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How to examine a patient with suspected skin cancer
Medicine, 6, 37, pages 303 - 304
Skin cancer rates are rising dramatically. The condition is now being seen on a daily basis by all healthcare professionals, not only dermatologists and plastic surgeons. As a result, there is a crucial need to educate all these groups on recognizing patients with this cancer. The basic rule of physical examination applies, with due emphasis on precise and methodical visual inspection supplemented by gentle palpation.
Keywords: examination, skin cancer, skin phototype.
Skin cancer is the most common malignancy in the UK and, unlike cancer of other organs, it is there for all of us to see. It is one of the diseases where early detection and treatment are critical. Skin cancers treated early are curable with relatively simple therapies, whereas advanced disease often has no effective treatment available. Early detection of skin cancer should be the goal of all healthcare professionals who have an opportunity to look at the skin.
The first step in evaluation of the skin cancer patient must include a thorough history, focusing on general medical and drug history, personal or family history of skin cancer, numbers of moles including presence of dysplastic naevi 1 and a comprehensive social history, including carcinogen exposure (arsenic, ionizing radiation, industrial oils and hydrocarbons) and sun exposure or sunburn history. The Fitzpatrick scale of skin phototype ( Table 1 ) may be used to identify those at higher risk for UV-produced erythema and subsequent complications.
|Skin type||Colour||Reaction to ultraviolet radiation|
|1||Pale white skin, blue/hazel eyes, blond red hair||Always burns, never tans|
|2||Fair skin, blue eyes||Burns easily, rarely tans|
|3||White to olive||Tans after initial burn|
|4||Light brown||Burns minimally, tans easily|
|5||Brown||Rarely burns, easily tans darkly|
|6||Dark brown to black||Never burns, always tans darkly|
Examination of the patient’s skin requires a private, warm and well-lit room provided with an examination couch, appropriate drapes and a chaperone as required. Examination of the skin itself depends principally on visual inspection and its permutations (magnification loupes, polarized light examination and dermoscopy ( Figure 1 )) supported by gentle palpation.
How to examine
There should be a method to the examination that allows for visual scanning of the entire surface of the patient’s skin before focusing on individual suspect lesions. The feet and hands including the palms, nails and areas between the toes and fingers should be examined. The anterior of the body then the posterior surface should be examined, including the intertriginous areas. If the patient gives consent, the border zones of the oral and ocular mucosae and genital area should also be examined. Special attention should be paid to the head and neck region, and the scalp should also be examined with a combination of direct visual examination and palpation. The specific details of diagnosing skin lesions are covered elsewhere in this chapter (see pp. 305–308) but this should not deter inexperienced examiners as the human eye is well designed to detect irregularities in patterns (‘duck in a flock of chickens’ rule). This can then serve to prompt more precise diagnosis.
Dermascopic examination of individual lesions can allow visualization of deeper layers of the skin and, in expert hands, can be useful. However, practitioners must be trained in its use and the significance of dermascopic changes.
In the most common skin cancers, the genetic traits of an individual form the base upon which environmental factors established over a period interplay to result in disease. Pale complexion, light-coloured eyes, red or blond hair (related to non-functioning MC1R mutations 2 ), freckles and a Northern European or Celtic background are important risk factors. The melanin type (black-brown eumelanin or red-yellow pheomelanin 3 ) and content appear to determine an individual’s response to ultraviolet radiation.
Solar elastosis (a yellowed puckered change in the skin) and precancerous solar keratoses (scaly skin patches) can be considered a marker of previous chronic solar damage. Squamous cell carcinoma (SCC) is more common in outdoor workers and occurs on body sites of maximum sun exposure. The ears and lower lips are frequently unprotected and may be exposed to co-carcinogens, e.g. tobacco. SCC at these sites is more aggressive, with a significantly higher risk of metastases. 4
The presence of more than 50 benign moles, atypical naevi, naevi on the buttocks or feet are recognized risk factors for development of malignant melanoma, 5 especially where there is a family history of melanoma. Malignant melanoma and basal cell carcinoma appear to be associated with a history of sunburns in childhood, and in indoor workers with a history of intermittent intense solar exposure. Malignant melanoma is more common on the legs in women and on the trunk in men. Acral melanomas are frequently misdiagnosed and are the most common type of malignant melanoma in coloured skin. The nails should be examined for abnormalities such as linear pigmentation (linear melanonychia) and dark patches under the nail and on the nail fold due to nail matrix melanoma.
Peri-ocular skin cancers, especially basal cell carcinoma, can be very subtle; if unrecognized and neglected they may lead to globe loss or intracranial tumour extension. Examine the medial canthal regions, and beware of asymmetrical eyelash loss and unexplained ectropion. Ask the patient to close their eyes to examine the upper eyelid skin.
Any suspicious lesions identified should be carefully evaluated using magnification and dermoscopy or further imaging if the examiner is expert at these modalities. Any lesion suspected of skin cancer should be subjected to biopsy and histopathology examination. If a skin cancer is diagnosed then regional draining lymph nodes should be examined and in cases of melanoma a directed clinical examination should be performed.
Baseline whole-body photography with standardized views is often used to supplement clinical examination and is particularly useful for ongoing follow-up of high-risk patients who ideally would benefit from an annual physician-based skin examination. 6 The early detection of skin cancer is the key to cure, especially in cases of malignant melanoma. There are many highly sensitive mole-imaging systems available on the market which may identify lesions that might ordinarily be missed using standard clinical tools. Their specificity, however, is low and the expense and their general use at this stage is controversial. 7
- 1 W.H. Clark Jr., R.R. Reimer, M. Green, et al. Origin of familial melanomas from heritable melanocytic lesions.’The B-K mole syndrome’. Arch Dermatol. 1978;114:732-738 Crossref
- 2 J.L. Rees. The genetics of sunsensitivity in humans. Am J Hum Genetics. 2004;75:739-751 Crossref
- 3 G. Prota. Melanins, melanogenesis and melanocytes; looking at their functional significance from the chemist’s viewpoint. Pigment Cell Res. 2000;13:283-293
- 4 D.E. Rowe, R.J. Carroll, C.L. Day. Prognostic factors for local recurrence, metastasis, and survival rates in squamous cell carcinoma of the skin, ear and lip. J Am Acad Dermatol. 1992;26:976-990 Crossref
- 5 J.A. Newton Bishop, R.C. Wachsmuth, M. Harland, et al. Genotype/phenotype and penetrance studies in melanoma families with germline CDKN2A mutations. J Invest Dermatol. 2000;114:28-33
- 6 A.W. Kopf, W. Slue, J.K. Rivers. Photographs are useful for detection of malignant melanoma in patients who have dysplastic naevi. J Am Acad Dermatol. 1988;19:1132-1134 Crossref
- 7 M.A. Haniffa, J.J. Lloyd, C.M. Lawrence. The use of a spectrophotometric intracutaneous analysis device in the real-time diagnosis of melanoma in the setting of a melanoma screening clinic. Br J Dermatol. 2007;156:1350-1352 Crossref
Thomas Ha MD FRACP FRCP is Consultant Dermatologist at Addenbrooke's Hospital, Cambridge, UK. Competing interests: none declared
© 2009 Elsevier Ltd, All rights reserved.