Canis ISSN: 2398-2942

Oral squamous cell carcinoma: labial and lingual

Introduction

• Less common than the gingival form; mucosal surface of lip/cheek or tongue.
• Signs: dysphagia, hypersalivation.
• Lip/cheek may respond to wide local surgical resection; lingual more aggressive with very poor prognosis unless early recognition.
• Treatment: for non-operable soft tissue masses, radiotherapy may offer a 50% survival at 1 year.
  The tongue has too narrow a therapeutic index for radiotherapy treatment.
• Prognosis: soft tissue masses: 5-10% regional lymph node metastases; 3-36% distant metastases.
• Lingual: overall metastatic rate of 37.5%.

Pathogenesis

Predisposing factors

• Lingual - some relationship to white-coated animals.

Pathophysiology

• Lingual and lip/cheek - route of spread via local lymph nodes → thoracic metastases.
• Lingual - rostral site has improved prognosis over caudal location, where lymphatic drainage is denser and risk of metastatic spread higher.
• Lingual - typically rapid extension and invasion into the tongue → full thickness involvement.
• Lip/cheek commonly ulcerative rather than proliferative → less prompt to metastasize.

• Primary tumor → local lymph node metastases → distant metastases, usually thoracic.
• Lingual - recent attempt to grade histological features with clinical characteristics:
  • Grade 1 - relatively benign.
  • Grade 2 - aggressive surgery with or without chemotherapy.
  • Grade 3 - poor prognosis.

Timecourse

• Lingual: owner median referral time - 1.5 months (10 cases).

Diagnosis

Treatment

Outcomes