Squamous cell carcinoma

  • Most common cancer of the mouth 
  • This is where the cancer starts in squamous cells, the thin flat cells lining the mouth. Cancer may then spread into deeper tissues as they continue to grow.
  • Over 90% of malignant neoplasms of the mouth are squamous cell carcinoma arising form mucosal epithelium, most of the remainder are adenocarcinomas of minor salivary glands
  • Squamous cell carcinoma normally develops in areas of leukoplakia  

Oral cancer
Via @all_things_oral_medicine

Risk factors

  • Smoking 
  • Smokeless tobacco e.g. chewing tobacco products  
  • Excessive consumption of alcohol 
  • Family history 
  • Excessive sun exposure 
  • Human papillomavirus (HPV) 

Warning signs

  • Sudden onset hearing loss
  • Change in voice
  • Difficulty/pain on swallowing
  • Limited mouth opening
  • Altered taste sensation
  • Unexplained weight loss
  • Night sweats
  • Lethargy

Classification

The classification of cancer is staged via the TNM sytsem. It breaks down the classification into 3 categories:

  • T – describes the size/extent of the primary tumour
    • T0 – no sign of primary tumour
    • Tis – carcinoma in situ
    • T1 – less than/equal to 20mm
    • T2 – 20-40mm
    • T3 – more than 40mm
    • Tumour extends into bone, skin and neck
  • N – describes the degree of spread to regional lymph nodes
    • N0 – so tumour cells in regional lymph nodes
    • N1 – single regional metastasis on the same side (less than/equal to 30mm)
    • N2 – single regional metastasis on the same side (30 – 60mm)
    • N3 – tumour spread to contralateral side and to numerous lymph nodes
  • M – describes the presence of metastasis
    • M0 – no distant metastasis
    • M1 – metastasis to distant organs (beyond regional lymph nodes)

Treatment

  • Surgery:  
    • Excision and primary closure  
    • Excision and reconstruction  
    • Radiotherapy  

Epithelial dysplasia

“Epithelial dysplasia is the earliest form of pre-cancerous lesion recognized in a biopsy.” 

The best predictor of the potential for malignant transformation is the degree of dysplasia seen histologically. 

The term dysplasia is defined as epithelial hyperplasia (increase number of cells) and hyperkeratosis.

Dysplasia is usually graded as mild, moderate and severe as a guide to patient management.  

Mild – dysplasia extending the basal 1/3rd of the epithelium (can be reversible)

Moderate – epithelium dysplasia extending the basal 2/3rd of the epithelium (irreversible) 

Severe – epithelium dysplasia extending from the basal membrane to greater than 2/3rd of the epithelium (irreversible)

Carcinoma in situ is a controversial term sometimes used for the most severe dysplasia where the abnormalities extend throughout the thickness of the epithelium; a state sometimes graphically called ‘top-to-bottom change’ 

If the cells breach the basement membrane and enter the lamina propria (cornea) then it’s classed as carcinoma.

Histological features: 

  • Deep cell keratinization 
  • Excessive mitotic activity    
  • Nuclear hyperchromatism 
  • Loss of cell polarity 
  • Loss of intercellular adherence