Rodent Ulcer_0212 Derm Dx
Rodent Ulcer Close-Up_0212 Derm Dx
At the insistence of her daughter, a 72-year-old woman sought treatment for a deep nasal ulceration that had perforated the skin and cartilage and exposed her nasal septum. The lesion occasionally bled but otherwise caused minimal symptoms.
The patient wore a large bandage whenever she was in public. Years earlier, she had had a nasal growth removed by her general practitioner, who has since died. She failed to seek further medical attention when the growth returned about 10 years ago. What’s your diagnosis?
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The lesion is a rodent ulcer. Often considered a synonym for basal cell carcinoma (BCC), “rodent ulcer” classically describes a skin cancer that has significantly invaded dermal tissues. The term underscores the capability of BCC to produce extensive local tissue destruction including cartilage and bone.
BCC is a malignant, cutaneous epithelial tumor derived from alterations in basal cells from the Malpighian layer of the epidermis. Tumors are slow-growing, often taking 10 years to reach the size seen in our patient. BCC occurs predominantly after the age of 60, but the lesions can appear in the third decade in patients with moderate-to-severe actinic skin damage.
Although BCC occurs on any skin surface, the most common sites are the head and neck, followed by the shoulders and upper trunk. BCC does not occur on the mucous membranes except by adjacent invasion. The tumors normally occur de novo on the face, but they can follow trauma, such as burns, x-rays and vaccinations.
Nevoid lesions in which BCC can occur include nevus sebaceum and epidermal nevus. Genetic syndromes including xeroderma pigmentosa, basal cell nevus syndrome and Bazex syndrome are also associated with basal cells. There is a relationship between BCC and chronic UV exposure; however, the most important contributing factor is likely an inability to immunologically patrol and destroy aberrant epidermal cells.
BCC is the most common skin cancer among Caucasians, and epidemiologic studies in North America note that incidence of these tumors is increasing and occurring more frequently in younger patients.
BCC often appears as a translucent pearly papule or nodule with telangiectasias and possibly central ulceration. Left untreated, lesions will continue to expand peripherally while the center remains ulcerative or sclerotic with an elevated, telangiectatic border. Neglected lesions can be extremely destructive and disfiguring. Metastasis is rare, with fewer than 150 cases reported. In 30 years, I have not seen one BCC metastasize, although I have seen one invade the cranium.
A superficial variety of BCC appears as an erythematous, slightly scaling, well-demarcated patch with a threadlike pearly border. Rarely, a morphea-like form of BCC presents as a yellow-white, indurated plaque with ill-defined borders, resembling scleroderma. Occasional pigmentation in a BCC can obscure the lesion’s features, causing clinical confusion with other entities, such as seborrheic keratosis and melanoma.
The striking feature of the rodent ulcer is a hard rolled edge of cartilaginous consistency and pearly white color. The lesion has a tendency to improve and to appear to heal with or without scarring, which can give rise to false hopes that may last for years.
Classic nodular BCC presents little clinical diagnostic difficulty, but many lesions are only suggestive of cutaneous malignancy and biopsy is needed for an accurate diagnosis. Thus, the differential diagnosis of BCC includes dermatofibroma, nonpigmented nevus, seborrheic keratosis, pyogenic granuloma, sebaceous hyperplasia, squamous cell carcinoma, lupus erythematosus, Bowen’s disease, trichoepithelioma, cylindroma, eccrine acrospiroma and some sweat-gland carcinomas.
The most common treatment approaches are surgical excision and electrodesiccation and curettage. Cure rates average well above 90% in most studies.
Mohs surgery, which involves chemical in vivo fixation of cutaneous tissue, followed by serial excision and microscopic control, offers a high cure rate. At a cost of about $6,000 per lesion, Mohs surgery is usually reserved for difficult tumors, e.g., recurrent lesions in the nasolabial fold or the periorbital or periauricular regions.Radiation is also effective, especially for lesions with ill-defined margins or in difficult locations and for patients who should avoid surgery. Some success has been reported with topical imiquimod and topical 5-fluorouracil.
The FDA recently approved the oral therapy vismodegib (Erivedge, Genentech Inc.), for the treatment of metastatic BCC and for locally advanced BCC in patients who are eligible for radiation therapy or surgery.
Our patient’s tumor needed extensive surgical excision and reconstructive surgery. A member of my staff scheduled an appointment with a plastic surgeon and conducted follow up with phone calls to ensure that the surgery was undertaken.
Craig G. Burkhart, MD, MPH, is a clinical professor of dermatology in the department of medicine, at the University of Toledo College of Medicine in Ohio.