63-Year-Old Female With Growth on Scalp

Published on June 30, 2026

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Differential Diagnosis

• Keratoacanthoma
• Actinic keratoses
• Superficial basal cell carcinoma
• Seborrheic keratosis
• Cutaneous squamous cell carcinoma
• Psoriasis

Diagnosis

The correct diagnosis is cutaneous squamous cell carcinoma in situ (cSCC), or Bowen disease. Occupational risks for cutaneous squamous cell carcinoma are primarily driven by chronic, long-term exposure to sun-related ultraviolet radiation (UVR) and specific chemical carcinogens. cSCC can develop on any surface of the skin, but sun-exposed sites are the most common locations. Involvement of other areas, particularly the lower legs and anogenital regions, is more common in people with darkly pigmented skin.

cSCC in situ lesions tend to grow slowly, enlarging over the course of months or years. Although clinical findings may strongly suggest a diagnosis of cSCC, histopathologic examination is necessary to confirm the diagnosis and determine factors which are important for tumor staging and prognosis.

What to Look For

• Bowen disease typically presents as an erythematous, well-demarcated, scaly patch.
• Lesions can be skin colored or hypopigmented, particularly in individuals with darkly pigmented skin.
• Unlike the inflammatory disorders that may resemble cutaneous squamous cell carcinoma in situ, such as psoriasis or chronic eczema, cSCC in situ lesions are usually asymptomatic.
• Full skin exam: If there is concern for malignancy, patients should be given a full body skin examination that includes palpation of regional lymph nodes. 

Pearls For Urgent Care Management

• Shave, punch, or excisional biopsies may be used for diagnosis. Biopsies that extend at least into the mid-reticular dermis are preferred to allow for adequate evaluation of invasive disease.
• Prompt referral to dermatology: Surgical excision (including Mohs surgical approaches depending on the location) is the preferred treatment for cutaneous squamous cell carcinoma.
• Patients with a small, isolated lesion of Bowen disease can be treated with surgical excision, topical fluorouracil, or imiquimod. Large lesions (>3cm) may also be treated with photodynamic therapy, if available.

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