Approach to skin and soft tissue lesions: Clinical sciences

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. 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. 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. 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. 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. 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. 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.