Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) are the first and second most common types of skin cancer, respectively. Other significant skin lesions are actinic keratosis and melanoma. Actinic keratosis and basal cell carcinoma are easily excised and have a very good prognosis, while cSCC has a poor prognosis, especially if it invades the lymph nodes and adjacent vital structures. Actinic keratosis is the premalignant precursor for cSCC, and early treatment will save the patient morbidity. Extrinsic factors, such as ultraviolet light from sun exposure, are linked to cSCC, while intrinsic factors, such as the use of antioxidants, aspirin, and nonsteroidal anti-inflammatory drugs (NSAIDs),
are reported to reduce the risk of developing the disease.
A biopsy should be performed for any lesion suspected of being a cutaneous neoplasm. For invasive cSCC, surgical excision and Mohs micrographic surgery are the primary treatment options.
Signs and symptoms of cutaneous squamous cell carcinoma
Clinically, cSCC presents as a shallow ulcer with elevated margins, often covered by a plaque and usually located in a sun-exposed area. Typical surface changes may include scaling, deep ulceration, crusting, and cutaneous horn.
A less common presentation of cSCC includes a pink cutaneous nodule without overlying surface changes. Regional metastasis of head and neck cSCC may result in enlarged and palpable submandibular or cervical lymph nodes.
If cSCC invades the adjacent peripheral nerve, it causes numbness, pain, and muscle weakness. These may be some of the clinical signs of invasion other than palpable lymph nodes.
Diagnosis of cutaneous squamous cell carcinoma
Diagnostic workup of suspected cSCC will include computed tomography (CT) scanning to evaluate for soft tissue or bony invasion and lymph node metastasis. Magnetic resonance imaging (MRI) may be used to rule out invasion of neural or vital structures. Incisional or excisional biopsy are essential for definitive diagnosis. The choice of biopsy will depend on the size and location of the lesion.
Management of cutaneous squamous cell carcinoma
Treatment options include the following:
Surgical excision with clear margins, as verified by frozen sections
Mohs micrographic surgery for invasive cSCC in the facial region
Radiation therapy as an adjuvant to surgery, to provide improved locoregional control, or as primary therapy in patients who are unable to undergo surgical excision
Chemotherapy, such as treatment with oral 5-fluorouracil (5-FU) and epidermal growth factor receptor (EGFR) inhibitors, as adjuvant therapy for select highest-risk cases
Systemic chemotherapy for metastatic cSCC