What is the most likely diagnosis?A 45-year-old white woman presents to your office concerned about a “mole” on her face. She says that it has been present for years but her husband has been urging her to have it checked. She denies any pain, itching, or bleeding from the site. She has no significant past medical history, takes no medications, and has no allergies. She has no history of skin cancer in her family. She is an accountant by occupation.
On examination, the patient is normotensive, afebrile, and appears slightly younger than her stated age. A skin examination reveals a nontender, symmetric, 4-mm papule that is uniformly reddish-brown in color. The lesion is well circumscribed, and the surrounding skin is normal in appearance. There are no other lesions in the area.
What is the most likely diagnosis?
What features are reassuring of a benign condition?
What is your next step?
Summary: A 45-year-old healthy woman with no significant past medical history presents for evaluation of a skin lesion. She does not have a family history of skin cancer. The lesion is symmetric, with well-defined borders, relatively small (<6 mm), and uniform coloration. She is not able to assess whether the lesion has changed recently (ie, become larger), and does not give a history of itching or bleeding at the site of the lesion.
• Most likely diagnosis: Benign nevus
• Reassuring features: Size less than 6 mm, symmetric, uniform color, well-defined borders
• Next step in treatment: Reassurance and surveillance
1. Describe an approach to the evaluation of skin lesions.
2. Be able to describe the features of a skin lesion in dermatologic terms.
3. Know which features of a lesion are typically benign and which are concerning for malignancy or potential malignancy.
This case represents a typical scenario seen in primary care medicine: “I have this mole. Is it cancer?” Although simplified, this is what the patient is most concerned about and wants to know. The role of the physician is to determine the likelihood of malignancy or premalignancy and to define a course of action that is appropriate. In this particular case, there are several features that reassure a benign condition that can be monitored without the need for a biopsy. There was neither a family medical history of skin cancer nor history of skin cancer in the patient. She has an occupation that does not expose her to harmful chemicals or the sun on a regular basis. On examination, the lesion has typically benign features (size <6 mm, symmetric, uniform color, well-defined borders). In this case, it would be appropriate to make a note (or possibly even a photograph) in the patient’s chart describing the characteristic features of the lesion and monitor for changes in the lesion at periodic health evaluations. The patient should also be educated in self-examination of the skin, with an emphasis on what to look for and when to come to the physician’s office for an evaluation of a new or changing skin lesion. Finally, it should be understood that many otherwise benign-appearing moles might have an atypical characteristic that warrants further investigation. The criteria that are used to predict the likelihood of a benign versus malignant lesion are only guidelines; to be sure, not all malignant skin lesions present in the same manner and a malignant melanoma is not always visibly pigmented. The bottom line is that the physician should use all of the tools at his disposal: the history of present illness (HPI), medical history of the patient, the family medical history (FMH), social and occupational history, and a pertinent review of systems so as to arrive at a conclusion that is consistent with the physical examination.
ABSCESS: A closed pocket containing pus
BULLA: A blister greater than 0.5 cm in diameter (plural: bullae)
CYST: A closed, saclike, membranous capsule containing a liquid or semisolid material
MACULE: A discoloration on the skin that is neither raised nor depressed.
NODULE: A small mass of rounded or irregular shape that is greater than 1.0 cm in diameter
PAPULE: A small, circumscribed elevated lesion of the skin that is less than 1.0 cm in diameter
PLAQUE: A plateaulike, raised, solid area on the skin that covers a large surface area in relation to its height above the skin
ULCER: A lesion through the skin or mucous membrane resulting from loss of tissue
VESICLE: A small blister less than 0.5 cm in diameter
There has been an increase in the morbidity and mortality of skin cancer in the past few decades in the United States. In 2010, over 68,000 new cases of melanoma were diagnosed. When you include basal cell carcinoma or squamous cell carcinoma, more than 1 million new cases of skin cancer are diagnosed annually. Skin cancers cause approximately 10,000 deaths per year, of which 80% are due to melanoma.
The single most important risk factor for the development of skin cancer is exposure to ultraviolet radiation. Other risk factors include a prior history of skin cancer, a family history of skin cancer, fair skin, red or blonde hair, a propensity to burn easily, chronic exposure to toxic compounds such as creosote, arsenic, or radium, and a suppressed immune system.
This is the most common type of melanoma in both sexes. As its name implies, this lesion spreads superficially along the top layers of skin before penetrating into the deep layers. The superficial, or radial, growth phase is slower than the vertical phase, which is when the lesion grows into the dermis and can invade other tissues or metastasize. Men are more commonly affected on the upper torso, whereas women are affected mostly on the legs. Common clinical features include: raised borders and brown lesions with pinks, whites, grays, or blues.
