Tumours of the Hypopharynx
The hypopharynx, a crucial part of the pharynx, is located behind and partially on the sides of the larynx. It extends from the level of the hyoid bone superiorly (C3) to the lower border of the cricoid cartilage (C6), where it becomes continuous with the oesophagus. Hypopharynx is divided into three areas: (i) the pyriform sinus, (ii) the post-cricoid region, and (iii) the posterior pharyngeal wall.
Endoscopic view of Hypopharynx
Incidence and Demographics:
Hypopharyngeal cancers are relatively rare, representing less than 0.5% of all cancers and 3-5% of head and neck cancers. These malignancies are most commonly diagnosed in individuals over 50, with a peak incidence in the sixth and seventh decades of life. The pyriform sinus is the most frequent site of origin, followed by the posterior pharyngeal wall and post-cricoid area. Gender differences are notable, with pyriform and posterior pharyngeal wall lesions being more prevalent in males, while postcricoid cancers are more common in females. A key characteristic of hypopharyngeal tumours is their tendency for early lymph node metastasis, particularly to levels II and III. This propensity for occult nodal metastases complicates investigating, staging, and treating these cancers. Metastases to paratracheal, and paraesophageal (level VI) are more common in lesions involving post-cricoid or pyriform sinus apex while retropharyngeal nodes can be involved in posterior pharyngeal wall cancers.
Endoscopic view of Carcinoma Hypopharynx
Risk Factors:
Several factors contribute to the development of hypopharyngeal cancers, including:
- Tobacco use
- Alcohol consumption
- Human papillomavirus (HPV) infection
- Hypochromic microcytic anaemia (Plummer-Vinson syndrome)
- Lower body mass index (BMI)
- Occupational exposure to formalin fumes, coal dust, steel dust, and iron compounds
Symptoms:
Hypopharyngeal tumours are often detected in advanced stages due to the nonspecific nature of early symptoms. Patients may experience:
- Mild throat discomfort or a Globus sensation
- A neck lump, particularly at levels II and III, is often the first clinical sign
- Odynophagia (painful swallowing)
- Dysphagia to solid foods, especially in post-cricoid cancers
- Hoarseness, indicative of late-stage disease or laryngeal involvement
- Unilateral referred otalgia (ear pain)
- Significant weight loss, particularly in post-cricoid or oesophageal tumours
Clinical Examination and Signs:
A thorough clinical examination should include:
- A detailed history of tobacco and alcohol use
- Evaluation for halitosis
- Palpation of neck nodes
- Observation for widening of the thyroid cartilage
- Assessment of laryngeal crepitus (Trotter’s sign), especially in post-cricoid cancers
- Observation for pooling of saliva, especially in pyriform sinus cancers
Investigations:
Diagnostic approaches for hypopharyngeal tumours include:
- Barium Esophagogram: Useful for screening and determining the lower extent of post-cricoid cancers.
- Flexible Transnasal Esophagoscopy: Maps the lesion and assesses proximity to the cricopharynx and esophagus.
- Direct Laryngoscopy: Essential for biopsy and assessing the extent of the lesion under general anaesthesia.
- Fine-Needle Aspiration Cytology (FNAC): Confirms neck node involvement, avoiding the need for open biopsy.
- Contrast-Enhanced CT (CECT): Preferred for defining tumour size and its relationship to deep structures; MRI is used for complex cases.
- Chest X-ray or CT: Screens for distant metastasis, particularly in advanced tumours.
- FDG PET/CT: Valuable for assessing recurrent disease post-radiation therapy.
Staging of Hypopharynx cancer
Types of Hypopharyngeal Tumors:
- Benign Tumors: Rare, including papilloma, adenoma, lipoma, fibroma, and leiomyoma. Typically present as smooth, well-defined, and sometimes pedunculated mobile masses.
- Malignant Tumors: Squamous Cell Carcinoma: The most common type in the hypopharynx, especially in India. Non-squamous malignancies, originating from minor salivary glands or mesenchymal tissues, are rare.
A. Carcinoma of the Pyriform Sinus
Incidence: Most common, accounting for 60% of hypopharyngeal cancers, predominantly in males over 40.
Spread: The tumour can spread locally to nearby structures such as the vallecula, base of the tongue, post-cricoid region, aryepiglottic folds, and ventricles, potentially infiltrating the thyroid cartilage or gland. Early lymphatic spread often involves the upper and middle jugular nodes, with 75% of patients presenting with cervical nodal metastases, half of whom have bilateral involvement. Distant metastases typically affect the lungs, liver, and bones at a later stage.
