Squamous Cell of Head and Neck

Pathology

Invasive Lesions

• low-grade SCCA are the most common
• high-grade SCCA are 5% of the SCCA
• basal cell arise from the skin of the lip but not the vermilion (but may invade it)
• melanoma

Superficial Lesions

• CIS
• Leukoplakia
• Hyperkeratosis
• Cheilitis

Benign

• hemangiomas
• fibromas
• cysts

Various Forms of SCCA

Eponyme for Squamous Cell Carcinoma

Marjolin's Ulcer

SCC winthin a burn scar

Verrucous Carcinoma

Low-grade SCCA, exophytic & often anogenital, oral, or on the plantar surface foot with little metastatic potential

Spindle Cell

> 40 yo in sun exposed areas

Keratocanthoma (KA)

• originates in the pilosebaceous glands and closely and pathologically resembles squamous cell carcinoma (SCC).
• KA is reddish papules rapidly progress crateriform ulceration or keratin plug.
• KA are recurrent after surgical excision or those in which resection would result in cosmetic deformity may benefit from RT 35/15fx to 56/28fx.

Carcinoma In Situ

Bowen’s disease

• Untreated, development of invasive carcinoma is possible but uncommon.
• Unlike actinic keratosis, Bowen’s disease involve epidermal appendages, particularly the hairfollicle.

Erythroplasia of Queyrat

is Bowen’s disease of glans penis or vulva.

Treatment

• Surgical excision is usually preferred; however, radiation therapy may be considered as an alternative.
• 45 to 50 Gy at 2.5 to 3.5 Gy per fraction commonly employed.
• Facial lesions require 56 Gy at 2.0 Gy per fraction for improved cosmesis.
• Radiation therapy may be contraindicated for lower extremity lesions, as chronic, nonhealing ulcers are reported

Pre-malignant

Actinic Keratosis

• scaly or crusty bump
• epidermal hyperplasia and cellular atypia

Tumor Recurrence^[2]

• Recurrent SCCA occurs in 15% of patients
• A minority of patients (27%) did not have an identifiable index lesion.
• most recurrent lesions are located within the lymphatic drainage of the parotid:

Local Recurrence and Metastasis

Influence of Tumor Variables on Local Recurrence and Metastasis of SCCA^[6],[7]

Factor	Local Recurrence	Metastasis	Comments
Size			size alone is not likely to be an independent factor for metastasis
2 cm	7.4%	9.1%
≥ 2 cm	15.2%	30.3%
Thickness/ Depth of invasion			> 4-5 mm likely to have high-rate (> 15%) of regional LN
< 4 mm	5.3%	6.7%
> 4 mm	17.2%	45.7%
Differentiation			associated with regional metastases
Well Differentiated	13.6%	9.2%
Poorly Differentiated (desmoplastic SCCA)	28.6%	32.9%
Site
Sun-exposed	7.9%	5.2%
Ear	18.7%	11.0%	high risk especially with cartilage invasion, deep invasion or poor differentiation
Lip			high-risk especially T3/T4
Scar Carcinoma	N/A	37.9%
Previous Treatment	23.3%	30.3%	higher incidence of nodal metastasis
Perineural Involvement	47.2%	47.3%	ENI recommended
Immunosupression	N/A	12.9%

Bibliography

1. O’Brien CJ. The parotid gland as a metastatic basin for cutaneous cancer. Arch Otolaryngol Head Neck Surg. 2005; 131:551-555.

2. Veness MJ, Palme CE, Morgan GJ. High-risk cutaneous squamous cell carcinoma of the head and neck: results from 266 treated patients with metastatic lymph node disease. Cancer. 2006 Jun 1;106(11):2389-96. PMID: 16649220

3. Chen AM, Grekin RC, Garcia J, Bucci MK, Margolis LW.Radiation therapy for cutaneous squamous cell carcinoma involving the parotid area lymph nodes: dose and volume considerations.Int J Radiat Oncol Biol Phys. 2007 Dec 1;69(5):1377-80.

4. Wallace A, Morris CG, Kirwan J, Amdur RJ, Werning JW, Mendenhall WM. Radiotherapy for squamous cell carcinoma of the nasal vestibule.Am J Clin Oncol. 2007 Dec;30(6):612-6.

5. Moore BA, Weber RS, Prieto V, El-Naggar A, Holsinger FC, Zhou X, Lee JJ, Lippman S, Clayman GL. Lymph node metastases from cutaneous squamous cell carcinoma of the head and neck. Laryngoscope. 2005. Sep;115(9):1561-7.

6. Thomas Habif, ed. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 1996.

7. Rowe DE, Carroll RJ, Day CL: J Am Acad Dermatol 26:976-990, 1992.