Verrucous nodules on the ankle
The scaly nodules appeared over the staple sites of a previous surgery. But did one have anything to do with the other?
Chromoblastomycosis is a deep fungal infection most commonly caused by the pigmented fungus Phialophora verrucosa found in tropical climates.4 The fungi enter the skin of the lower extremity after minor trauma, resulting in a gradually expanding verrucous nodule or plaque. The nodular variant is often pedunculated with classic pigmented cauliflower-like florets. While the nodular variant is localized, the plaque variant may spread laterally, possibly metastasizing through lymphatic channels with a concomitant bacterial infection. There is also a characteristic unpleasant odor with lymph stasis.
On potassium hydroxide (KOH) mounts or histologic examination, the thick-walled cells (muriform bodies) of chromoblastomycosis are diagnostic. Patients with chromoblastomycosis have seen response rates >60% with 10 to 24 months of daily itraconazole (200 mg) therapy.5
Squamous cell carcinoma (SCC) is the second most common skin cancer and affects more than 250,000 Americans each year. While associated with sun exposure, it has also been linked to ionizing radiation, arsenic, human papilloma virus, cigarette smoking, and chronic nonhealing wounds and scars such as Marjolin’s ulcer.1
Marjolin’s ulcer usually appears as a triad of nodule formation, induration, and ulceration at a scar site and thus may be confused with HLP. It is more common than sun-induced SCC in Asian and dark-skinned individuals.6 Marjolin’s ulcer will usually present in the fifth decade, years after the initial insult. Diagnosis is supported by the clinical appearance and history of a preceding scar at the site. Marjolin’s ulcer has a higher rate of recurrence and metastasis than other forms of SCC, and thus should be treated aggressively.7,8
A biopsy may be needed
A drop of immersion oil can confirm your HLP suspicions by revealing the white, lacy reticular network of Wickham’s striae.1 Other clinical clues to the diagnosis of LP or one of its variants include a white reticular, erythematous, or ulcerative appearance on the buccal mucosa in addition to a dorsal pterygium and/or diffuse pitting on the nails.
