Mole or Melanoma? Tell-Tale Signs in Benign Nevi and Malignant Melanoma: Slideshow

Patients are often oblivious to changes in their own moles that might indicate malignancy, and, as a result, many malignancies are discovered incidentally. The only way to halt the rapidly growing number of deaths from malignant melanoma is through early diagnosis and intervention. Everyone who sees patients should be exposed to as many visual examples of melanoma as possible. The following photographs of skin lesions ranging from normal nevi to invasive malignant melanoma were contributed by Theodore Scott, RN, MSN, FNP-C.

A congenital nevus is a proliferation of benign melanocytes that is either present at birth or develops shortly afterwards. Congenital nevi are usually classified by size: small (less than 1.5 cm in diameter), medium (larger than 1.5 cm and up to 20 cm) or giant (measuring 20 cm in diameter or larger).

This patient has a nevus spilus, a common benign melanocytic nevus with a speckled appearance. A nevus spilus can be macular or papular, exhibiting multiple smaller pigmented macules surrounding the central pigmentation. This lesion may be congenital or acquired and carries a small risk of malignant changes. It is also known as a speckled lentiginous nevus.

This benign congenital nevus shows a normal variation in color. Other colors often displayed by congenital nevi include tan to dark brown, flesh-colored to pink, and even blue-black. The frequency of malignant degeneration in small congenital nevi, like this one, is about 10%.

This congenital nevus, measuring about 3 cm, is papular (raised) with a slightly pebbled texture. The variations in brown color, which are normal, can change with maturity, and the nevus can grow hair. However, this nevus should be watched for changes that might suggest malignancy, such as an increase in size, changing colors, ulceration, bleeding, itching, or pain.

This is a dermal nevus with congenital features located on a patient's distal anterior thigh. The melanocyte cells of this dome-shaped nevus have descended into the dermis. Dermal nevi are often brown or black; this nevus is beginning to lighten, giving it a gray appearance. A faint area of depigmentation (halo) can be seen surrounding the nevus. Some dermal nevi are pedunculated with a soft, flabby, wrinkled surface.

This congenital nevus, located on the patient's back, was biopsied and found to be a category 1 superficial compound nevus. Compound nevi (a histologic diagnosis) often have features in common with malignant melanoma, such as asymmetry and poor circumscription. This nevus also has scattered darkly pigmented areas rather than a central darker area more typical of congenital nevi.

Category 1 = mild atypia
Category 2 = moderate atypia
Category 3 = severe atypia, melanoma in situ arising in a nevus

This congenital nevus, measuring approximately 5 mm, was located on the patient's upper chest. This is a junctional nevus, meaning that it is at the junction of the dermis and the epidermis. Junctional nevi have pigment regularity and are flat or slightly raised.

This category 1 compound nevus was located on the patient's upper back. Note the irregularity of the borders of this nevus and the asymmetry. A shave biopsy was performed for a histologic diagnosis, and it was found to be benign.

Another compound nevus, located on the midsternal area, exhibits irregular borders and asymmetry. However, this nevus is benign. In a compound nevus, melanocytes are found in both the dermis and the epidermis. In addition, the compound nevus can have both raised and flat areas.

This large compound nevus has mild to moderate atypia. These moles usually begin to appear during adolescence, most often on the back, chest, abdomen, buttocks, and scalp. Atypical nevi are often larger than 0.6 cm, have variegated coloration ranging from pink to brown, indistinct borders, and a textured surface. A central raised darker papule surrounded by a macule of lighter pigmentation gives this nevus a "fried-egg" appearance, as illustrated here. Atypical moles tend to be familial and have a higher rate of malignant transformation, so they must be closely monitored. This patient underwent a skin punch biopsy that revealed melanocytic atypia.

This focal area of darker pigmentation is known as solar lentigo, one of several benign conditions easily mistaken for melanoma. These small, 1- to 3-cm macules are usually round, light yellow to brown in color, and appear on chronically sun-exposed skin, such as the ear shown here. These macules can enlarge and eventually coalesce into patches. Solar lentigo (sometimes referred to as a "liver spot") is the most common benign sun-induced lesion of the skin.

