A 58-year-old female visited a general dentist for an initial examination. During the extraoral exam, a red and scaly lesion was noted on her forehead.
Joen Iannucci Haring, DDS, MS
The patient was aware of the red, scaly area on the forehead and stated that it had been present for at least a couple of years, perhaps longer. The lesion was described as painless and had no history of bleeding. When questioned about prolonged or chronic sun exposure, the patient stated that she had spent considerable time outdoors during her lifetime. When questioned about her last medical visit, the patient stated that she last saw a physician several months earlier for treatment of high blood pressure.
The patient appeared to be in a general good state of health and denied any history of serious illness. A review of the medical history revealed hypertension controlled by medication. At the time of the dental appointment, the patient was taking medication for high blood pressure.
The patient`s blood pressure, pulse rate, and temperature were all found to be within normal limits. No enlarged lymph nodes in the head and neck region were detected upon palpation. Physical examination of the head and neck region revealed a white-and-red scaly plaque on the skin of the forehead measuring more than one centimeter in diameter (see photo). When palpated, the lesion had a sandpaper-like texture. Further examination of the skin revealed no other lesions present.
Based on the clinical information presented, which of the following is the most likely clinical diagnosis?
* seborrheic keratosis
* basal cell carcinoma
* squamous cell carcinoma
* actinic keratosis
Actinic keratosis (also known as senile keratosis or solar keratosis) is a pre-malignant lesion of the skin caused by excessive sun exposure. The term actinic refers to sun exposure and the term keratosis refers to the buildup of keratin, the principal constituent of the skin.
People with outdoor occupations (farmers, sailors, construction workers) and outdoor sportsmen (golfers, fishermen) are especially prone to developing actinic keratosis. In addition, individuals who lack pigmentation of the skin and have fair complexions are at greater risk for developing this lesion; people with light complexions who sunburn easily are most often affected. This condition is similar to actinic cheilosis of the lip (RDH September 1998) in both cause and behavior.
Actinic keratosis is typically seen in individuals over the age of 40 and occurs more frequently in men than in women. The most frequent areas of involvement include the face, neck, hands, forearms, and scalp. The lesions appear as scaly plaques which vary in color from white to gray or brown. The scaly plaques are superimposed on an erythematous background.
When palpated, actinic keratosis has a rough and sandpaper-like texture. The size may vary from less than 0.5 centimeters to more than 2 centimeters. Over time, actinic keratosis may become a heavily crusted area that does not resolve. Actinic keratosis is considered to be a precursor to skin cancer, specifically squamous cell carcinoma.
An estimated 13 to 25 percent of patients with actinic keratosis develop squamous cell carcinoma of the skin.
Diagnosis and treatment
Squamous cell carcinoma of the skin should be included in the differential diagnosis of actinic keratosis. The lesion must be submitted for a biopsy to rule out such a malignancy. Another lesion to include in the differential diagnosis is seborrheic keratosis, a benign skin lesion. The definitive diagnosis of actinic keratosis is made based on a biopsy and histologic examination of the lesion.
Treatment options for actinic keratosis include the following: cryotherapy, curettage, electrodesiccation or surgical excision.
Although recurrence is rare, long-term follow-up is recommended to screen for other lesions on the adjacent areas of sun-damaged skin. Because the skin of the head and neck is a highly visible and accessible area, both the dentist and dental hygienist can play an important role in the detection of this precursor to skin cancer. If actinic keratosis or skin cancer is suspected, the patient must be promptly referred to a physician for further evaluation and treatment.
Joen Iannucci Haring, DDS, MS, is an associate professor of clinical dentistry, Section of Primary Care, The Ohio State University College of Dentistry.