04 Malignant Skin Lesions

19 precursor lesions unlike bccs sccs often arise in

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: iated with SCC is estimated to be approximately 1/100,000.19 Precursor Lesions Unlike BCCs, SCCs often arise in precursor lesions, such as actinic keratoses.20 Actinic keratoses, sometimes referred to as solar keratoses, develop in chronically sun-damaged areas of the body. These lesions are often multiple, are generally ill-defined and irregular, and may range in size from about 1 mm to a few centimeters. They have a scaly appearance and exhibit a wide variety of colors, from dark brown to flesh-pink. Biopsy may be necessary to rule out the presence of a SCC. Although the rate at which actinic keratosis undergoes malignant transformation to SCC is less than 0.1% per year,21 lesions should nevertheless be treated to reduce the chances of progression. Treatment options include cryotherapy, curettage, and topical therapy. Surgical excision of actinic keratoses is rarely necessary but may be indicated if there is a high level of suspicion for concurrent SCC. Intraepithelial SCC (carcinoma in situ), also known as Bowen disease, is thought to be the next step in the progression from actinic keratosis to invasive SCC.The lesions are typically located on sunexposed areas of the head, neck, trunk, or legs; when they are located on the genitalia, the condition is referred to as erythroplasia of Queyrat. Lesions that develop on non–sun-exposed areas may be associated with internal malignancy.22 Intraepithelial SCCs typically appear as erythematous, slightly keratotic plaques and are usually larger than the lesions of actinic keratosis. They should be excised with a 5 mm to 1 cm margin. Diagnosis As noted (see above), SCCs are most often associated with sun exposure, though they may also be seen in patients with old scars, radiation-damaged skin [see Figure 2a], or chronic open wounds.23 Chronic inflammation and irritation appear to be the common denominators. SCC that arises in a burn scar or a chronic, open wound overlying osteomyelitis is often referred to as a Marjolin ulcer. SCCs that develop from Marjolin ulcers are characterized by aggressive regrowth after incomplete biopsy. SCCs typically appear as reddish-brown, pink, or flesh-colored keratotic papules [see Figure 2b]; ulceration is sometimes, though not always, present. If there is extensive hyperkeratosis, a cutaneous “horn” may be evident.18 Symptoms that may suggest malignant transformation of actinic keratosis into SCC include pain, erythema, ulceration, and induration. Histologically, SCCs are characterized by nests of atypical keratinocytes that have invaded into the dermis, which may be either well or poorly differentiated. Once the diagnosis of SCC is suspected, careful attention should be paid to the draining nodal basins with the aim of detecting possible lymph node metastasis. The risk of such metastasis is between 2% and 4% overall but is somewhat higher in patients with relatively large and poorly differentiated lesions and in patients with lesions located on the scalp, the nose, the ears, the lips, or the extremities. The most...
View Full Document

This note was uploaded on 03/21/2011 for the course ONC 01 taught by Professor Dzodic during the Spring '11 term at Multimedia University, Cyberjaya.

Ask a homework question - tutors are online