CASE #1: Basal cell carcinoma
The patient had basal cell carcinoma (BCC), the most commonly diagnosed skin cancer. BCC proliferates in the basal cell layer of the epidermis. It rarely metastasizes but is locally invasive and can be aggressive, causing destruction of the surrounding tissues. Caucasian men are more commonly affected than women or individuals with darker skin. As patients age, their chance of developing BCC increases, and the number of cases has grown steadily with the rise in life expectancy of Americans in the past 20 years.1
BCC has both genetic and environmental risk factors. Mutations in the PTCH gene located on chromosome 9 predispose one to basal cell nevus syndrome, which includes developmental anomalies and multiple postnatal tumors, including BCCs.2 The most important environmental risk factor is UV light exposure,3 both early childhood and recent exposure. Additional factors include smoking,4 chronic arsenic exposure,5,6 and therapeutic radiation.7
Lesions of BCC always occur on sun-exposed areas; a history of long-term sun exposure is uniformly present. Actinic keratoses are common associated findings. BCC lesions often exhibit scale or crust, and bleeding is not unusual. The clinical presentation of BCC can vary; morphologic descriptions include nodular, superficial, and sclerosing.
Nodular BCC, which is what our patient had, is the most common subtype. Translucent papules typically occur on the face and are pearly, yellowish, or flesh-colored. Telangiectasias are seen just under the surface. An ulcerated center (so-called rodent ulcer) can be seen. Superficial BCCs comprise 30% of all BCC lesions and generally occur on the trunk. These growths typically exhibit scaly plaque, usually light red in color, with a rim of fine micropapules surrounding the border. Sclerosing BCCs are the least common (5%-10%) but most aggressive subtype. They present as smooth, flesh-colored, atrophic plaques with ill-defined edges.
Differential diagnoses for early nodular BCC include benign entities, such as dermal nevi and epidermal inclusion cysts, as well as malignancies, such as sebaceous carcinomas and amelanotic melanomas. Larger lesions with central ulceration can resemble squamous cell carcinoma, keratoacanthomas, or neurofibromas. BCC is frequently mistaken for sebaceous hyperplasia because both are pearly to yellow in color, are umbilicated or have central depression, and are often located on the face.
Biopsy will confirm a diagnosis of BCC. Invasive basaloid cells with a peripheral palisading appearance are seen. Treatments include Mohs surgery, excision, and electrodesiccation with curettage. Our patient underwent Mohs excision, with primary closure performed by oculoplastic surgery. Because he has a history of sun damage and extensive actinic keratosis, recommended follow-up included annual total-body skin examinations. To date, his lesion has not recurred.