Similar to the superficial spreading type, this lesion is most often found in the elderly (commonly diagnosed in the seventh decade of life), usually on chronic sun-damaged skin such as the face, ears, arms, and upper trunk. Although it is the least common of the four types of melanoma, this is the most common form of melanoma found in Hawaii. They are clinically characterized as tan to brown lesions with very irregular borders.
Similar to the other two superficial melanomas in that it begins in situ, this lesion is different in many ways. This is the most common melanoma found in African Americans and Asians. This melanoma is usually found under the nails, on the soles of the feet, and on the palms of the hands; common clinical features include: flat, irregular, dark brown to black lesions.
This melanoma, unlike the other three, is usually invasive at the time of diagnosis. This is the most aggressive and second most common type of melanoma (Figure 13–1). They are clinically characterized as brown to black lesions that arise from nevi or normal skin.
Figure 13–1. Nodular melanoma. (Reproduced, with permission, from Kasper DL, Braunwald E, Fauci A, et al. Harrison’s Principles of Internal Medicine. 16th ed. New York, NY: McGraw-Hill; 2005:499)
In 1985, it was noted by clinicians studying melanoma that there were several characteristic features of skin lesions that correlated with melanoma. Specifically, color variegation, border irregularity, asymmetry, and size greater than 6 mm in diameter were consistently observed with melanoma. This led to the ABCD acronym, which has been used extensively to determine the likelihood of a cancerous skin lesion (Table 13–1).
Table 13–1 • CLASSIC ABCD CRITERIA OF SUSPICIOUS SKIN LESIONS
One other criterion that is often used is the change in the size or appearance of the skin lesion. This is sometimes cited as E in the above ABCD criteria, and referred to as Evolving and Elevation. Benign lesions may present at birth, or any time thereafter, and several benign lesions may also present near the same point in time. However, a benign lesion, once present, will usually remain stable in size and appearance, whereas a malignancy will present as increasing in size or changing in appearance. Thus, it is useful to ask whether a “mole” has recently changed in appearance or has grown in size.
Benign nevi need only be monitored visually. The patient can accomplish this after education on what to look for and when to come back for reevaluation. In general, any preexisting nevus that has changed or any new pigmented lesion that exhibits any of the ABCDE signs should be excised completely with a 2- to 3-mm margin around the lesion. Larger lesions that may be cosmetically difficult to completely excise may be biopsied in several areas. If the pathology indicates a malignancy, the lesion should then be completely excised with 5-mm margins by a physician trained in plastic surgical technique. Complete excision of malignant melanomas requires at least a 5-mm margin. Once a patient has been identified as having a malignant skin lesion, the patient should be observed on an annual basis for any new or changing skin lesions. Shave biopsy may be used for raised lesions, and punch biopsy or elliptical excision for flat lesions. If the entire lesion cannot be removed due to size or location, biopsies should be taken from the most suspicious parts of the lesion.
The single most important piece of information for prognosis in melanoma is the thickness of the tumor, known as the Breslow measurement. Melanomas less than 1-mm thick have a low rate of metastasis and a high cure rate with excision. Thicker melanomas have higher rates of metastases and poorer outcomes.
Prevention is aimed at reducing exposure to ultraviolet radiation. When possible, avoid the sun between 10 AM and 4 PM; wear sun-protective clothing when exposed to sunlight; wear a sunscreen with a sun protection factor (SPF) of at least 15; and avoid artificial sources of ultraviolet (UV) radiation.
Both basal cell and squamous cell carcinomas arise from the epidermal layer of the skin. The primary risk for these types of skin cancers is exposure to ultraviolet radiation, especially sun exposure but also tanning bed use. A history of actinic keratoses and human papillomavirus infection of the skin also raises the risk of squamous cell carcinomas.
Basal cell carcinomas are the most common of all cancers. They typically appear as pearly papules, often with a central ulceration or with multiple telangiectasias. Patients typically present with a growing lesion and sometimes complain that it bleeds or itches. Basal cell carcinomas rarely metastasize but can grow large and can be locally destructive. The primary treatment is excision.
Squamous cell carcinomas have a higher rate of metastasis than basal cell carcinomas, but the risk is still low. These lesions are often irregularly shaped plaques or nodules with raised borders. They are frequently scaly, ulcerated, and bleed easily. Complete excision is the treatment of choice.
13.1 A 36-year-old man is noted to have a bothersome “mole” that on biopsy reveals malignant melanoma. The pathologist comments that this histology is the most common type of melanoma in both males and females and has two growth phases. Which of the following is the most likely finding?
