Oral cavity
Squamous cell carcinoma
Palate

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

Revised: 25 April 2018, last major update April 2014

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

PubMed Search: Squamous cell carcinoma[TI] palate[TI]

Cite this page: Jain, A. Squamous cell carcinoma - palate. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/oralcavitysccpalate.html. Accessed August 17th, 2018.
Definition / general
  • ~2% of all head & neck mucosal malignancies / 5 - 6% of intraoral squamous cell carcinoma
  • Most common malignancy of palate (50% of hard palate, 80% of soft palate cancers)
Anatomy
  • Divided into hard palate (part of oral cavity) and soft palate (part of oropharynx)
Epidemiology
  • Age: older (> 50 years)
  • Gender: male > female
Pathophysiology and sites of involvement
  • Usually soft palate
  • 70% of hard palate SCCs extend beyond the hard palate, 30% show cervical nodal involvement at presentation (especially submandibular, upper deep jugular, retropharyngeal nodes)
  • 50% of soft palate SCCs extend beyond soft palate, 20 - 30% show cervical nodal involvement at presentation, 25% have synchronous or metachronous lesions in upper aerodigestive tract, lung or esophagus
Etiology
  • Known etiological association with tobacco and alcohol consumption: soft palate SCC
  • Association with reverse smoking (smoking a cigarette or cigar from the lit end): hard palate SCC
  • Other less convincing factors: ill fitting dentures, poor oral hygiene, mechanical irritation, mouthwash
Clinical features
  • Ulcer, pain, mass, bleeding, foul odor, ill fitting dentures, loose teeth
  • Changes in speech, difficulty swallowing, unable to open the jaw (trismus), lump in neck
  • Tumor extension beyond hard palate is associated with velopharyngeal insufficiency and hypernasal speech, palatal hypesthesia, absent corneal reflex, dental numbness, middle ear effusion
Grading
  • Grade 1: Well differentiated
  • Grade 2: Moderately differentiated
  • Grade 3: Poorly differentiated
  • Grade X: Cannot be assessed
Staging / staging classifications
TNM staging:
  • Staging for cancer of the oropharynx and oral cavity, adapted from the 2002 American Joint Committee on Cancer, is as follows:
    • Staging of primary tumor (T)
      • TX: Primary tumor not assessable
      • T0: No evidence of primary tumor (Tis: carcinoma in situ)
      • T1: Tumor 2 cm or smaller in greatest dimension
      • T2: Tumor larger than 2 cm but not larger than 4 cm in greatest dimension
      • T3: Tumor larger than 4 cm in greatest dimension
      • T4: Tumor invades adjacent structures (e.g. through cortical bone, soft tissues of neck, deep [extrinsic] muscle of tongue)
    • Staging of regional lymph nodes (N)
      • NX: Regional lymph nodes not assessable
      • N0: No regional lymph node metastasis
      • N1: Metastasis in a single ipsilateral lymph node, 3 cm or smaller in greatest dimension
      • N2: Metastasis in a single ipsilateral lymph node, larger than 3 cm but not larger than 6 cm in greatest dimension; in multiple ipsilateral lymph nodes, none larger than 6 cm in greatest dimension; or in bilateral or contralateral lymph nodes, none larger than 6 cm in greatest dimension
      • N2a: Metastasis in a single ipsilateral lymph node larger than 3 cm but not larger than 6 cm in greatest dimension
      • N2b: Metastasis in multiple ipsilateral lymph nodes, none larger than 6 cm in greatest dimension
      • N2c: Metastasis in bilateral or contralateral lymph nodes, none larger than 6 cm in greatest dimension
      • N3: Metastasis in a lymph node larger than 6 cm in greatest dimension
    • Staging of distant metastasis (M)
      • MX: Presence of distant metastasis cannot be assessed
      • M0: No distant metastasis
      • M1: Distant metastasis
Radiology description
  • CT and MRI are modalities of choice
  • CT scan: to assess bony invasion (coronal plain), extension into nasal fossa, maxillary sinus and skull base
  • MRI scan: to assess perineural extension along the foramina, dural invasion in case of intracranial invasion and to differentiate between inflammatory disease vs. neoplasm in cases of advanced tumor with paranasal sinus invasion
  • Orthopantomography (Panorex): a panoramic Xray of the upper and lower jaw, shows a view from ear to ear and helps determine if a tumor has grown into the jaw bone
  • Chest Xray: to detect lung metastasis
Prognostic factors
  • Advanced N stage: worse prognosis
  • Size
  • Location
  • Tumor thickness: excellent predictor of nodal metastasis especially in soft palate SCC
Case reports
Treatment
  • Varies by location (hard palate / soft palate), stage
  • Hard palate:
    • T1, T2 SCC: surgery ± radiotherapy
    • T3, T4 SCC: surgery + radiotherapy
    • N0: elective neck dissection vs. observation (controversial)
    • N1: neck dissection ± postoperative radiotherapy
    • N2: neck dissection + postoperative radiotherapy
  • Soft palate:
    • All T, N0, N1: radiotherapy (because of difficulties in adequate reconstruction after surgery)
    • ≥ N2: neck dissection + postoperative radiotherapy
Clinical images

Images hosted on other servers:

Erosive lesion

SCC of hard palate

Gross description
  • Exophytic / proliferative is most common; also ulcerated / infiltrative
Microscopic (histologic) description
  • Hard palate SCC: usually well differentiated
  • Soft palate SCC: usually moderate to poorly differentiated
Microscopic (histologic) images

Images hosted on other servers:

Invasion of lamina propria mucosa

With marked inflammation

MIB1

Positive stains
Negative stains
Differential diagnosis