What do you suspect is the cause of the ulcer?

A 57-year-old white male with a history of diabetes and hypertension presents with a 3-month ulcer on his left, plantar foot. The enlarging ulcer, associated with sporadic pain, sent the patient to a vascular surgeon—who preformed an extensive work up that included x-rays, arterial, and venous dopplers. All studies were found to be unremarkable.

(Answer and on next page)

Answer: Malignant Ulcer

The result of a skin biopsy confirmed a clinical suspicion that the plantar lesion was an ulcerated, acral lentiginous melanoma. Unfortunately, the melanoma metastasized to the patient’s liver, pancreas, lungs, and thalamus. The patient died within 2 years of the diagnosis. Early detection and excision would have prevented the metastasis.

Typically, venous stasis ulcers occur in the gaiter area—most commonly at medial malleolus and rarely form on the plantar foot. Arterial (ischemic) ulcers usually occur on the distal leg or on the dorsum of foot or toes and do not typically form on the plantar foot. While neurotrophic (diabetic) ulcers can occur on the plantar foot, these ulcers are not painful.

When foot ulcers fail to heal or do not fit typical clinical presentations as described above, a skin biopsy is needed to rule out malignancy. A number of cancers including squamous cell carcinoma, lymphoma and melanoma can present with ulceration on the foot.

Reference
Spentzouris G, Labropoulos N. The evaluation of lower-extremity ulcers. Semin Intervent Radiol. 2009; 26(4):286-295.

Kristina Paley, MD, shares her first-hand account of the case here: