Diagnosis and Treatment of Malignant and Premalignant Lesions

34 Diagnosis and Treatment of Malignant and Premalignant Lesions

Skin cancer is the most common cancer in the United States; fortunately, however, it is not one of the most common causes of death. Skin cancers are usually divided into melanoma and nonmelanoma skin cancers. An approximate breakdown of the most common skin cancers in the United States indicates that 80% are basal cell carcinomas (BCC), 16% squamous cell carcinomas (SCC), and 4% melanomas. Some of the rare skin cancers include Merkel cell carcinoma, dermatofibrosarcoma protuberans, and cutaneous T-cell lymphoma. These account for less than 1% of skin cancers.

Nonmelanoma skin cancer typically refers to BCC and SCC. Cutaneous metastases (of nonskin cancers), human papilloma virus–related cancers, tumors arising from dermal fibroblasts, neuroendocrine cells, and cutaneous lymphomas also occur. Both BCC and SCC have an increased incidence in people with fair skin, with increased sun exposure, and with aging. Patients with xeroderma pigmentosum have a very high rate of skin cancers due to sun exposure and UVB damage because they are unable to correct errors in their sun-damaged skin, leading to multiple skin cancers. SCCs are also more frequent in skin that is exposed to carcinogens or affected by chronic wounds or burns. BCCs very rarely metastasize, but can cause severe complications and even death from local invasion if left untreated. SCCs can metastasize although this is not common in skin lesions that are not on mucosal surfaces.

For melanoma, risk factors include family history, large congenital nevi, the familial atypical mole and melanoma syndrome (FAMMS; previously dysplastic nevus syndrome) (Figure 34-1) and sun exposure, particularly blistering burns in fair-skinned individuals. After initial biopsy, Breslow’s classification by depth of invasion is used to guide re-excision margins and the need for sentinel lymph node biopsy and to predict general survival rates.

In dealing with suspected skin cancer, the usual first step is to biopsy the lesion to confirm the diagnosis. For suspected melanoma, it is preferable to remove the lesion in its entirety with the initial biopsy if possible unless precluded by the size or location of the lesion. A deep shave (scoop shave) to diagnose melanoma can be done if the biopsy is deep enough to get under the entire lesion. Two or more 4- to 6-mm punch biopsies can often determine the diagnosis if the lesion is large and the clinician is not skilled at doing a deep shave. The risk of sampling error is greater with punch biopsies so a negative result may be a false negative. In SCCs and BCCs a shave biopsy is usually the easiest and least invasive way to get tissue to confirm the diagnosis. Having a histologic diagnosis can prevent a large unnecessary excision if the pathology turns out to be benign and can help guide the treatment of choice if malignancy is confirmed.

Actinic Keratoses, Actinic Cheilitis, and Bowen’s Disease

Actinic keratoses (AK), actinic cheilitis, and Bowen’s disease (SCC in situ) are all caused by cumulative sun exposure and have the potential to become invasive squamous cell carcinomas. The rate of malignant transformation has been variably estimated but is probably no greater than 6% per AK over a 10-year period.1 On a spectrum of malignant transformation, Bowen’s disease is squamous cell carcinoma in situ before the squamous cell carcinoma becomes invasive. In one large prospective trial, the risk of progression of AK to primary SCC (invasive or in situ) was 0.6% at 1 year and 2.6% at 4 years. Approximately 65% of all primary SCCs and 36% of all primary BCCs diagnosed in the study group arose in lesions that had been previously diagnosed clinically as AKs.2

Actinic keratoses are rough scaly spots seen on sun-exposed areas that may be found by touch, as well as close visual inspection. Bowen’s disease appears similar to actinic keratosis, but tends to be larger in size and thicker with a well-demarcated border (Figure 34-2). Actinic cheilitis is equivalent to AK but found on the lips (Figure 34-3).

Typical distribution of AKs and SCC in situ are the areas with greatest sun exposure such as the face, forearms, dorsum of hands, upper chest, lower legs of women, and the balding scalp and tops of the ears in men. Actinic keratoses that appear premalignant may be diagnosed by history and physical exam only and treated with destructive methods without biopsy. Bowen’s disease requires a biopsy for diagnosis. Bowen’s disease or squamous cell carcinoma should be biopsied prior to treatment. A shave biopsy should usually produce enough tissue for histopathology.

Treatment of Actinic Keratoses and Actinic Cheilitis



Electrodesiccation and Curettage (Single Cycle for AK)


Photodynamic Therapy

Treatment of Bowen’s Disease

The following is based on the guidelines from Cox et al.4:

There is reasonable evidence to support use of 5-fluorouracil (5-FU).4 It is more practical than surgery for large lesions, especially at potentially poor healing sites, and has been used for “control” rather than cure in some patients with multiple lesions.

One prospective study suggests that a curettage and electrodesiccation treatment is superior to cryotherapy in treating BD, especially for lesions on the lower leg.6 Curettage was associated with a significantly shorter healing time, less pain, fewer complications, and a lower recurrence rate when compared with cryotherapy.6

Photodynamic therapy has been shown to be equivalent to cryotherapy and 5-FU, either in efficacy and/or in healing.4 PDT may be of particular benefit for lesions that are large, on the lower leg, or at otherwise difficult sites, but it is costly.

See Table 34-1 for a summary of all recommended treatments for Bowen’s disease based on location and other characteristics.

Basal Cell Carcinoma


(See Table 34-2 for cure rates of BCC treatment modalities.)

Elliptical Excision (Fusiform) (Figure 34-9)

If you find evidence of the BCC at the base or edges (Figure 34-11) of the removed specimen, take another piece of skin or fascia at a deeper and/or wider level and put it in a second formalin container with a stitch used to mark its orientation in the body.


Electrodesiccation and Curettage


Mohs Micrographic Surgery (Figure 34-13)

Consider for H-zone on face (See Figure 37-12 on page 461), especially for recurrent BCC.8

Stay updated, free articles. Join our Telegram channel

Mar 12, 2016 | Posted by in General Surgery | Comments Off on Diagnosis and Treatment of Malignant and Premalignant Lesions

Full access? Get Clinical Tree

Get Clinical Tree app for offline access