A. Benign nevus
B. Superficial spreading melanoma
C. Lentigo maligna
D. Nodular melanoma
E. Acral lentiginous melanoma
13.2 A 49-year-old fair skinned woman is noted to have a lesion on her right upper back that seems to have grown over the past year. It is noted to be 8 mm in diameter. The physician obtains an excisional biopsy, and it returns as malignant melanoma with invasion. Which of the following is the most likely finding on the biopsy?
A. Benign nevus
B. Superficial spreading melanoma
C. Lentigo maligna
D. Nodular melanoma
E. Acral lentiginous melanoma
13.3 A 54-year-old African-American man is noted to have a dark “spot” on his palm of his hand that his wife has noticed has become irregular in shape. On biopsy, it is a malignant melanoma. Which of the following is the most likely histology in this patient?
A. Benign nevus
B. Superficial spreading melanoma
C. Lentigo maligna
D. Nodular melanoma
E. Acral lentiginous melanoma
13.4 A 45-year-old African-American woman presents for a routine examination. You notice a 9-mm-diameter lesion on the palm of her right hand that is dark black, slightly raised, and has a notched border. When asked about it, she says that it has been present for about a year and is growing. A friend told her not to be concerned because, “black people don’t get skin cancer.” Which of the following is your advice?
A. Her friend is correct and this is nothing to worry about.
B. While anyone can get skin cancer, this lesion has primarily benign features and can be safely observed.
C. This lesion is suspicious for cancer but this is most likely a metastasis from another source, such as a breast cancer.
D. This lesion is suspicious for a primary melanoma and needs further evaluation immediately.
13.5 A 70-year-old woman presents for evaluation of a lesion on her left cheek. It has been present for several months. It is slowly enlarging and bleeds if she scratches it. On examination, you find a 7-mm-diameter pearly appearing papule with visible telangiectasias on the surface. Which of the following is the appropriate management of this lesion?
A. Close observation and reexamination in 3 months
B. Reassurance of the benign nature of the lesion
C. Excision
D. Local destruction by freezing with liquid nitrogen
13.1 B. Superficial spreading melanomas are the most commonly occurring melanomas in both men and women.
13.2 D. Nodular melanomas are the most aggressive melanomas and are usually invasive at the time of diagnosis. This patient’s lesion has grown quickly and is invasive.
13.3 E. Acral lentiginous melanomas are found on the palms of hands, soles of feet, and under finger- and toenails, and are the most common type found in African Americans and Asians.
13.4 D. The lesion described is suspicious for an acral lentiginous melanoma and needs evaluation. While skin cancers are more common in persons with lighter skin, they can occur in persons with any skin color or tone.
13.5 C. The lesion is most likely a basal cell carcinoma and should be treated with excision. While the likelihood of metastatic spread is low, these lesions can grow and be locally destructive.
The preventable risk factor common to all skin cancers is sun exposure. Recommend to your at-risk patients limiting exposure to sunlight in the middle of the day, wearing appropriate protective clothing, and using sunscreen.
Contrary to popular belief, the use of tanning beds is also a risk factor for skin cancer.
There is no such thing as a “healthy tan.”
Excisional biopsy should be done for any lesion suspicious for melanoma. If the entire lesion cannot be removed due to size or location, full-thickness biopsies should be taken from the most suspicious parts of the lesion.
Abbasi NR, Shaw HM, Rigel DS, et al. Early diagnosis of cutaneous melanoma: Revisiting the ABCD criteria. JAMA. 2004;292:2771-2776.
Cooke D, Englis M, Morriss J. Melanoma precursors and primary cutaneous melanoma. In: Fitzpatrick TB, Johnson RA, Wolff K, et al. eds. Color Atlas & Synopsis of Clinical Dermatology. 4th ed. New York, NY: McGraw-Hill; 2001.
Ebell M. Clinical diagnosis of melanoma. Am Fam Physician. 2008;78(10):1205-1208.
Goldstein BG, Goldstein AO. Diagnosis and management of malignant melanoma. Am Fam Physician. 2001;63:1359-1368, 1374.
Rager El, Bridgeford EP, Ollila DW. Cutaneous melanoma: update on prevention, screening, diagnosis and treatment. Am Fam Physician. 2005;72(2):269-276.
Rose LC. Recognizing neoplastic skin lesions: a photo guide. Am Fam Physician. 1998;4:58.
Saraiya M, Glanz, K, Briss P, et al. Preventing skin cancer: findings of the task force on community preventative services on reducing exposure to ultraviolet light. MMWR. 2003;52(RR15):1-12.
Stulberg DL, Crandell B, Fawcett RS. Diagnosis and treatment of basal cell and squamous cell carcinomas. Am Fam Physician. 2004;70:1481-1488.
