Diagnosing on the Spot: A Guide to Solitary Lesions

This blog post has been adapted from a VisualDx webinar presented by Azeen Sadeghian, MD, FAAD on solitary lesions and what to look for during a skin exam. This content is geared toward non-dermatologist clinicians.

Below is a brief overview of lesion you are likely to see during a skin exam, some mimickers, and what you can’t miss.

For those who are just beginning to learn about skin lesions, we recommend LearnDerm, a self-paced review of morphology and more.

The Exam

When you’re seeing a patient with a solitary lesion, begin with the symptoms. Does it itch? Does it bleed? Where is it located? Does it appear on UV-exposed skin or in a private area? Is it in the nail bed or scalp? How long as has it been there? If the spot hasn’t significantly changed in decades, then it is probably ok.

Noting the patient’s skin phototype is important: lighter skin is predisposed to UV damage due to lack of melanin and lesions in darker skin types may be hard to distinguish. However, note that anyone of any skin color can potentially develop skin cancer.

After noting the skin color, palpate the spot. Stretch and move the skin to see how the lesion behaves. Shine a light at an angle to detect any difference in texture. Buff the skin with gauze, particularly if you think it’s scaly and it will erode easily.

We can be biased by the appearance of a lesion and our own knowledge. It is easy to misdiagnose skin lesions. We need to be aware that it is easy to make diagnostic errors and that mistakes can harm patients.

Warning Signs

The following medical conditions should prompt further consideration prior to diagnosing:

• Immunosuppression due to medication, organ transplant, etc.
• Genetic disorders or cancer disorders
• Scarring skin disorders
• History of radiation therapy to affected site

Other at-risk populations include those with a history of chronic UV exposure, such as history of blistering sunburn, occupational UV exposure, and past or current tanning bed use.

Benign or Not?

Here are some clues that you should suspect a benign lesion based on history:

• Symptomatic
• Changing in size, shape, or color
• Bleeding
• Not healing
• Not responding to appropriate treatment

Categorizing Common Solitary Lesions

To keep this simple and easy to learn this first time, we’ll be broadly overcategorizing some common lesions based off their stereotypical appearance. This is not a comprehensive list, and lesions may present in various ways, present in colors different than these categories, or may technically fit into other categories.

The Brown Lesions: Lentigines and Nevi

Lentigo simplex

• Common benign, hyperpigmented macule
• Can be found anywhere on the body
• Can occur early in life and are not associated with sun exposure
• Asymptomatic, well-circumscribed, symmetric, homogeneous, brown macules <5 mm in size
• May be single or multiple, may evolve into junctional nevi

Solar lentigo (aka senile lentigo, age spot, or liver spot)

• Found on sun-exposed sites
• Usually seen in older patients

Common acquired nevus

• Subcategories include junctional, dermal, and compound nevi
• Benign and occur in all skin types
• Arise during childhood, adolescence, early adulthood
• Well-circumscribed, can be flesh-colored, pink, brown, or blue

Other nevus variants:

• Congenital nevus
• Blue nevus
• Atypical nevus
  • Irregular clinically
  • If biopsied and shows mild, moderate, or severe dysplasia then it is considered dysplastic nevus
  • Needs tailored monitoring and treatment

Warty Lesions: Seborrheic Keratoses and Verruca

Seborrheic keratosis

• Common, benign growth in adulthood (typically later in adulthood), can affect any skin type
• Waxy (warty) “stuck-on”-appearing papules and plaques with well-defined borders
• Various colors
• May start out as a flat seborrheic keratosis
• Asymptomatic but can become irritated

Verruca vulgaris

• Common wart
• HPV, infectious etiology
• Can be solitary or multiple.
• Verrucous, hyperkeratotic, black or red dots within the lesion are thrombosed vessels and characteristic of common warts
• Benign, self-limited; therapy indicated if patient is immunocompromised, lesion is found in a sensitive location, or there is a risk of autoinoculation
• Biopsy indicated if atypical or not resolving

Verruca plana

• Flat warts, not generally “warty” in appearance, and tend to be multiple
• Caused by autoinoculation
• Slightly elevated, small, flat-topped, papules
• Can range in color from pink, skin-colored, or hyperpigmented

