Chapter 29-5: Basal Cell Carcinoma

TEXTBOOK PRESENTATION

Basal cell carcinoma most commonly presents as a flesh-colored, translucent, or slightly red papule or nodule, classically displaying a rolled border. It most commonly presents on the head or neck of older adults.

DISEASE HIGHLIGHTS

1. Description of lesion: the typical lesion is a flesh-colored, translucent, or slightly red papule or nodule, classically displaying a rolled border (Figure 29-16).

   1. Lesions are often friable, bleeding easily and developing crust. Telangiectasias on the surface can be a helpful sign.

   2. Large tumors can be locally destructive.

2. Basal cell carcinoma is the most common malignant tumor in humans.

3. Lesions are typically asymptomatic except for the observation of easy bleeding from a site.

   1. Only rarely is pain associated.

   2. Metastasis from a basal cell carcinoma is rare.

4. Individuals at risk are adults with fair hair and eyes, easy freckling, and propensity for sunburn.

   1. Patients with skin of color are less likely to be affected.

   2. Men and women are about equally affected.

   3. Exposure to UV light has long been believed to play a causative role in the development of this tumor, although the exact mechanism is not clear. Several genetic mutations have been isolated in basal cell carcinoma and may serve as targets for therapeutics.

   4. Chronic wounds and sites of inflammation, as well as, immunosuppression can predispose to development of this tumor.

   5. Exposure to arsenic is another risk factor for basal cell carcinoma.

5. The head and neck are the most common sites affected with this tumor.

   1. Only 10–15% of tumors develop on sun-protected skin.

   2. The nose is the most common site, accounting for 20–30% of all cases.

6. Basal cell carcinoma is likely derived from the hair follicle. The name implies a resemblance of the tumor cells to the basal cells of the epidermis, although this is not believed to be their derivation.

7. Patients have up to a 45% risk of developing subsequent basal cell carcinomas in the 5 years after initial diagnosis.

EVIDENCE-BASED DIAGNOSIS

Histologic evaluation of affected tissue is the gold standard for diagnosis.

TREATMENT

1. The goal of therapy is to eliminate the tumor and prevent local tissue destruction. Numerous methods are available to accomplish this goal, and selection depends on tumor size, type, and location, patient characteristics, and patient preferences.

2. 5-year recurrence rates vary by treatment modality. The lowest recurrence rate is achieved with Mohs micrographic surgery.

   1. This method involves excision of the visible tumor, followed by microscopic evaluation of frozen tissue sections to visualize tumor margins and repeat local excision until all margins are clear of tumor.

   2. The technique allows for maximal tissue sparing while ensuring complete eradication of tumor.

3. Follow-up of patients for recurrent or subsequent tumors is critical.