This patient has a seborrheic keratosis on the nose. Seborrheic keratoses are the most common benign skin lesion in older individuals. Developing from a proliferation of epidermal cells, these growths occur more often in sun-exposed areas of the skin and have variable pigmentation (pinks to browns, occasionally dark brown or black). A reticulated type of seborrheic keratosis may develop from a solar lentigo. These lesions can grow larger, become irritated, crusty, and itch or bleed. They can also appear waxy, soft, and greasy. These lesions are sometimes called barnacles. In this patient, the lesion involved the skin and adipose tissue. It was diffusely pigmented, and no atypical melanocyte proliferation was identified after excisional biopsy.

These seborrheic keratoses were located on the patient's back. Although they can occur in younger individuals, seborrheic keratoses increase with age and are sometimes numerous. They can also run in families. Seborrheic keratoses usually begin as flat, brown, circumscribed macules and can increase in size and thickness, causing some patients to fear melanoma. When inflamed, these lesions can become red-brown in color. A seborrheic keratosis can have the appearance of something that is pasted or stuck on the skin surface.

Another pigmented seborrheic keratosis, illustrating the variety in coloration that these lesions may produce. The surface of a mature lesion can display multiple plugged follicles and have a dull or nonlustrous appearance (does not reflect light). More than 50% of seborrheic keratoses are located on the trunk, as shown here. In some patients, multiple seborrheic keratoses will align along with folds of skin. A shave biopsy can provide a histologic diagnosis.

A benign seborrheic keratosis located on the patient's neck, an area that receives sun exposure. Despite its black color, this seborrheic keratosis can clinically resemble melanoma. Distinguishing superficial seborrheic keratoses from lentigo maligna and pigmented actinic keratoses can be difficult. The surface of this lesion is not as lustrous as that of a melanocytic nevus. Seborrheic keratoses do not develop into malignant melanoma.

This is a pigmented nodular basal cell carcinoma, the most common variant of basal cell carcinoma. This growth, measuring approximately 8 mm, is located on the patient's shoulder and is well-defined with focal pigmentation. Basal cell carcinomas are slow growing, rarely metastasize, and have an excellent prognosis, although untreated tumors can be disfiguring. These lesions arise from pluripotential cells in the basal layer of the epidermis or outer root sheaths of follicular structure. They are far more common in light-skinned individuals and appear in adulthood, usually on the face, ears, scalp, neck, or upper trunk. These growths are easily irritated and may bleed when traumatized. The patient often has a history of chronic sun exposure.

Malignant melanoma in situ was found on this patient's shoulder. Melanoma is a malignancy of the pigment-producing melanocytes, a disease that has tripled among white individuals during the last 20 years. Features of melanoma evident in this slide include asymmetry, irregular borders, multiple shades of pigmentation, a blotchy appearance, an area of depigmentation, and an irregular surface texture. Melanoma in situ is confined to the epidermis, known as a level I in Clark's system of depth of penetration of melanomas. Clark levels are based on the layer of skin or tissue that is involved in the malignancy, a classification that is becoming outdated in favor of Breslow staging.

Clark Levels:

Level I -- no cells have penetrated the dermoepidermal junction
Level II -- some cells are found in the papillary dermis
Level III -- cells fill the papillary dermis
Level IV -- cells invade the reticular dermis
Level V -- cells invade into fat

A shave biopsy revealed this 7- to 8-mm asymmetrical growth to be melanoma in situ. "Melanoma in situ" implies that the melanoma is purely intraepidermal, and no neoplastic cells have penetrated the dermoepidermal junction. This melanoma displays different colors with focal areas of darker pigmentation. Generally, a lesion that grows to a size of 6 mm or greater suggests melanoma, although smaller melanomas are possible. The risk factors for melanoma include fair skin, having multiple sunburns as a child, having many moles (especially atypical nevi), use of tanning beds, and family history of melanoma in a first-degree relative.

This example of melanoma in situ occurred on the patient's shoulder. Features include markedly asymmetrical appearance, irregular borders, hypopigmentation, and a bumpy surface. The pinkish area indicates regression (an immune phenomenon whereby a portion of the cancer cells are destroyed and replaced by fibrosis). This lesion measured approximately 1.5 cm in diameter.

This large malignancy, measuring more than 1 cm, is asymmetrical with variegated coloring (and focal black areas) and irregular borders. Note that this tumor is located just above the area that would be covered by a bikini. The patient admitted to multiple sunburns as a child. This illustrates the importance of examining the entire body to identify melanomas.

