Читать книгу Hypopharyngeal Cancer - Группа авторов - Страница 34

Specific sub-sites within the hypopharynx [12, 13] have been described by the code number of the International Classification of Diseases for Oncology (ICD 0–3; C 12 [code for tumours located in the piriform sinus with a single code C 12.9], C 13 [code for tumours located in the other sites of the hypopharynx of which there are five sub-sites (C 13.0, 13.1, 13.2, 13.8 and 13.9)]); the postcricoid area, the piriform sinus, and the posterior pharyngeal wall (Fig. 1).

Table 2. Sub-site distribution by continents

The pharyngo-oesophageal junction (C 13.0; postcricoid area) extends from the level of the arytenoid cartilages and connecting folds to the inferior border of the cricoid cartilage, thus forming the anterior wall of the hypopharynx.

The piriform sinus (C 12.9) is a bilateral area, which extends from the pharyngo-epiglottic fold of the upper end of the oesophagus. It is bound laterally by the thyroid cartilage and medially by the hypopharyngeal surface of the aryepiglottic fold (C 13.1) and the arytenoid and cricoid cartilages.

The posterior pharyngeal wall (C 13.2) extends from the superior level of the hyoid bone (or floor of the valeculla) to the level of the inferior border of the cricoid cartilage and from the apex of one piriform sinus to the other.

In the majority of large patient series, piriform sinus cancer is diagnosed most frequently in 65–70% of patients, with posterior pharyngeal wall making 15–20% and postcricoid area 10–15%. However, in large tumours, it may be difficult to be accurate specifying with sub-site the tumour started, and clinicians have used the prime symptom reported by the patient to aid with classification. Geographic variations of sub-sites are reported in differing continents (Table 2).