Oral cavity
Squamous cell carcinoma
Lip

Author: Anshu Jain, M.D. (see Authors page)

Revised: 25 April 2018, last major update February 2014

Copyright: (c) 2004-2018, PathologyOutlines.com, Inc.

PubMed Search: Squamous cell carcinoma[TI] lip[TI] full text[sb]

Cite this page: Jain, A. Squamous cell carcinoma - lip. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/oralcavityscclip.html. Accessed October 17th, 2018.
Definition / general
  • Malignant epithelial neoplasm exhibiting squamous differentiation characterized by the formation of keratin or the presence of intercellular bridges
  • Categorized with squamous cell carcinoma of oral cavity
  • ~0.6% of all cancers in U.S.
  • Lip is somewhat common but often overlooked site of nonmelanoma skin cancer (NMSC), including the two most common types - basal and squamous cell carcinoma (BCC and SCC)
  • Up to 95% of NMSCs on lower lip are squamous cell carcinoma
  • Usually occurs in fair skinned males age 50+
Epidemiology
  • Age: fourth - sixth decade
  • Gender: male:female = 3:1; males are 3 - 13 times more likely to develop lip cancers, likely due to occupation related sun exposure combined with greater tobacco and alcohol use
  • Geographic location: U.S. incidence: 1.8 / 100,000 population; Australia: 13.5 / 100,000 population; parts of Asia: virtually nonexistent
Sites
  • 90% occur on lower lip, usually along vermillion border
  • Lower lip is ~12 times more likely to be affected, due to its greater exposure to sunlight
Pathophysiology
Etiology
  • Risk factors: chronic sunlight, pipe smoking, cigarette smoking, poor oral hygiene, fair complexion and organ transplant recipients
Clinical features
  • Persistent nonhealing ulcer / blister
  • Lump or thickening on the lips
  • More advanced lesions: large bleeding masses / disfigurement
  • Low risk of metastatic extranodal spread; early to adjacent skin, orbicular muscle; late to buccal mucosa, mandible and mental nerve
  • Lower lip: metastases initially to ipsilateral submental and submandibular nodes, then jugular lymph nodes
  • Upper lip: metastases to preauricular and infraparotid lymph nodes
  • Midline lesions may metastasize to contralateral lymph nodes
Grading
  • Grade 1: Well differentiated
  • Grade 2: Moderately differentiated
  • Grade 3: Poorly differentiated
  • Grade X: Cannot be assessed
Staging / staging classifications
TNM staging:
  • See staging topic
  • Superior mediastinal lymph nodes are considered regional lymph nodes (level VII)
Radiology description
  • Ancillary imaging studies (Panorex, CT scan, MRI) indicated when tumor is attached to mandible, for metastatic neck disease or perineural invasion
Radiology images

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Irregular lobulated contour

Prognostic factors
  • Given their highly visible location, the majority of lip cancers are easily detectable and treatable at an early stage
  • Poor prognostic factors:
    • Large size (metastatic rate: > 4 cm - 73%, 2 - 4 cm - 50%, < 2 cm - 5%), nodal metastases
    • Features in deep tumor: high tumor grade, tumor thickness > 6 mm, aggressive invasion pattern, perineural invasion
  • Relapse rate: 5 - 35%
  • Mortality rate for large / recurrent SCC: as high as 15%
  • 5 year survival after lymph node spread: ~50%
Case reports
  • Neonatal squamous cell carcinoma of the lip (J Clin Oncol 2011;29:e549)
  • 55 year old man with misdiagnosis of lip squamous cell carcinoma (RSBO 2012;9:114)
  • 73 year old woman with advanced squamous cell carcinoma involving both upper and lower lips and oral commissure with simultaneous reconstruction by local flap (J Med Case Rep 2012;6:23)
Treatment
  • Surgery, radiation and cryotherapy (freezing with liquid nitrogen), with almost 100% cure rates for early lesions
  • MOHS surgery is reserved for early stage lesions that are thin (less than 2.5 mm depth) without lip muscle involvement
Clinical images

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Preoperative view

Immediate postoperative

Two weeks postoperative

5 months postoperative with tumor recurrence

Advanced carcinoma of the lower lip

Relapsing carcinoma

Gross description
  • May be exophytic (verrucous or papillary), endophytic, ulcerated
Microscopic (histologic) description
  • Usually well differentiated, often invades bone
  • Metastases to submandibular lymph nodes, often less well differentiated
Microscopic (histologic) images

Images hosted on other servers:

H&E

Squamous cell carcinoma

Positive stains
Negative stains
Differential diagnosis