When A Patient Presents With An Unusual Lesion On The Sole
Actinic keratosis. This condition is more common on sun-exposed areas of the body and rarely occurs on the plantar aspect of the feet. However, this condition may be very similar to Bowen’s disease when it presents on the lower legs. The distinction between the two is a matter of degree (the extent of the lesion) as opposed to differences in individual cells. One will often see marked hyperkeratosis and areas of parakeratosis with loss of the granular layer. A dense inflammatory infiltrate is usually present. The case has been made that actinic keratosis is the earliest manifestation of squamous cell carcinoma and one should regard it as such rather than as a precancerous lesion. Biopsy of the lesion will help confirm the diagnosis.
Superficial basal cell carcinoma (BCC). This variety of BCC appears as scaly patches or papules that are pink to reddish-brown, and often have central clearing. A threadlike border is common. Erosion is less common in superficial BCC than in nodular BCC. Superficial BCC is common on the trunk and has little tendency to become invasive. The papules may mimic Bowen’s disease, psoriasis or eczema, but they are not prone to fluctuate in appearance. Numerous superficial BCCs may indicate arsenic exposure. Biopsy is essential in the diagnosis.
Lichen simplex chronicus (LSC). This occurs on skin regions accessible to chronic rubbing and scratching. Pruritus provokes rubbing that produces clinical lesions but the underlying pathophysiology is unknown. Some skin types are more prone to lichenification. One example is skin that is more susceptible to eczematous conditions (i.e., atopic dermatitis, atopic diathesis). The possible interplay among primary lesions, psychic factors and the intensity of pruritus additively influences the extent and severity of LSC.
Key Insights On Preventing And Treating Bowen’s Disease
Preventative measures include protection of the solar exposed areas of the body with proper clothing and headgear as well as the use of a broad spectrum sunscreen at all times when outside. Early detection of skin lesions with regular evaluations by a physician is highly recommended.
The treatment for Bowen’s disease depends upon the size and location of lesions, the number of lesions to be treated, and the preference of the physician.
Topical therapy with administration of 5-fluorouracil under occlusion reportedly is effective for the treatment of Bowen’s disease. Patients would apply this cytotoxic cream once or twice daily as a 5% cream for one to eight weeks. Patients may also use imiquimod 5% cream, a topical immune response modifier, which they would apply three to five days per week for six to 16 weeks.
Surgical care can include cryotherapy or curettage. In both of these cases, an accurate diagnosis following biopsy is required before treatment begins. Simple excision with conventional margins of 4 mm is the most common and preferred treatment for smaller lesions and those that are not in challenging areas of the body.
Mohs micrographic surgery is an excellent method for larger lesions, recurrent lesions or those in areas where tissue sparing is vital. This technique uses the systematic surgical removal of skin cancer with very small margins of normal tissue and subsequent frozen section pathology examination. This offers the highest cure rate of all treatment modalities. Since one is removing relatively small borders around the lesion, this is considered a tissue sparing procedure.
Whatever the chosen treatment, one can often cure Bowen’s disease. Occasionally, the lesions come back at the same site but physicians can usually treat these again effectively. Following the successful treatment of Bowen’s disease, one should reevaluate the patient every three to six months.
A failure to recognize Bowen’s disease or to perform a lesion biopsy can lead to delayed treatment. A high degree of suspicion is needed in both sun-exposed and non-sun-exposed areas of the skin. One should send all biopsy specimens of suspected skin lesions to a board certified dermatopathologist for further diagnostic evaluation.