Symptoms: Early symptoms include mild throat discomfort and a pricking sensation on swallowing. As the disease progresses, dysphagia, referred otalgia, hoarseness, and laryngeal obstruction may occur, often signifying laryngeal oedema or disease spread to the larynx.
Diagnosis: Evaluation includes mirror examination, barium swallow, and CT scan to assess tumour extent and lymph node involvement. Endoscopic examination is necessary for biopsy and accurate assessment of the growth, as well as to identify any synchronous primary tumours.
Treatment: Early-stage tumours without nodal involvement can be effectively treated with radiotherapy, preserving laryngeal function. If the tumour is confined to the pyriform fossa and has not extended to the postcricoid region, total laryngectomy and partial pharyngectomy may be performed, often combined with elective or prophylactic neck dissection. Advanced cases involving the postcricoid region may require total laryngectomy and pharyngectomy with reconstruction using myocutaneous flaps or stomach pull-up, followed by postoperative radiotherapy.
B. Carcinoma of the Post-Cricoid Region
Incidence: Accounts for 30% of hypopharyngeal malignancies, with a strong association with Plummer-Vinson syndrome.
Spread: Tumors often invade the cervical esophagus, arytenoids, or recurrent laryngeal nerve, leading to airway obstruction and aspiration. Submucosal spread to the cervical esophagus is common, with lateral spread potentially involving the carotid sheath. Lymphatic spread often affects paratracheal lymph nodes, with bilateral involvement due to the midline location of these lesions.
Symptoms: Typically affects females, sometimes as early as their twenties and thirties. Progressive dysphagia is the primary symptom, leading to malnutrition and significant weight loss. Voice changes or aphonia may occur due to recurrent laryngeal nerve involvement or posterior cricoarytenoid muscle infiltration.
Diagnosis: Post-cricoid growths may not be visible on indirect laryngoscopy. Suggestive signs include oedema and erythema of the post-cricoid region and pooling of secretions in the hypopharynx. Loss of laryngeal crepitus and increased prevertebral shadow on lateral neck radiographs may also be noted. Barium swallow and endoscopy are essential for diagnosis and assessment.
Treatment: The prognosis is generally poor, regardless of treatment modality. Initial radiotherapy is preferred for preserving laryngeal function, while advanced cases may require laryngopharyngoesophagectomy with stomach pull-up or colon transposition for reconstruction.
C. Carcinoma of the Posterior Pharyngeal Wall
Incidence: The least common, accounting for 10% of hypopharyngeal malignancies, predominantly affecting males over 50.
Spread: Tumors tend to spread exophytically to adjacent areas such as the base of the tonsil, oropharyngeal wall, and cervical oesophagus, with a lymphatic spread often being bilateral.
Symptoms: Common symptoms include dysphagia, spitting of blood, and neck masses.
Diagnosis: Indirect mirror examination and lateral soft tissue radiography are useful for assessing the tumour’s vertical extent and thickness, as well as any involvement of the cervical vertebrae. Endoscopy is essential for biopsy and detailed evaluation.
Treatment: Early exophytic lesions can be treated with radiotherapy, preserving laryngeal function. Small lesions may also be surgically excised via lateral pharyngotomy, with comparable outcomes. Advanced lesions may require laryngopharyngectomy with neck dissection and food channel repair. The overall 5-year cure rate is approximately 19%.
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Reference Textbooks.
- Scott-Brown, Textbook of Otorhinolaryngology-Head and Neck Surgery.
- Cummings, Otolaryngology-Head and Neck Surgery.
- Stell and Maran’s, Textbook of Head and Neck Surgery and Oncology.
- Ballenger’s, Otorhinolaryngology Head And Neck Surgery
- Susan Standring, Gray’s Anatomy.
- Frank H. Netter, Atlas of Human Anatomy.
- B.D. Chaurasiya, Human Anatomy.
- P L Dhingra, Textbook of Diseases of Ear, Nose and Throat.
- Hazarika P, Textbook of Ear Nose Throat And Head Neck Surgery Clinical Practical.
- Mohan Bansal, Textbook of Diseases of Ear, Nose and Throat Head and Neck Surgery.
- Hans Behrbohm, Textbook of Ear, Nose, and Throat Diseases With Head and Neck Surgery.
- Logan Turner, Textbook of Diseases of The Nose, Throat and Ear Head And Neck Surgery.
- Arnold, U. Ganzer, Textbook of Otorhinolaryngology, Head and Neck Surgery.
- Ganong’s Review of Medical Physiology.
Author:
Dr. Rahul Bagla
MBBS (MAMC, Delhi) MS ENT (UCMS, Delhi)
Fellow Rhinoplasty & Facial Plastic Surgery.
Renowned Teaching Faculty
Mail: msrahulbagla@gmail.com
India
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