Approach to skin and soft tissue lesions: Clinical sciences

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Introduction0:00–0:30

Skin and soft tissue lesions are dermatological abnormalities that look different from the surrounding skin in terms of color, size, or texture.
Most skin and soft tissue lesions are benign. However, some can be malignant or premalignant, so it's important to have a high clinical suspicion for any patient presenting with a new lesion.
Alright, your first step in evaluating a patient who presents with a skin or soft tissue lesion is to obtain a focused history and physical exam to help differentiate between a benign or a malignant lesion.

Benign lesions0:30–1:02

If, on history, the patient reports a slow growing asymptomatic lesion with minimal changes over time that doesn’t bleed easily, and a physical exam reveals that it’s symmetrical in color, shape, and structure, consider benign lesions.Now, let's dive into our first diagnosis, a benign vascular lesion.

Benign vascular lesions 1:02–2:11

Patients often report a mass or a lump that had an early onset in the first few months of life. They might have associated congenital syndromes like Sturge-Weber Syndrome.
On examination, you might find a salmon-colored patch, port-wine stain, strawberry or bright cherry red dome-shaped papules or macules that are blanchable when you press on them.
These lesions are usually located on the trunk, face, or upper extremities. If these are your findings, you are dealing with a benign vascular lesion.
Examples of benign vascular lesions include hemangioma, arteriovenous malformations, or pyogenic granuloma. Most vascular lesions tend to decrease in size as the patient gets older, so they usually don’t need any treatment.
If there are aesthetic concerns, you can offer topical agents like timolol, silver nitrate, or in some cases laser ablation or surgical excision.Alright, let's talk about another group of benign lesions: cysts and lipomas.

Epidermoid/dermoid cyst or lipoma2:11–4:05

History will reveal solitary, or multiple, slow growing lesions. Moving on to the physical exam.Skin cysts are divided into two types: epidermoid or dermoid.
Epidermoid cysts are sebaceous cysts that originate from hair follicles. They’re usually filled with keratin, so they look like firm, whitish nodules with a central punctum.
On the other hand, dermoid cysts form from entrapped ectodermal embryonic tissue, and may contain elements like hair follicles, sweat glands, and even teeth.
These are often congenital and present early in life. On exam, they tend to be slightly larger in size and deeper in the skin than epidermal cysts, and do not have a punctum.
Lastly, lipomas are fatty tumors typically in the subcutaneous space. These are soft, rubbery, round, mobile masses often located on the head, neck, shoulders, and back.
If these are your findings, you are dealing with a skin cyst or lipoma. Keep in mind that most of these lesions are asymptomatic, so they don’t need treatment.
However, surgical excision can be offered if they grow in size and cause mass effect.Here's a clinical pearl! Dermatofibroma is another rare, benign skin mass presenting as firm, pigmented bumps on the skin that might exhibit a dimple sign when pressure is applied.
These develop from neural mesenchymal cells and are associated with neurofibromatosis NF1 mutation. In some cases, it can arise from a reactive process after trauma like an insect bite.
Our next benign lesion is warts. Warts are common lesions caused by infection with the human papillomavirus, or HPV.

Wart4:05–4:51

In particular, HPV types 6 and 11 are known to cause warts, including anogenital warts. Patients typically report a small skin mass or lump that’s often asymptomatic, but in some cases can cause mild pain or itching.
Exam generally reveals a fleshy or skin-colored plaque or papule with a rough surface. They can be flat or have a cauliflower-like appearance, and are often located on elbows, knees, fingers, or palms.
If you see these findings, you are likely dealing with a wart! Let's now explore another benign skin lesion called acrochordon, also commonly referred to as a skin tag.

Acrochordon4:51–5:27

Patients with skin tags may present with small, discolored outgrowths that are generally painless, but some patients may experience discomfort from irritation due to friction with clothing or jewelry.
Upon examination, you’ll observe papillomatous or pedunculated outgrowths. They can have the same flesh color as the surrounding skin or you might observe hyperpigmentation.
If these are your findings, diagnose acrochordon.Next, we have nevi. These benign pigmented lesions arise from clusters of melanocytes, and can be congenital or acquired.

Nevus5:27–7:21

Nevi are typically slow growing and asymptomatic. Although nevi can vary in appearance, most are small, flat, round or oval macules; they’re symmetric in shape and monochromatic.
In terms of color, they’re most often tan or brown, but some can be flesh colored. Here’s a clinical pearl!
There are several different types of nevi, including melanocytic, atypical, halo, blue and Spitz nevi. Acquired melanocytic nevi are most common and represent moles and freckles.
Atypical nevi are dysplastic skin tumors arising from irregular nests of melanocytes. These are associated with increased risk of melanoma.
Halo nevi are commonly seen in children with personal or family history of vitiligo. These look like a mole with a circumferential area of depigmentation representing a halo.
Blue nevi occur from dendritic dermal melanocytes that produce the blue hue and are associated with genetic mutations. Lastly, Spitz nevi arise from spindle and epithelioid cells within the skin and have a starburst shape.
Because nevi can appear similarly to melanoma, you should always perform a thorough examination using the ABCDE criteria.
These criteria look for red flags, and stand for asymmetry, border irregularity, color variegation, diameter larger than 6 mm, and evolving over time.
Now that we’ve reviewed the benign lesions, let's go back and talk about malignant ones. Malignant skin and soft tissue lesions typically have a history of rapid changes in shape, color, structure or texture over a short period of time.

