevus spilus is excellent, because it is typically a harmless condition. However, there is a potential for malignant transformation in rare cases. For this reason, it’s important to have regular check-ups, especially if the lesion is large or changing. It’s also helpful to keep track of any changes in the spot’s size, color, or shape on your own. Regular visits to a dermatologist can help catch any issues early and prevent complications.
Conclusion
Nevus spilus is a harmless skin spot that often appears in childhood. It looks like a light brown patch with darker spots on it. While it’s usually not a problem, it’s important to watch for any changes that could suggest it might become more serious. Doctors can usually diagnose it by looking at the spot, and treatment is not needed unless it causes concern about appearance or if it starts changing in a worrying way. In some cases, the spot might be removed with surgery or treated with a laser, but the most important part of care is regular check-ups to monitor any changes.
References
Bolognia, J. L., Schaffer, J. V., & Cerroni, L. (2023). Dermatology (4th ed.). Elsevier.
Gandhi, V. K., & Gupta, S. (2021). Benign pigmented lesions: Diagnosis and management. Indian Journal of Dermatology, 66(2), 104-110.
Kazandjieva, J., Dimitrova, P., & Tsankov, N. (2022). Dermatologic manifestations of benign and malignant skin tumors. Clinics in Dermatology, 40(1), 92-105.
Marghoob, A. A., Kraemer, K. H., & Kopf, A. W. (2022). Pigmented lesions: Diagnosis and management. American Journal of Clinical Dermatology, 23(4), 553-560.
Sullivan, M., Vasily, V., & Fawcett, W. (2022). Laser treatment of pigmented lesions: Advances in technology and outcomes. Lasers in Surgery and Medicine, 54(6), 508-515.
