Published on October 31, 2018
1. ANATOMY AND HISTOLOGY OFTHE HEAD & NECK Dr.Sameera Rashid ResidentAnatomical pathology
2. Why so important? ■ Communication with surgeons, radiologists ■ Aiding the diagnosis ■ Staging ■ Therapy depends on localization and extension of disease.
3. ■ Suprahyoid neck: – Nasopharynx – Oral cavity – Oropharynx ■ Infrahyoid neck – Larynx – hypopharynx
4. The Division?? ■ Two embryological separate parts of the larynx ■ The supraglottis has buccopharyngeal origin: rich lymphatic pathways LN metastases are more frequent ■ The glottis and the subglottis are derived from the tracheobronchial buds: fewer lymphatic pathways, Rare LN metastasis
5. Nasopharynx ■ Anterior: Nasal cavity ■ Post: spine ■ Contains opening of the eustachian tube, adenoids ■ Rich capillary lymphatic plexus—Retropharyngeal LN
6. Oropharynx ■ Anterior: Oral cavity ■ Post:Vertebral column ■ Contents:The tonsils ■ Oral cavity: stratified squamous with parakeratosis.
7. The oral cavity is separated from the oropharynx by ■ the anterior tonsillar pillars ■ the circumvallate papillae, ■ Junction of soft and hard palate
8. Palatine tonsils
9. Retromolar Gingiva (Retromolar Trigone). ■ This is the attached mucosa overlying the ascending ramus of the mandible from the level of the posterior surface of the last molar tooth and the apex superiorly, adjacent to the tuberosity of the maxilla.
10. Lymph nodes ■ Level I: submental, submandibular ■ Level II: upper jugular ■ Level III: mid jugular ■ Level IV: lower jugular ■ LevelV: posterior triangle ■ LevelVI: pre-laryngeal, pre/paratracheal ■ LevelVII: upper mediastinal
11. Epiglottis: stratified squamous epithelium similar to oral cavity, with modified salivary glands that secrete thick mucous; False vocal cords and other supraglottic larynx: ciliated, columnar epithelium,with submucosal modified salivary gland epithelium Glottis: space between two vocal cords Hypopharynx: covered by non-keratinizing stratified squamous epithelium; contains mucosal glands, scattered lymphoid aggregates and rich lymphatic plexus True vocal cords: stratified squamous epithelium with no / rare submucosal glands Subglottic larynx: epithelium resembles trachea / major bronchi - ciliated columnar epithelium with submucosal glands
12. ■ The epiglottic epithelium is stratified and squamous.The epithelium in the false cords is ciliated columnar, whereas the epithelium in the true cords is stratified squamous.
13. In case of tumor invasion of the anterior commissure, all neighboring structures are at risk for neoplastic all neighboring structures are at risk for neoplastic destruction