Non-healing, non-tender ulcer on shin

Diagnosis: Infiltrative basal cell carcinoma

In addition to our patient’s history of venous insufficiency, he’d also had a melanoma removed from his right shoulder 6 years earlier, and a basal cell carcinoma (BCC) removed from his upper back 2 years earlier. The chronic, non-healing nature of the ulcer prompted us to perform a punch biopsy, which revealed infiltrative BCC. We also did a wound culture, which showed a secondary infection with methicillin-resistant Staphylococcus aureus (MRSA). The verrucous plaques next to the ulcer were the result of chronic venous stasis and lymphedema.

BCC is the most common type of cancer, estimated to comprise 80% of all skin cancers.¹ It typically presents on the head and neck, but can occur in other locations. Eight percent of BCCs occur on the legs.^2,3 Lower extremity BCC is more common in women, likely due to increased ultraviolet radiation exposure.^2,4

It's not known whether squamous cell carcinoma or basal cell carcinoma arise independently—or secondary—to chronic leg ulcers.

BCC presents as erythematous and pearly macules, papules, nodules, ulcers, or scars, and can be pigmented. It may appear as a crusted ulcer (known as a “rodent ulcer”) with a rolled, translucent border and telangiectases.⁵ There are 5 major histologic subtypes of BCC: nodular, micronodular, superficial, morpheaform, and infiltrative.^1,5 Infiltrative BCCs are an invasive subtype^1,5 and may be more commonly associated with severe venous stasis,³ as was the case with our patient.

Although considered uncommon, squamous cell carcinoma (SCC) and BCC have been discovered in chronic leg ulcers.^4,6 In fact, one report suggests that as many as 10% of chronic leg ulcers are malignant (31% BCC, 56% SCC).⁷ Thus, it is important to maintain a high index of suspicion for malignancy in chronic leg ulcers.