Epithelial Malignancies

Oral Cancer Subsites: Oral Cavity

Includes ANTERIOR 2/3 OF TONGUE, floor of mouth, buccal/labial mucosa, HARD PALATE, and gingiva.

Oral Cancer Subsites: Oropharynx

Includes SOFT PALATE, POSTERIOR 1/3 (base) OF TONGUE, palatine tonsils, and posterior pharyngeal wall.

Most common extrinsic factors in OSCC etiology

tobacco

EtOH

sunlight (lip vermilion)

oncogenic viruses - HPV 16

Instrinic factors in OSCC etiology

nutritional deficiencies (Fe, vitamin A)

immunosuppression

genetic mutations (TP53, RB1, CDKN2A, RAS, MYC, EGFR, PIK3CA)

Clinical morphology of Oral SCC

Exophytic

Endophytic

Leukoplakic

Erythroplakic or erythroleukoplakic

+/- pain, induration, destruction of underlying bone, paresthesia

Oral SCC High-Risk Sites

Posterior lateral and ventral tongue, and the floor of the mouth.

Primary Oncogenic Virus in Oropharyngeal SCC

Human Papillomavirus type 16 (HPV 16).

Clinical Morphology of Oral SCC

Can present as exophytic, endophytic, leukoplakic, or erythroplakic lesions.

Lip Vermilion SCC Etiology & Location

Most commonly affects the lower lip due to chronic ultraviolet (UV) light exposure.

Lip Vermilion SCC

~90% lower lip

chronic UV light exposure

light-skinned

relatively slow growing

mets late (

Oropharyngeal SCC

Esp. tonsillar region

Close association with HPV 16

Sore throat, dysphagia, odynophagia, painless neck mass

Metastasis often present at diagnosis

HPV-Positive Oropharyngeal SCC Clinical Features

Occurs mainly in tonsils/base of tongue, presents with early lymph node metastasis, but carries a favorable prognosis.

SCC: Microscopic Features

Field Cancerization

Diffuse mucosal changes increased by carcinogens leading to multiple primary synchronous or metachronous tumors.

TNM Staging: 'T' Definition

Refers to the size and depth of invasion (extent) of the primary tumor.

TNM Staging: 'N' Definition

Refers to the spread to regional lymph nodes

TNM Staging: 'M' Definition

Distant metastasis

Basic Treatment Options for Oral SCC

Surgery (conventional resection, transoral robotic surgery for OPSCC)

Radiation (IMRT, de-escalation for HPV-positive OPSCC)

Chemotherapy (cisplatin, carboplatin, 5-FU, deintensification for HPV-positive OPSCC)

Biologics (cetuximab, immune checkpoint inhibitors)

Oral SCC: Importance of Follow-up / FIELD CHARACTERIZATION

~3-7% of head and neck cancer SCC patients per year develop an additional primary malignancy, with 20-year cumulative risk of 36%

SCC Variants: Verrucous Carcinoma Characteristics

A low-grade SCC variant linked to chronic tobacco use with rare metastasis.

SCC Variant: Basaloid Squamous Cell Carcinoma

cells with dark nuclei/little cytoplasm; often oropharynx/HPV positive

CARCINOMA OF THE MAXILLARY SINUS

Uncommon

Mainly older adults

Carcinoma of the Maxillary Sinus: Etiology

Etiology largely unknown

not related sinusitis or nasal polyps

only weak assoc. w/tobacco

wood/leather dust (intestinal-type variant only

recent evidence of increasing HPV-positive subset

Maxillary Sinus Carcinoma Presentation

Chronic unilateral nasal stuffiness and facial pain/paresthesia often mimicking a toothache.

Nasopharyngeal Carcinoma Primary Etiologic Factors

Epstein-Barr virus (EBV) infection, genetic susceptibility, and dietary nitrosamines (salted fish), tobacco (weak association)

Nasopharyngeal Carcinoma

Unilateral otitis media, hearing loss, epistaxis, nasal obstruction, pain

50-60% pts: 1st sign enlarged cervical lymph node

Treatment: radiation +/- systemic therapy

Prognosis: Overall 5-yr survival ~61%

BASAL CELL CARCINOMA

Most common skin cancer

Most common of all cancers

Arises from the basal cell layer of epidermis

Basal Cell Carcinoma (BCC) Origin & Common Site

Arises from epidermal basal cells; 80% occur in head and neck skin from sun exposure.

Basal Cell Carcinoma: Features

locally invasive, slowly spreading malignancy

etiology: chronic sun exposure

esp. fair complexioned adults

~80% cases occur in skin of head and neck

Basal Cell Carcioma: Types

>20 clinicopathologic types

more common types:

noduloulcerative

pigmented

morpheaform (sclerosing)

superficial

Basal Cell Carcinoma: Treatment

Excision, electrodessication, curettage

If high risk for recurrence: Mohs surgery

Basal Cell Carcinoma: Prognosis

Recurrence uncommon

Metastasis very rare

Need periodic follow-up (~44% develop 2nd lesion within 3 years)

MELANOMA

Malignancy of melanocytes

3rd most common skin cancer (after BCC and SCC)

Accounts for most skin cancer deaths

Melanoma: Risk Factors

light complexion/hair/eyes

history of severe sunburns in childhood

tendency to sunburn or freckle easily

family or personal history of melanoma

Melanoma: Sites

Skin > mucosa

Oral mucosal melanoma is very rare

Melanoma Clinical Diagnostic Criteria (ABCDE)

Asymmetry, Border irregularity, Color variation, Diameter >6 mm, and Evolution/Elevation.

Oral Mucosal Melanoma Predilection & Prognosis

Most common on the hard palate/maxillary mucosa; carries an extremely poor prognosis (5-yr survival 10-25%).

Melanoma: Treatment & Prognosis

guided by TNM staging

oral melanoma: extremely poor prognosis (5-yr survival ~10% to 25%)