Supraglottic Cancer Workup

Updated: Mar 05, 2021
  • Author: Joshua D Hornig, MD, FRCSC; Chief Editor: Arlen D Meyers, MD, MBA  more...
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Workup

Laboratory Studies

No specific laboratory studies are necessary for the workup of patients with supraglottic cancer. However, a number of tests may be indicated to evaluate the general health of these individuals.

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Imaging Studies

 

An accurate assessment of the anatomic extent of the tumor is needed, not only to select treatment modalities but also to compare therapeutic results of different modalities. For example, cancer that extends through a boundary, such as the thyroid cartilage or pyriform apex, demands more aggressive treatment than a lesion without such extension. Clinical examination is notoriously inadequate for mapping tumor extent. Forty percent of diagnoses made based on clinical examination are inaccurate. As a result, radiographic assessment is important in the pretreatment workup of patients with laryngeal cancer.

Imaging studies help to define spread to the preepiglottic space (which characterizes T3 carcinoma) and also help to define thyroid cartilage invasion or extralaryngeal submucosal extension (which characterizes T4 carcinoma).

CT scanning and MRI are useful studies in evaluating the spread of supraglottic lesions (see CT Scan of the Larynx), helping to assess involvement of the base of tongue and spread to regional lymph nodes.

Both the preepiglottic and paraglottic space contain mostly fat; hence, CT scans with contrast or MRI scans, especially T1-weighted images, show tumor infiltration into these areas.

Having been shown superior to clinical examination in demonstrating positive lymph nodes, CT scanning and MRI can help to gauge cartilage invasion and help define metastatic spread to the neck.

MRI and CT scans are useful in measuring lymph node size; both can show areas of central lucency, which is consistent with tumor involvement.

Although MRI is somewhat superior with respect to soft-tissue contrast resolution, CT scanning has a faster imaging time, which can reduce motion artifact.

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Diagnostic Procedures

 

To obtain tissue diagnosis and help assess the extent of the disease, direct laryngoscopy is often performed in the operating room.

Videostroboscopy can be helpful in detecting subtle infiltration of the vocal folds.

Panendoscopy (ie, laryngoscopy, bronchoscopy, esophagoscopy, nasopharyngoscopy) has traditionally been the criterion standard used to diagnose second primary lesions. Panendoscopy is controversial, however. Some argue that bronchoscopy and esophagoscopy have only a slightly increased yield over chest radiography and barium swallow and are thus not worth the risks associated with endoscopy. This controversy notwithstanding, most practitioners would agree that direct laryngoscopy, usually under anesthesia, is essential for staging purposes and in obtaining biopsy samples necessary for tissue diagnosis. In the image below laryngoscopic view of the larynx can be seen.

Laryngoscopic view of the larynx. Note the followi Laryngoscopic view of the larynx. Note the following supraglottic structures: epiglottis, aryepiglottic folds, arytenoids, and false folds.

If intraoperative laryngoscopy and biopsy is not appropriate, ultrasonography-guided fine needle aspiration of endolaryngeal advanced supraglottic carcinomas can be performed in the clinical setting without any preparation. According to Lopchinseky et al, this allows for a rapid diagnosis and does not have the costs, side effects, or risks of a direct laryngoscopy. [10]

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Histologic Findings

The mucosa of the supraglottis is composed of nonkeratinizing, stratified, squamous epithelium. Inferiorly, at the level of the laryngeal aditus, this epithelium changes to ciliated, pseudostratified, columnar epithelium at the false folds and the ventricle.

Squamous cell carcinoma (SCC) is classified as well-differentiated, moderately differentiated, or poorly differentiated. Histological findings include anaplastic-appearing cells below the basement membrane with a variable degree of keratin products and intracellular bridges. Microscopic view of squamous cell carcinoma is seen in the image below.

Histological specimen of squamous cell carcinoma ( Histological specimen of squamous cell carcinoma (SCC).
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Staging

Staging of tumors of the supraglottis follows the 2003 definitions of the tumor, node, metastases (TNM) classification elaborated by the American Joint Committee on Cancer and the International Union Against Cancer.

Supraglottic cancer T staging

Stages are designated as follows:

  • Tis - In situ
  • T1 - Limited to 1 subsite with normal cord mobility
  • T2 - Invades mucosa of more than 1 adjacent subsite of supraglottis or glottis or region outside the supraglottis, without fixation of the larynx
  • T3 - Limited to larynx with vocal cord fixation and/or invades the postcricoid area, pre-epiglottic tissues, paraglottic space, and/or minor thyroid erosion
  • T4a - Invades through the thyroid cartilage and/or invades tissues beyond the larynx
  • T4b - Invades prevertebral space, encases carotid artery, or invades mediastinal structures

Node status in supraglottic cancer

Status is designated as follows:

  • N0 - No nodes
  • N1 - Metastasis in a single ipsilateral node that is greater than or equal to 3 cm
  • N2a - Metastasis in a single ipsilateral node more than 3 cm but not more than 3-6 cm in greatest dimension
  • N2b - Metastasis in multiple ipsilateral nodes with none more than 6 cm in greatest dimension
  • N2c - Metastasis in bilateral or contralateral nodes, none more than 6 cm in largest dimension
  • N3 - Metastasis in a lymph node that is larger than 6 cm in greatest dimension

Table. Staging of Supraglottic Cancer (Open Table in a new window)

Stage

Tumor Spread

Node Involvement

Distant Metastases

Stage 0

Tis

N0

M0

Stage I

T1

N0

M0

Stage II

T2

N0

M0

Stage III

T3

N0

M0

T1

N1

M0

T2

N1

M0

T3

N1

M0

Stage IVA

T4a

N0

M0

T4a

N1

M0

T1

N2

M0

T2

N2

M0

T3

N2

M0

 

T4a

N2

M0

Stage IVB

T4b

Any N

M0

 

Any T

N3

M0

Stage IVC

Any T

Any N

M1

 

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