Pigmented Lesions
Pigmented lesions are very common. The more common lesions are benign, but the physician must accurately rule out a malignant lesion or biopsy the lesion for definitive diagnosis. Nevi, seborrheic keratoses, and dermatofibromas are common benign lesions that often require evaluation by a physician. Dermatofibromas have a positive “dimple sign”; that is, when squeezed between two fingers, this firm subcutaneous pink, gray, or brown lesion puckers down into the skin.
Differential Diagnosis
-
Benign mole (nevus)
–Junctional (flat, pigmented), compound (raised, pigmented), and dermal (raised, usually not pigmented) -
Seborrheic keratosis
–Very common and benign
–Pink to dark brown, appear “stuck on” skin,
usually waxy and rough
-
Freckle (also known as ephilides)
-
Solar lentigo (“liver spot” or “sunspot”)
–Very common on the face and hands
–Light to dark brown macules, up to 2 cm
–If more than one color/abnormal borders,
consider diagnosis of lentigo maligna melanoma
- Dermatofibroma
–Firm, nodular, asymptomatic or slightly pruritic, often hyperpigmented lesion, most often on the lower extremities
–Dimples when pinched
–May result from minor trauma such as a scratch or insect bite
-
Dysplastic nevus
–“ABCD” changes: Asymmetry, Borders (irregular, jagged, streaked or “faded” edges), Color (more than one color; gray or black pigment or loss of pigment within the borders of a lesion), and Diameter (consider biopsy if >5 mm in diameter)
-
Blue nevus
–Usually benign
–Deep dermal pigmentation gives blue color -
Malignant melanoma
–Look for “ABCD” changes (see above)
–Superficial spreading type most common
–Acral lentiginous, nodular, and lentigo
maligna are other subtypes -
Café au lait macule
–Light brown, present at birth/toddlerhood
–Consider neurofibromatosis if five or more
café au lait and axillary freckling
-
Less common lesions include Spitz nevus (tan/pink, more common in children), nevus spilus, pigmented actinic keratosis, pigmented basal cell carcinoma, Becker's nevus [acquired in childhood or teens , usually large (>8 cm) and near shoulder], and Mongolian spot (benign, blue-gray, sacral area, congenital; fade/resolve in 1–2 years)
Workup and Diagnosis
- History and physical exam
–Note changes in the appearance of the lesion, pruritis, increase in size, or frequent bleeding/irritation
–Moles newly acquired after the age of 40 should be closely examined for dysplasia/malignancy
–Note family history of malignant melanoma and personal history of skin cancer or abnormal moles removed in the past
–Patients with light skin and blue eyes have a higher risk of abnormal moles and malignant melanoma
-
When in doubt, it is wise to perform a biopsy
–Shave biopsy is adequate for suspected actinic keratoses or seborrheic keratoses
–Deep scoop shave biopsy, excisional biopsy, or punch biopsy are indicated if dysplastic nevus or melanoma are considered, to sample the entire depth of the lesion
-
Referral to a dermatologist or plastic surgeon should be considered if an appropriate differential diagnosis cannot be made or if melanoma is being considered
Treatment
-
Sunscreen is indicated in all patients to prevent malignant and nonmalignant sun-induced lesions
-
Pigmented actinic keratoses and seborrheic keratoses can be successfully removed with topical cryotherapy
-
Solar lentigines and freckles can be treated with reassurance, or they can be removed with lasers and intense pulse light sources
–Solar lentigines may be lightened by topical
hydroquinones and retinoids
-
Patients with dysplastic nevi or prior malignant melanoma require at least annual full skin exams and close follow up of their nevi with body mapping if possible
Book Source Details
- Book Title: In a Page: Signs and Symptoms
- Author(s): Scott Kahan, Ellen G. Smith
- Year of Publication: 2004
- Copyright Details: In a Page: Signs and Symptoms, Copyright © 2004 Lippincott Williams & Wilkins.
Other Book Chapters Related to Hyperpigmentation
Read excerpts from these other book chapters related to Hyperpigmentation:
Copyright Details: In a Page: Signs and Symptoms, Copyright © 2008 Williams & Wilkins.
More About Causes of Hyperpigmentation
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More About This Book:
Title: In a Page: Signs and Symptoms
Authors: Scott Kahan, Ellen G. Smith
Publisher: Lippincott Williams & Wilkins
Copyright: 2004
ISBN: 1-4051-0368-X
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» Next page: Skin Pigmentation (Decreased) (In a Page: Signs and Symptoms)
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