Squamous cell carcinoma of the head and neck

Squamous cell carcinoma of the head and neck
Diagnosis in short
Squamous cell carcinoma of the head and neck (larynx). H&E stain.
Synonyms	squamous cell carcinoma of the head and neck not otherwise specified
Subtypes	keratinizing type, undifferentiated type, nonkeratinizing type
LM DDx	squamous dysplasia of the head and neck, HPV-associated head and neck squamous cell carcinoma, nasopharyngeal carcinoma, malignant melanoma, metastatic squamous cell carcinoma, NUT carcinoma
IHC	p63 +ve, CK5/6, p16 -ve, EBER -ve
Site	head and neck - tongue (dealt with separately)
Clinical history	smoking, excessive drinking
Prevalence	common
Prognosis	moderate-to-poor
Treatment	surgery, radiation

Squamous cell carcinoma of the head and neck, abbreviated head and neck SCC, is a common malignant epithelium neoplasm of the head and neck.

This is an overview article that deals only with the usual squamous cell carcinoma of the head and neck, or squamous cell carcinoma of the head and neck not otherwise specified (abbreviated SCC of the H&N NOS).

Tongue squamous cell carcinoma is dealt with in separate article.

The human papilloma virus-associated SCC is dealt with in HPV-associated head and neck squamous cell carcinoma. Nasopharyngeal carcinoma is also dealt with separately.

General

• Most common malignant tumour of the head & neck.
• Most common spindle cell tumour of the head & neck.

Classification

SCC is subdivided by the WHO into:

• Keratinizing type (KT).
  • Worst prognosis.
• Undifferentiated type (UT).
  • Intermediate prognosis.
  • EBV association.
• Nonkeratinizing type (NT).
  • Good prognosis.
  • EBV association.

Microscopic

Features based on classification:

• Keratinizing type (KT) subtype:
  • Keratinization & intercellular bridges through-out most of the malignant lesion.
• Undifferentiated type (UT):
  • Non-distinct borders/syncytial pattern.
  • Nucleoli.
• Nonkeratinizing (NT):
  • Well-defined cell borders.

DDx:

• SMARCB1-deficient sinonasal carcinoma.
• Sinonasal undifferentiated carcinoma.
• Human papillomavirus-related multiphenotypic sinonasal carcinoma - previously known as HPV-related carcinoma with adenoid cystic-like features.
• NUT carcinoma - has well-differentiated squamous "islands" that are sharply demarcated from poorly differentiated surrounding tumour.
• Neuroendocrine tumour.
• Metastatic squamous cell carcinoma of skin - esp. parotid lesions; history of skin SCC (esp. lateral aspect of head).

Invasion

Features:

• Eosinophilia.
• Extra large nuclei/bizarre nuclei.
• Inflammation (lymphocytes, plasma cells).
• Long rete ridges.
• Numerous beeds/blobs of epithelial cells that seem unlikely to be rete ridges.

Pitfalls:

• Tangential cuts.
  • If you can trace the squamous cells from a gland to the surface it is less likely to be invasive cancer.

Notes on invasion:

• Reviewed by Wenig.
• See SCC of the cervix versus CIN III.

Images

• 

  Invasive oral SCC. (WC)

• 

  Laryngeal SCC - intermed. mag.

• 

  Laryngeal SCC - high mag.

• 

  Laryngeal SCC - very high mag.

Overview of subtypes

There are several subtypes:

• Basaloid - poor prognosis, usu. diagnosed by recognition of typical SCC.
• Warty (Condylomatous).
• Verrucous - good prognosis, rare.
• Papillary.
• Lymphoepithelial, rare.
• Spindle cell, a common spindle cell lesion of the H&N.

Verrucous squamous cell carcinoma

Features:

• Exophytic growth.
• Well-differentiated.
• "Glassy" appearance.
• Pushing border.

DDx: papilloma.

Spindle cell squamous carcinoma

• Key to diagnosis is finding a component of conventional squamous cell carcinoma.

IHC:

• Typically keratin -ve.
• p63 +ve.

DDx:

• Spindle cell melanoma.
• Mesenchymal neoplasm.

Basaloid squamous cell carcinoma

• May mimic adenoid cystic carcinoma.
• Classically base of tongue.
• Typically poor prognosis.

Features:

• Need keratinization. (???)

Lymphoepithelial (squamous cell) carcinoma

See nasopharyngeal carcinoma.

IHC

• p63 +ve.
• p16 -ve.
  • Positive suggests HPV-associated head and neck squamous cell carcinoma.
• Bcl2 +ve/-ve.
  • Positive = poor prognosis.

Molecular

• EBER -ve.
  • Positive suggests nasopharyngeal carcinoma.

Sign out

LESION, TONGUE/FLOOR OF MOUTH BORDER, BIOPSY:
- INVASIVE KERATINIZING SQUAMOUS CELL CARCINOMA, MODERATELY DIFFERENTIATED.

LEFT NECK (LONG SUTURE LEVEL IA AND SHORT SUTURE LEVEL IIB), LEVEL
   I-IV, DISSECTION:
- LEVEL IA:
-- ONE LYMPH NODE WITH SQUAMOUS CELL CARCINOMA, AND FOUR LYMPH NODES
   NEGATIVE FOR MALIGNANCY (1 POSITIVE/5).
-- BENIGN SALIVARY GLAND.
-- SEE COMMENT.
- LEVEL IIA:
-- FIVE LYMPH NODES NEGATIVE FOR MALIGNANCY (0 POSITIVE/5).
- LEVEL III:
-- FIVE LYMPH NODES NEGATIVE FOR MALIGNANCY (0 POSITIVE/5).
- LEVEL IV:
-- TEN LYMPH NODES NEGATIVE FOR MALIGNANCY (0 POSITIVE/10).

COMMENT:
The squamous cell carcinoma is moderately differentiated and shows rare 
keratinization. The tumour lies adjacent to benign (submandibular) salivary 
gland which it does not involve.

Micro

Biopsy

The section shows atypical (squamous) cells with moderate grey cytoplasm, central nuclei with small nucleoli, infiltrating between fibrous tissue. Abundant keratin pearls are present. The nuclei are predominantly pale staining and focally have irregular nuclear membranes and irregular chromatin. Mitotic activity is not readily apparent. Necrosis is present focally.

See also

• Head and neck pathology.
• Squamous cell carcinoma.