Clonal seborrheic keratosis

Clonal Seborrheic Keratosis is a common benign skin growth, representing a variant of seborrheic keratosis. It is characterized by the presence of a well-demarcated, slightly elevated, pigmented lesion that typically appears on the trunk, face, or extremities. Unlike the more uniform appearance of classic seborrheic keratosis, clonal seborrheic keratosis exhibits clusters of small, basaloid cells within the lesion, giving it a distinctive histological pattern. This article provides an overview of clonal seborrheic keratosis, including its clinical features, diagnosis, and management.

Clinical Features

Clonal seborrheic keratosis typically presents as a solitary, round to oval, brown to black plaque. The size can vary from a few millimeters to several centimeters in diameter. The surface of the lesion is usually smooth or slightly verrucous, and it may have a "stuck-on" appearance. Patients often report no symptoms, but lesions can become irritated or itchy, especially if located in areas subject to friction.

Diagnosis

The diagnosis of clonal seborrheic keratosis is primarily clinical, based on the lesion's appearance. Dermoscopy can aid in the diagnosis, revealing specific features such as milia-like cysts, comedo-like openings, and a network of fine vessels. However, the definitive diagnosis is made through histopathological examination, which distinguishes clonal seborrheic keratosis from other pigmented lesions by identifying the characteristic clusters of basaloid cells.

Differential Diagnosis

Clonal seborrheic keratosis must be differentiated from other skin lesions, including melanoma, basal cell carcinoma, and actinic keratosis. Melanoma, in particular, can mimic seborrheic keratosis, making histological examination crucial for accurate diagnosis.

Management

Treatment of clonal seborrheic keratosis is generally not necessary unless the lesion is symptomatic or cosmetically concerning. Various methods can be used for removal, including cryotherapy, curettage, laser therapy, or electrosurgery. It is important to monitor the lesion for any changes in size, color, or shape, as these could indicate malignant transformation, although this is extremely rare.

Conclusion

Clonal seborrheic keratosis is a benign skin lesion that is part of the seborrheic keratosis family. While it poses no significant health risk, its resemblance to malignant skin lesions necessitates careful diagnosis and monitoring. Treatment is typically reserved for symptomatic or cosmetically undesirable lesions.