What are the typical presentation and appearance of squamous cell carcinoma (SCC) of the head in an older adult with a history of prolonged sun exposure, fair skin, and risk factors such as smoking or immunosuppression?

Squamous Cell Carcinoma of the Head: Clinical Presentation and Appearance

Primary Clinical Presentations

Cutaneous SCC of the head typically manifests in two distinct patterns: an indurated nodular keratinizing or crusted tumor that may ulcerate, or as a pure ulcerative lesion without keratinization. 1

Classic Nodular-Keratotic Form

• Indurated (firm) nodular growth with a raised, three-dimensional appearance rather than flat 1
• Thick adherent crust or scale formation (surface keratinization) that distinguishes it from inflammatory processes 1
• May progress to ulceration as the lesion advances 1
• The firmness of the base is a critical distinguishing feature from benign inflammatory conditions 1

Pure Ulcerative Form

• Presents as an ulcer without evidence of keratinization 1
• Often has raised or rolled edges 1
• May appear as a non-healing wound in patients with chronic skin damage 1

High-Risk Warning Signs Requiring Urgent Evaluation

In patients with chronic sun damage or wounds on the head, maintain high suspicion for these features:

• Non-healing lesion lasting ≥4 weeks (exceeds typical wound healing timeframe) 1
• Rapidly growing lesion with heaped-up appearance resembling exuberant granulation tissue 1
• Deep, punched-out ulcer with raised or rolled edges 1
• Hyperkeratotic area surrounded by a shoulder of raised skin 1
• Altered sensation suggesting perineural involvement 1

Patient Demographics and Risk Profile

Typical Patient Characteristics

• Peak incidence in the seventh decade of life 2
• Fair-skinned individuals with prolonged sun exposure history 2
• Head and neck location accounts for 29-54% of cases 2
• Slight female preponderance overall, though distribution patterns vary by anatomic site 2

High-Risk Patient Populations

• Immunosuppressed patients (transplant recipients, chronic immunosuppression) have significantly poorer prognosis and more aggressive disease behavior 2
• Smokers have increased risk, particularly for head and neck sites 3
• Patients with history of arsenic exposure may develop lesions even in sun-protected areas 2
• Patients with chronic wounds, scars, or burns on the head 4

Critical Diagnostic Pitfall to Avoid

Do not dismiss persistent crusted, ulcerated, or non-healing lesions as simple inflammatory conditions or chronic wounds. The presence of persistent crusting with ulceration in sun-exposed areas of the head in fair-skinned individuals, especially those over age 60, mandates biopsy to exclude SCC 1.

In immunosuppressed patients or those with chronic wounds, maintain an even lower threshold for tissue diagnosis, as SCC in these populations behaves more aggressively with higher metastatic potential 1, 2.

Anatomic Site-Specific Considerations for Head Lesions

Location Influences Prognosis

• SCC of the lip and ear carry higher metastatic potential compared to other sun-exposed head sites 2
• Periocular/pericanthal location is considered high-risk due to proximity to critical structures and potential for perineural invasion 4
• Scalp, ears, nose, cheeks, forehead, and perioral regions are common sites requiring careful evaluation 2

Size and Depth Characteristics

High-Risk Tumor Features

• Tumors >2 cm diameter are twice as likely to recur locally (15.2% vs 7.4%) and three times as likely to metastasize (30.3% vs 9.1%) 2
• Tumors >4 mm depth or extending to subcutaneous tissue have metastatic rate of 45.7% compared to 6.7% for thinner tumors 2
• Rapidly growing lesions indicate more aggressive behavior 2

Definitive Diagnosis

Always obtain histopathologic confirmation via biopsy before initiating treatment — clinical appearance alone is insufficient for definitive diagnosis 1, 2.

Preferred Biopsy Technique

• Punch biopsy is preferable to curette biopsy as it allows visualization of full thickness epidermis and dermis to establish whether invasive disease is present 2
• Dermoscopy may aid clinical diagnosis (showing glomerular vessels and scaling) but does not replace histologic confirmation 2

Essential Histologic Information

The pathology report must include 2:

• Pathological pattern and cell morphology
• Degree of differentiation (well vs poorly differentiated)
• Histological grade (Broders classification)
• Depth (thickness in mm)
• Level of dermal invasion (Clark's levels)
• Presence or absence of perineural, vascular, or lymphatic invasion (critical prognostic factors)

Associated Skin Cancer Risk

Patients presenting with SCC of the head have significantly elevated risk for additional skin cancers:

• 30-50% will have previous or subsequent non-melanoma skin cancer, mainly basal cell carcinoma 2
• Patients with ≥10 actinic keratoses have threefold higher risk of having history of SCC 2
• Full-body skin examination reveals skin cancer (BCC, SCC, or melanoma) in 4% of patients with multiple actinic keratoses 2