				Using the search form

If you prefer to view this article in PDF form, click here.

Joe R. Monroe, PA-C, MPAS, DEPARTMENT EDITOR

Melanoma scare prompts this patient to take a new look at an old lesion

Joe R. Monroe, PA-C, MPAS

The author practices in the dermatology department of the Warren Clinic, Tulsa, Okla, and is the founder and president of the Society of Dermatology Physician Assistants. He has indicated no relationships to disclose relating to the content of this article.

A 58-year-old man presents to the dermatology department with a lesion on his right anterior shoulder. The lesion had been growing slowly but steadily for 20 years and had reached the point where activities such as bathing, dressing, and normal movement traumatized it regularly. The patient had become more concerned about the lesion after learning that a family friend had just received a diagnosis of melanoma. This concern was behind his visit.

The nodule was an impressive 3.2 cm in size and brownish black in color (see Figure 1). The surface looked and felt quite rough and warty. Small bits of the lesion could be scraped off easily. Further examination of the skin above the waist was unremarkable except for a few planar warty papules and plaques on the patient’s back.

This large lesion is most likely

A giant wart
Melanoma
Seborrheic keratosis
Carcinoma cuniculatum

Discussion

The correct answer is seborrheic keratosis. Completely benign, these wartlike lesions have a typical morphologic feature of being “stuck on” the skin, a feature they share with warts. When left untreated, seborrheic keratoses continue to grow, but few patients allow them to grow as large as the one in this case.

The dark brown color and large size rules out the diagnosis of wart, as warts seldom exhibit the color and size of this lesion. Melanomas are, by definition, part of the skin, not raised from the surface. It is always wise to have a pathologist examine a removed lesion, but melanoma is quite unlikely in this case. Carcinoma cuniculatum is a type of squamous cell carcinoma that develops in an old, large wart. While carcinoma cuniculatum is not the correct diagnosis in this case, removing the lesion and sending it to pathology can rule out that diagnosis as well.

Treatment This lesion was anesthetized locally, then shaved off the surface. The pathology report confirmed the diagnosis of seborrheic keratosis. Liquid nitrogen is of little benefit in a lesion of this size, and given the lesion’s epidermal nature, surgical excision is unnecessary.

Another phenomenon this case demonstrates is “the ripple effect,” in which almost every new diagnosis of melanoma prompts family, friends, and acquaintances to reevaluate their own lesions—as this patient did, even though he had been watching his lesion grow larger for 20 years. Seborrheic keratosis is among the most common lesions seen in dermatology practices and epitomizes what patients imagine melanoma must look like. This gives clinicians an opportunity to educate patients about melanoma and overall skin care.