Laryngeal cancer: classification

Modern classification of larynx cancer is based on the location, stage of development and histological structure of the tumor. Of the various forms of cancer of the larynx squamous cell is found in 95%, glandular - in 2%, basal cell - in 2%, other forms - in 1% of cases. The tumor growth form is subdivided into exophytic (into the laryngeal cavity), endophytic (into the laryngeal tissue) and mixed. From a practical point of view, according to the topographical principle, laryngeal cancer can be classified as follows:

1. cancer of the upper larynx (vestibular cancer, cancer supragloticum), localized on the posterior surface of the epiglottis, in the pre-nodular space, in the scaly folds and other areas of the laryngeal threshold;
2. cancer of the middle larynx (cancer gloticum), affecting the vocal folds and the front commissure area;
3. cancer of the lower larynx (cancer subgloticum), covering the tissues of the lining space to the lower edge of the cricoid cartilage.

Vestibular cancer, arising from one side, very quickly embraces the opposite side and sprouts into the pre-northerly space. Cancer, which occurs in the ventricles of the larynx, rapidly prolapses into the laryngeal lumen, causing a violation of voice formation and respiration. Crayfish of the middle larynx are the most frequent and localize at the initial stage exclusively at one voice store - cancer in situ. Vocal disorders caused by this form of cancer contribute to its early diagnosis, hence, the prognosis under this form is the most favorable. This is facilitated by the fact that the cancer of the vocal fold long remains monolateral and very late passes to other areas of the larynx. Cancer of the lining space usually refers to tumors of infiltrative growth and very quickly spreads to the opposite side, hitting the front commissure and both vocal cords.

The lower limit of cancer of the lining space is most often limited by the lower edge of the thyroid cartilage, but in its development this form of cancer can descend to the lower boundary of the cricoid cartilage, and in neglected cases, go to the tracheal rings.

The spread of larynx cancer is hindered by obstructions in the form of ligaments and muscles of the larynx, but lymph vessels contribute to this spread, which, however, also have their own barrier in the form of vocal folds, where they are greatly reduced. Upper suprami lymphatic vessels are associated with anatomical formations of the anterior larynx (epiglottis, cherpalodnagortan folds, ventricles of the larynx). Collecting lymph from these formations, lymphatic vessels, penetrating the lateral part of the lining of the thyroid, flow into the upper jugular lymph nodes, where they enter metastases from the corresponding regions.

The lower lymphatic network provides the collection of lymph from the anatomical formations of the lining space; it forms two ways of outflow: one of them (anterior), penetrating the peristonechitovidnuyu membrane, falls into pre- and peritracheal, as well as the lower jugular lymph nodes; another way (posterior), permeating the perstetracheal membrane, flows into the lymph nodes of the recurrent nerves and hence into the lower jugular nodes.

The medial area of the lymphatic vasculature is represented by a small number of very thin vessels located along the vocal folds and weakly anastomosing with the upper and lower lymphatic vasculature, which explains the rare and later metastasis from this area to the above lymph nodes.

Metastases in distant organs with cancer of the larynx are not so frequent: 4% - in the lungs, 1,2% - in the esophagus, liver, bones; even more rarely - in the stomach, intestines and brain.

In practice, the international classification of laryngeal cancer using the TNM system is widely used (6th edition, 2002)

Primary tumor (T):

• T - primary tumor;
• Tx - insufficient data to estimate the primary tumor;
• T0 primary tumor is not detected;
• Tis preinvasive carcinoma (carcinoma in situ).

Vestibular department:

• T1 - the tumor is limited to one anatomical region of the vestibular part, the mobility of the vocal folds is preserved.
• T2 - a tumor affects the mucosa or several anatomical parts of the vestibular department or one part of the vestibular department and one or more parts of the vocal folds, the mobility of the vocal folds is preserved:
• TK - tumor is limited to the larynx with fixation of the vocal folds and (or) spreading on the posterior celiac or pre-nodular tissues:
• T4a - the tumor extends to the thyroid cartilage and (or) other tissues adjacent to the larynx: trachea, thyroid, esophagus, soft tissues of the neck, including deep muscles (chin, tongue, tongue and tongue), sublanguage muscles;
• T4b - the tumor extends to the prevertebral space, the mediastinal structures or embraces the carotid artery.

Vocal fold region:

• T1 - tumor is limited to vocal folds without disturbance of mobility (anterior or posterior commissures may be involved);
  • T1a - the tumor is confined to one fold;
  • T1b - the tumor captures both ligaments;
• T2 - the tumor extends to the vestibular and (or) podogolosovoy department, and (or) the mobility of the vocal folds is impaired:
• T3 - the tumor is limited to the larynx with fixation of the vocal folds and (or) damage to the near-lining space and (or) damage to the thyroid cartilage (inner plate);
• T4a - the tumor extends to the thyroid cartilage and (or) adjacent to the larynx tissue: trachea, thyroid, esophagus, soft tissues of the neck, muscles of the tongue, pharynx.
• T4b - the tumor extends to the prevertebral space, the mediastinal structures or embraces the carotid artery.

Under the voice area:

• T1 - tumor is limited to the podogolosovym department;
• T2 - the tumor extends to one or both vocal cords with free or limited mobility;
• T3 - tumor is limited to the larynx with fixation of the vocal fold;
• Т4а - the tumor extends to cricoid or thyroid cartilage and (or) on adjacent to the larynx tissue: trachea, thyroid, esophagus, soft tissue of the neck;
• T4b - the tumor extends to the prevertebral space, the mediastinal structures or embraces the carotid artery.

Regional lymph node involvement (N):

• Nx - insufficient data for assessment of lesions of regional lymph nodes;
• N0 - there are no signs of regional lymph node involvement:
• N1 - metastases in one lymph node on the side of the lesion up to 3 cm in the largest dimension;
• N2 - metastases in one or more lymph nodes on the side of the lesion up to 6 cm in the largest measurement or metastases and lymph nodes of the neck on either side or on the opposite side up to 6 cm in the largest dimension;
  • N2a - metastases in one lymph node on the affected side to 6 cm in the largest dimension;
  • N2b - metastases in several lymph nodes on the affected side up to 6 cm in the largest dimension;
• N2c - metastases in several nodes of the neck from both at times or on the opposite side up to 6 cm in the largest measurement;
• N3 - metastases in the lymph nodes more than 6 cm in the largest dimension.

Remote metastases (M):

• Mx - insufficient data to determine distant metastases;
• M0 - no signs of distant metastases;
• M1 - there are distant metastases.

Histopathological differentiation (G):

• GX - the degree of differentiation can not be established;
• G1 - high degree of differentiation;
• G2 - the average degree of differentiation;
• G3 - low degree of differentiation;
• G4 - undifferentiated tumors.

Pathological classification (pTNM). The categories pT, pN, pM correspond to categories T, N and M of the international classification. In the material obtained with partial cervical lymph node dissection, there must be at least 6 lymph nodes. In the material obtained with radical lymphadenectomy, no less than 10 lymph nodes for morphological investigation.

[1], [2], [3], [4], [5], [6], [7], [8], [9],