Malignant lesions7:21–7:53

These lesions can bleed easily or have ulceration. Additionally, patients can have a history of cancer.
These features should lead you to consider a malignant lesion.Let's start with squamous cell carcinoma, or SCC. Your patient may report a non-healing open lesion.

Squamous cell carcinoma7:53–8:58

Risk factors include exposure to sun or radiation, HPV, chemical exposure, a previous burn or scar, and immunosuppression.
On examination, you’ll typically see a raised nodule with irregular borders, and a rough scaly surface, as well as ulceration and potentially bleeding.
These findings are indicative of SCC. Next, obtain a biopsy; if it shows atypical squamous epithelial cells infiltrating the dermis, the diagnosis of squamous cell carcinoma is confirmed!Here's a clinical pearl!
A thin, eczematous plaque may indicate Bowen disease, meaning SCC in situ. Keratoacanthoma is a variant of SCC with a rapidly growing nodule and keratotic core.Alright, next is basal cell carcinoma, or BCC.

Basal cell carcinoma8:58–9:51

This is the most common type of malignant skin lesion. Patients may report a slow-growing lesion that doesn’t seem to heal.
Risk factors include sun exposure, fair skin, and immunosuppression. On examination, you’ll find a raised nodule that is shiny, waxy, translucent, or scar-like, sometimes with central ulceration.
BCC can also appear as a pink, pearly papule with overlying telangiectasia, and rolled or elevated borders. If you notice any of these findings, the next step is to obtain a biopsy.
If it shows infiltrating nodules of basal cells with peripheral palisading or clefting, you can confirm your diagnosis.Our next malignant skin lesion is melanoma.

Melanoma9:51–11:10

It can be discovered incidentally, or patients may report a new or changing mole. History may reveal exposure to sun, ultraviolet radiation, HPV, or chemical exposure.
Some patients may have a large congenital nevi; or family history of melanoma. During examination using the ABCDE criteria, you may notice irregularly discolored, nodular, pigmented lesions, sometimes with ulceration, bleeding, or itching.
Most lesions appear on the head, face, neck, or trunk. With these findings, consider melanoma and order a biopsy; if it shows nests of atypical melanocytes, the diagnosis of melanoma is confirmed.Here's a clinical pearl!
Another rare but aggressive skin differential to keep in mind is Merkel cell carcinoma. This cutaneous malignancy typically presents in sun-exposed areas as a painless, firm, bluish-red or flesh-colored nodule that can be rapidly-growing.
Most patients are older or immunosuppressed.Finally, let's discuss soft tissue sarcoma. Examples include liposarcoma, synovial sarcoma, leiomyosarcoma, rhabdomyosarcoma, fibrosarcoma, and angiosarcoma.

Soft tissue sarcoma11:10–13:02

Now, this type of cancer may present with an irregularly-shaped lesion, rapid growth, pain, a family history of sarcomas, radiation exposure, and some can be associated with an HIV infection.Exam might reveal an irregular border or margin, hyperpigmentation, ulceration, bleeding, or itching in the head, neck, or trunk area.
If these findings are present, you should consider the possibility of soft tissue sarcoma and proceed to obtain a biopsy.
If the biopsy results reveal characteristics like spindle-shaped atypical cells, you can confirm the diagnosis of soft tissue sarcoma.
Here's a clinical pearl! Kaposi sarcoma is an angioproliferative disorder characterized by atypical spindle cells arranged in slit-like vascular spaces, and is caused by infection with human herpesvirus 8.
Kaposi sarcoma is classified into four types based on the clinical circumstances in which it develops. First, the classic type typically presents in middle or old age.
Then, the iatrogenic type is associated with immunosuppressive drug therapy, typically seen in renal allograft recipients; while the epidemic type is associated with AIDS.
Lastly, the endemic type was described in Sub-Saharan African populations prior to the AIDS epidemic.Alright, as a quick recap… Skin and soft tissue lesions can be benign or malignant.

Review13:02–13:43

Common benign lesions include vascular lesions, cysts, lipomas, warts, skin tags, and nevi. These are usually asymptomatic, progress slowly, and don’t require further testing or intervention.
Malignant lesions include squamous cell carcinoma, basal cell carcinoma, melanoma, and soft tissue sarcoma. These often display rapid evolution with irregular or atypical features, needing a biopsy to confirm the diagnosis,