Lentigo maligna melanoma is a subtype of invasive melanoma. Usually found on sun-exposed skin, lentigo maligna melanoma is a slow growing tumor and occurs most often in older adults. Legions are typically tan to brown, with varying colors; sometimes they appear to be a stain on the skin. This lentigo maligna melanoma on the patient's shoulder has a subtle appearance; the only abnormal signs to the naked eye are irregular borders, asymmetry, and variations in color. The lesion is a Clark Level II, with a Breslow depth of 0.4 mm, a measurement of the vertical depth of a tumor from the epidermis to the deepest melanoma cell. Breslow depth has prognostic significance, and a biopsy is required for determination.

Breslow depth of invasion (thickness) and approximate 5-year survival:

• < 1 mm, 95% to 100%
• 1-2 mm, 80% to 96%
• 2.1-4 mm, 60% to 75%
• > 4 mm, 50%

This is an invasive malignant melanoma that penetrates to a Breslow depth of 0.45 mm. A closer look at this tumor reveals that it is asymmetric with irregular borders, multiple small dots, and a faint rim of erythema. Fairly rapid development was also a factor in this case. In invasive melanoma, cancer cells have descended through the basement membrane into the dermis.

This melanoma, located on the patient's back, has a slightly irregular border and is also slightly asymmetrical. A brown macular and central black nodule are present, but there is no ulceration. It would be easy to bypass this melanoma as a melanocytic nevus if not examined closely, compared with other moles on the patient's body, and inquiring about the evolution of the lesion. This lesion is a Clark Level III, with a Breslow depth of invasion of 0.6 mm.

This example of invasive malignant melanoma is a Clark Level III, 0.6-mm Breslow level of invasion located on the patient's thigh. Clinical findings include size greater than 7 mm, several different shades of brown including a dark center, and an irregular border. No ulceration was present.

This nodular pigmented malignant melanoma measures 3.5 mm in thickness. This tumor is bluish-black in color, with a wide faint rim of erythema. Many melanomas grow radially first, and then vertically, but nodular melanoma has an early vertical growth phase. Nodules are more uniform in color and can ulcerate and bleed. Nodular melanoma is an aggressive tumor, twice as common in men as in women, and often occurs at younger ages.

This growth has all of the features suggestive of classic malignant melanoma: irregular borders, asymmetry, several different colors with black areas, chronic inflammation, and ulceration with bleeding and crusting. A trail of erythema can be visualized on one side. Biopsy revealed the histologic diagnosis to be invasive malignant melanoma

For More Information

Malignant Melanoma – eMedicine Dermatology
http://emedicine.medscape.com/article/1100753-overview

Malignant Melanoma – eMedicine Oncology
http://emedicine.medscape.com/article/280245-overview

Lentigo Maligna Melanoma – eMedicine Oncology
http://emedicine.medscape.com/article/279839-overview

Basal Cell Carcinoma – eMedicine Oncology
http://emedicine.medscape.com/article/276624-overview

Congenital Nevi – eMedicine Dermatology
http://emedicine.medscape.com/article/1118659-overview

National Cancer Institute – Melanoma
http://www.nci.nih.gov/cancertopics/types/
melanoma

The Skin Cancer Foundation
http://www.skincancer.org/melanoma/

Melanoma Research Foundation
http://www.melanoma.org/

American Cancer Society
http://www.cancer.org/docroot/CRI/content/
CRI_2_2_1X_What_is_melanoma_skin_
cancer_50.asp

Author Information

Theodore D. Scott, RN, MSN, FNP-C, DCNP
Southern California Permanente Medical Group, Department of Dermatology, San Marcos, California; Clinical Preceptor, Hahn School of Nursing and Health Science, University of San Diego, San Diego, California; Member at Large, Executive Committee
Nurse Practitioner Society of the Dermatology Nurses Association; Associate Editor, Journal of the Dermatology Nurses Association
Disclosure: Theodore D. Scott, RN, MSN, FNP-C, DCNP, has disclosed no relevant financial relationships.

Laura A. Stokowski, RN, MS
Staff Nurse, Inova Fairfax Hospital for Children, Falls Church, Virginia; Editor, Medscape Ask the Experts Advanced Practice Nurses
Disclosure: Laura A. Stokowski, RN, MS, has disclosed no relevant financial relationships.