Squamous cell carcinoma (SCC) is the second most common type of skin cancer after basal cell carcinoma. This tumor, which originates from keratinocytes in the middle and upper layers of the epidermis, can follow a more aggressive course compared to basal cell carcinoma and carries metastatic potential. For this reason, early diagnosis and appropriate treatment are of vital importance.

What Is Squamous Cell Carcinoma?

Squamous cell carcinoma is a malignant neoplasm that develops from the flat epithelial cells of the skin. It generally appears in areas chronically exposed to sunlight. The face, backs of the hands, ears, lower lip, and bald scalp are among the most frequently affected regions. Unlike basal cell carcinoma, SCC has the capacity to spread to regional lymph nodes and distant organs.

Risk Factors and Precancerous Lesions

Chronic UV exposure is the primary risk factor. Fair skin type, advanced age, male sex, and immunosuppression significantly increase the risk. Organ transplant recipients face sixty to one hundred times greater risk of developing SCC compared to the general population.

Actinic keratosis is the best-known precancerous lesion for SCC. These rough, scaly lesions that appear on sun-exposed areas can, over time, transform into invasive SCC. Bowen's disease, known as SCC in situ, is a stage showing full-thickness epidermal dysplasia that has not yet invaded the dermis.

Chronic wounds, burn scars, radiodermatitis areas, and certain chronic inflammatory conditions can also provide a basis for the development of SCC. Human papillomavirus (HPV) infection is another factor that increases the risk of SCC, particularly in the genital and periungual regions.

Clinical Findings

Squamous cell carcinoma typically presents as a firm, keratotic-surfaced, reddish nodule or plaque. Ulceration, crusting, and bleeding may be observed on the lesion. Rapid growth, tenderness, and adherence to surrounding tissue are signs of aggressive behavior.

Lip SCC warrants particular attention. It may begin as a non-healing crack or sore on the lower lip, and its rate of metastasis is higher than other regions. Lesions on the ear and temple are also considered high-risk.

Diagnostic Process

In cases of clinical suspicion, dermoscopic evaluation is performed. On dermoscopy, white structureless areas, polymorphic vascular patterns, and keratin masses are findings suggestive of SCC. A definitive diagnosis is made by tissue biopsy. In the histopathological examination of the biopsy material, the degree of tumor differentiation, invasion depth, and presence of perineural invasion are evaluated from a prognostic standpoint.

For high-risk lesions, ultrasonography and, when necessary, advanced imaging methods are used for regional lymph node assessment. Sentinel lymph node biopsy may be applied in certain cases for staging purposes.

Current Treatment Protocols 2026

Surgical excision is the primary treatment modality. Appropriate surgical margins are determined according to the risk profile of the tumor. While four to six millimeter surgical margins are considered sufficient for low-risk tumors, wider margins or Mohs micrographic surgery are preferred for high-risk lesions.

Mohs surgery is considered the gold standard, particularly for facial lesions and high-risk tumors. This technique allows microscopic control of surgical margins, ensuring both complete tumor removal and maximum tissue preservation.

Radiotherapy may be used in patients for whom surgery is not feasible or as adjuvant treatment. In metastatic SCC, immunotherapy agents — particularly PD-1 inhibitors — have gained a significant place in treatment protocols in 2026. Cemiplimab and pembrolizumab are among the approved options for the treatment of advanced-stage SCC.

Prognosis and Follow-Up

In early-stage SCC, the five-year survival rate is quite high. However, the risk of recurrence and metastasis increases in tumors with high-risk features. Regular clinical follow-up after treatment, early detection of new lesion development, and educating patients about sun protection are integral parts of the treatment plan. Please contact us for pricing information regarding consultations and treatment options.

References

  1. Alam M, Ratner D. "Cutaneous squamous-cell carcinoma." N Engl J Med. 2001;344(13):975-983. [PubMed]
  2. Migden MR, et al. "PD-1 Blockade with Cemiplimab in Advanced Cutaneous Squamous-Cell Carcinoma." N Engl J Med. 2018;379(4):341-351. [PubMed]
  3. National Comprehensive Cancer Network (NCCN) -- Squamous Cell Skin Cancer Guidelines 2026. [NCCN]
  4. American Academy of Dermatology -- Squamous Cell Carcinoma. [AAD]

This article is for informational purposes only. Please consult a qualified physician for treatment decisions.