Red Lesions: Angiomas and Pyogenic Granulomas

Angioma aka cherry angioma / hemangioma

• Most common acquired benign vascular proliferation; thin-walled, dilated capillaries
• Seen in adulthood
• Small red or violaceous papules
• They increase in number and incidence with age
• Benign, asymptomatic, can become irritated or bleed

Lobular capillary hemangioma

• Also known as pyogenic granuloma
• Rapidly growing, benign vascular proliferations of the skin or mucous membranes
• Majority are without cause; possible association with injury or hormones (such as during pregnancy)
• Seen on trunk, head, neck, hands, and fingers
• Gingival/lip involvement most often seen in pregnant women
• Often painless but ulcerate and bleed easily
• More common in children and young adults but can occur at any age

The Bumps and Lumps: Cysts and Lipomas

Epidermoid cyst aka epidermal inclusion cyst

• Cyst wall is squamous epithelium (think skin), contents are macerated keratin and lipid-rich debris
• Commonly found on face, trunk, extremities, and the genitals at any age
• More common in men
• Firm, skin-colored nodule with or without punctum
• May or may not have malodorous material that can be expressed
• May have history of rupture

Digital mucous cyst

• Myxoid cyst, commonly distal interphalangeal (DIP) joint of digit
• Skin-colored or translucent papule overlying DIP, with or without nail groove

Lipoma

• Benign fatty tumor
• Usually asymptomatic
• Soft, mobile, subcutaneous, usually with no overlying skin changes
• Can occur anywhere but usually on fatty sites
• Can be single or multiple

Skin Cancers

Actinic keratosis

• Technically not cancer but considered a precancerous growth
• Precursor to squamous cell carcinoma (SCC), though not all actinic keratoses turn into SCC
• Risk factor in patient for developing non-melanoma skin cancer
• Usually seen in sun-exposed areas and older patients
• May or may not be symptomatic
• Erythematous scaling papule(s), can sometimes be pigmented
• Various treatments, cryodestruction most common treatment for solitary lesions
• Encourage skin checks and photoprotection

Squamous cell carcinoma

• Second most common form of skin cancer
• Can occur anywhere
• Risk factors include UV/photoexposure, radiation, immunosuppression, HPV, chemical exposure, fair skin, chronic wounds or scars, etc.
• Has potential for invasion, metastases.
• Monitor patients (lymph nodes, skin checks, etc.)
• Classic presentation: erythematous scaling plaque
• Other presentations: nodule, ulcer
• Erosions, ulcers, bleeding, symptoms, recurrence, duration are clues to consider biopsy
• Surgery is usually treatment of choice

Basal cell carcinoma

• Most common skin cancer
• Various subtypes
• Rarely metastasizes, locally destructive
• Risk factors include UVR, fair skin types
• Most common presentation: pink pearly papule or plaque with telangiectasia
• Other presentations include pigmented, ulcerated, others
• Treatment includes surgery, destructive methods, or sometimes other modalities

Melanoma

• Aggressive tumor of melanocytes,
• Can metastasize and can occur anywhere and in people of any race
• Multiple subtypes
• Risk factors: Family or patient history of melanoma, history of severe or blistering sunburns, a changing mole, a giant congenital nevus (greater than 20 cm), older age, lighter skin phototype, multiple atypical nevi, tanning bed use
• Remember the ABCDEs, ugly duckling, and be suspicious of any new, symptomatic, or changing mole
• Excisional biopsy; excision therapy with wide margins; lymph node exam/skin checks
• Certain indications for lymph node biopsy and imaging

Some Key Takeaways:

If benign:

• Always let your patient know to contact you if their lesion changes or becomes symptomatic so that you can re-evaluate

If malignancy is suspected then a biopsy is indicated:

• Use a dermatopathologist
• Read the entire report, not just top line
• Subtype is just as important as type of cancer
• Sometimes needs a re-biopsy due to biopsy limitations (ie, need larger/deeper biopsy or missed pathology)

Most skin cancers are treated and managed by dermatologists. This includes excisions.

If a skin cancer meets Mohs criteria (based off location or type of cancer), then it can be referred to a Mohs surgeon.

We hope this overview gives you some more confidence as you encounter solitary lesions during skin exams. Be sure to get on our mailing list at the bottom of this page to stay in the know about other Webinars. Registration details for our next webinar, Treating Acne With The Tetracycline Class of Antibiotics: A Review, can be found below. Please join us!