Understanding the Zebras of Wound Care: An Overview of Atypical Wounds

Elizabeth Ansert, DPM, MBA, MA; Anthony Tickner, DPM, FACCWS, FAPWCA, FAPWH; Donald Cohen, DPM; Weldon Murry, DPM; Samuel Gorelik, DPM


Wounds. 2022;34(5):124-134. 

In This Article

Neoplastic Ulcers

Basal Cell Carcinoma

Basal cell carcinoma (BCC) is a skin cancer that originates from the basal layer of the epidermis. Although BCCs are termed carcinoma, they are typically low in metastatic potential. However, they are locally invasive and relatively aggressive to the surrounding tissue. Basal cell carcinoma is common among White people and is rarely found in darker-skinned people. The lifetime risk among Caucasians for the development of BCC is approximately 30%.[60] It occurs more often in men than in women and is strongly associated with sunlight, with approximately 70% of BCCs occurring on the face.[60] Those who live closer to the equator are twice as likely to have a diagnosis of BCC than those who live farther from the equator. Smoking is associated with increased risk of BCC.[60–63]

Basal cell carcinoma typically arises from ultraviolet radiation-induced carcinogens. Several mutations in proto-oncogenes and tumor suppressors have been identified as risk factors for BCC. It has been suggested that hyperactivity of the hedgehog protein family leads to the development of BCC.[64]

Fifty percent to 80% of BCCs are the nodular type.[65] These present as flesh-colored or pink papules (Figure 12). It is characterized by a pearly appearance, with telangiectasias present within the papule. The periphery is often more raised than the center and is characterized as "rolled." Fifteen percent of BCCs are superficial; these scaly, non-firm BCCs occur most commonly on the trunk.[65] They are usually asymptomatic and can grow to several centimeters in diameter if left untreated.

Figure 12.

Basal cell carcinoma with pearly borders to the anterior shin.

Basal cell carcinoma is usually diagnosed based on clinical examination and biopsy. Shave, punch, or excisional biopsy may be used in the diagnosis of BCC. Treatment typically consists of excision of the lesion. Prevention is critical to the overall treatment plan. Sun protection is estimated to reduce the chance of BCC by approximately 80%.[66] The use of other topical treatments, such as topical fluorouracil and the use of nonsteroidal anti-inflammatory drugs, has also decreased the risk of BCC.[67,68]

Squamous Cell Carcinoma

Cutaneous SCC arises from epidermal keratinocytes and is a malignant tumor. It often presents as cutaneous lesions, including papules, plaques, and nodules; all these presentations can be smooth, hyperkeratotic, or ulcerative. It can occur on any skin surface, including the oral mucosa. Squamous cell carcinoma most commonly arises in fair-skinned individuals and in anatomic areas with high sun exposure. However, in dark-skinned populations, the most common anatomic locations are the areas of the skin that are not exposed to the sun.[69,70]

Invasive cutaneous SCCs are well-differentiated indurated or hyperkeratotic papules or nodules. They measure 0.5 cm to 1.5 cm in diameter and may present as an ulceration (Figure 13). Poorly differentiated tumors typically involve ulceration, bleeding, and necrosis and are mostly asymptomatic. Both SCC and BCC can arise from metastatic implantation. Other variants of SCC are keratoacanthoma, verrucous carcinoma, and lymphoepithelioma-like carcinoma of the skin.[71–73] Marjolin ulcer is a variant of SCC that typically forms in previously traumatized, chronically inflamed, or scarred skin.[74]

Figure 13.

Chronic nonhealing ulceration to the heel measuring about 15cm×15cm. Squamous cell carcinoma was confirmed on biopsy.

A histopathologic examination is crucial to confirm the diagnosis. A shave, punch, or excisional biopsy can be performed. Biopsies should extend into or through the midreticular dermis to determine the level of invasiveness.[75] Until a diagnosis is confirmed, disorders such as nummular eczema, psoriasis, PG, and venous stasis ulceration cannot be excluded. Typically, management consists of surgical excision of the lesion, but some topical medications, such as 5-fluorouracil, imiquimod, and ingenol mebutate, have been used in the management of lesions with minimal scarring risk.[76] Laser therapy and cryotherapy are also effective in the management of superficial lesions.[75] Radiation therapy is used in patients who cannot undergo surgical excision of the lesions.[76]


Although the severity of BCC and SCC varies from case to case, the most serious form of skin cancer is melanoma (Figure 14). Patients find most melanomas on their own out of concern for discoloration or odd-looking blemishes. The incidence of melanoma increases with age, and the prognosis is based on timely diagnosis, management, and extent of invasiveness.

Figure 14.

Patient presented with an abnormal lesion that was excised for pathological analysis. The analysis was positive for noninvasive melanoma.

The 4 major subtypes of melanoma are superficial spreading melanoma (SSM), nodular melanoma (NM), lentigo maligna melanoma (LMM), and acral lentiginous melanoma. Melanomas that spread into the dermis are considered to have metastatic potential. The metastatic likelihood of melanomas is often predicted based on Breslow depth, that is, the thickness of the tumor measured from the epidermal granular cell layer to the deepest part of malignant cells into the dermis or fat.[77]

The SSM is the most common type, accounting for nearly 70% of all melanomas.[78] These melanomas measure less than 1 mm in depth and are thin, and most of them are curable. The SSMs are often associated with an already existing nevus. They are typically multicolored macules or plaques with an irregular border. Nodular melanoma, the second most common type, accounts for approximately 15% of all melanomas and appears as dark pigmented pedunculated papules.[78] Unlike SSM, NM is uniform in color with symmetrical borders. The NM subtype is also relatively small, but it is not diagnosed until it is well over 2 mm in depth because of the lack of ill appearance. The LMM lesions are typically associated with sun-damaged skin and occur in older individuals. They typically begin as a tan macule. As the macule enlarges, it becomes darker with different colors.

Acral lentiginous melanoma accounts for less than 5% of melanomas.[79] This type typically occurs in darker-skinned individuals on the palms, soles, or underneath the nails. The acral lentiginous subtype may manifest with raised areas with ulceration and bleeding. This presentation is indicative of a deeper invasion of the dermis, and it is particularly important to foot and ankle surgeons because this subtype can appear to be a benign lesion such as a callus, wart, fungus, or ingrown nail, or even a nonhealing ulceration.[80,81]

Treatment of melanoma consists of surgical excision with a wide margin. Most melanomas have a very low threshold for referral to a dermatologist. Suspicious lesions should be examined every 3 months after the first patient visit. Any variation in symmetry, borders, color, depth, or edges warrants biopsy and referral.[81]