What is the approach to managing a 2.3 mm thick skin Squamous Cell Carcinoma (SCC) with no apparent connection to the epidermis?

Management of Cutaneous Squamous Cell Carcinoma Without Epidermal Connection

Wide local excision with a 2-cm margin is the recommended treatment for a 2.3 mm thick squamous cell carcinoma (SCC) at the left temple, even when there is no apparent connection to the epidermis. 1

Understanding the Unusual Presentation

• SCCs typically present as indurated nodular keratinizing or crusted tumors that may ulcerate, but can occasionally present with unusual clinical features including no apparent connection to the epidermis 1, 2
• Unusual presentations of SCC can lead to delayed diagnosis and potentially worse outcomes, especially when the clinical appearance is misleading 2
• Any suspicious lesion that is palpable despite normal-appearing overlying skin warrants tissue sampling for definitive diagnosis 2

Risk Assessment

• A 2.3 mm thick SCC is considered intermediate risk, as tumors >4 mm in depth have significantly higher metastatic potential (45.7% vs 6.7% for tumors <4 mm) 1
• Location on the temple (head and neck region) is a higher risk factor for recurrence and metastasis 3
• The lack of epidermal connection is unusual and may represent an aggressive variant, requiring careful evaluation 4

Diagnostic Approach

• Complete excisional biopsy with histopathological evaluation is essential to:
  • Confirm the diagnosis and rule out other entities 1
  • Determine the depth of invasion, differentiation, and presence of perineural or vascular invasion 1
  • Evaluate for aggressive histologic subtypes (such as spindle cell variants) 4

Treatment Algorithm

1. Surgical Management (Primary Approach)

• Wide local excision with a 2-cm margin is the treatment of choice 1
• Consider the following during surgical planning:
  • Use marker sutures for specimen orientation 1
  • Mount the specimen appropriately for histopathological evaluation 1
  • Ensure histopathological evaluation determines lateral and deep margin clearance 1

2. Consider Mohs Micrographic Surgery

• May be appropriate when:
  • The tumor borders are difficult to define clinically 1
  • Tissue preservation is important for functional or aesthetic reasons 1, 5
• Note: Interpretation of frozen sections may be challenging in unusual SCC presentations 1

3. Regional Lymph Node Evaluation

• Perform clinical examination of regional lymph nodes 1
• If lymph nodes are palpable, obtain ultrasound-guided fine needle aspiration (FNA) 1
• Consider sentinel lymph node biopsy for high-risk features 1

Follow-up and Surveillance

• Regular follow-up examinations every 3-6 months for the first 2 years 1
• Evaluate for:
  • Local recurrence at the primary site 1
  • Regional lymph node involvement 1
  • Distant metastases in high-risk cases 1

Special Considerations for This Case

• The unusual presentation without epidermal connection requires careful histopathological evaluation to rule out aggressive variants like spindle cell SCC 4
• The 2.3 mm thickness places this tumor at intermediate risk, but the unusual growth pattern may suggest more aggressive behavior 1, 3
• If the tumor is near major blood vessels or nerves on the temple, imaging (MRI preferred) should be considered to assess the extent of invasion 1

Pitfalls to Avoid

• Don't mistake the normal-appearing epidermis for benign disease; the palpable mass requires thorough evaluation 2
• Don't underestimate the risk of metastasis based solely on tumor thickness; unusual growth patterns may indicate more aggressive behavior 3, 4
• Don't delay definitive surgical treatment, as SCC can progress to invasive disease with metastatic potential 6