oropharyngeal tumorsslideshare

Oropharyngeal Tumors

Balasubramanian Thiagarajan

drtbalu's otolaryngology online

Introduction

• Oropharynx is at the crossroads between respiratory and digestive tracts

• Malignant lesions in this area alters swallowing, speech and breathing

• Treatment plans should focus on anticipated functional outcome in addition to disease clearance

• Neoplasm of oropharynx are uncommon. Majority of tumors encountered in this area are malignant in nature


Anatomy

• Extent:

Superior – Hard Palate

Inferior – Hyoid bone

• For purposes of tumour classification:

Anterior wall

Posterior wall

Lateral wall

Roof


Anterior wall of oropharynx

• Tongue base posterior to circumvallate papillae

• Presence of lymphoid aggregates (Nodular appearance)

• Lymphatics from tongue base course downwards towards the hyoid bone

• At the level of hyoid bone lymphatics pierce pharyngeal wall to drain into upper deep cervical level II nodes

• Midline tumors exhibit bilateral nodal involvement due to cross over lymphatic drainage patterns


Lateral wall of oropharynx

Tonsils

Tonsillar fossa

Tonsillar pillars

Lateral pharyngeal wall

Lateral to lateral pharyngeal wall lies the para pharyngeal space

Lymphatics from upper lateral wall drain into retropharyngeal nodes


Posterior pharyngeal wall

• Extends from the level of hard palate/Passavant’s ridge superiorly to the level of hyoid bone inferiorly

• Mucosa is smooth with occasional lymphoid tissue

• First echelon node is retropharyngeal node, then later into level II and level III nodes


Roof of oropharynx

• Formed by curved arch of the inferior surface of the soft palate and uvula in midline

• Tumors of this area drain into upper JD and retropharyngeal nodes


Nerve supply of oropharynx

Sensory supply – Glossopharyngeal nerve

Motor supply – Vagus

Base of tongue – Hypoglossal nerve (motor)

Soft palate – Motor and sensory by Trigeminal nerve

Vagus / glossopharyngeal nerves – auricular and tympanic branches causes referred otalgia in these patients


Blood supply / Lymphatic drainage

• Branches of external carotid artery

• Lymphatic drainage to levels II and III neck nodes

• Central structures – tongue base, soft palate and posterior pharyngeal wall have bilateral neck node drainage

• Tonsillar region drain into retropharyngeal nodes


Pharyngeal spaces associated with oropharynx

• Two pharyngeal spaces are associated with oropharynx

• Retropharyngeal space & parapharyngeal spaces


Facial spaces around oropharynx (contd)

Retropharyngeal space

Lies between buccopharyngeal fascia of pharynx and the alar layer of prevertebral fascia. Extends from skull base to the superior mediastinum. Communicates with parapharyngeal space laterally.

Parapharyngeal space

Extends from skull base to the hyoid bone. This space is divided into prestyloid and post styloid compartments.

Prestyloid compartment contains fat and deep lobe of parotid gland and a small branch of trigeminal nerve to tensor veli palatini muscle.

Post styloid compartment contains carotid artery, jugular vein, cranial nerves 9th to 12th sympathetic chain and lymph nodes.

Benign tumors

• Common in oral cavity than oropharynx

• Benign tumors include Papilloma, adenoma, fibroma, hemangioma, leiomyoma, schwannoma, neurofibroma, lingual thyroid.



Benign tumors

Clinical presentation

• Rarely produce symptoms

• Symptoms vague and non specific causing delay in diagnosis

• Usually present very late

• Ear pain

• FB sensation in throat

• Impaired tongue movements and speech due to tongue muscle infiltration

• Fetor / foul breath

• Neck lump


Difference between benign and malignant tumors


Malignant tumors

• Sq cell carcinoma

• Lymphoepithelioma

• Lymphoma

• Salivary gland tumors

• Metastatic tumors


Squamous cell carcinoma

• Commonest

• Tonsils and faucial pillars – 45%

• Soft palate – 15%

• Posterior tongue – 40%

• Posterior pharyngeal wall – 5%


Sq cell carcinoma

Tonsil Posterior tongue

Soft palate Posterior pharyngeal wall

Etiology of sq cell carcinoma

• Smoking

• Alcohol consumption

• Dietary deficiencies vitamin A

• Chronic irritants

• Papilloma virus

• HIV


Lymphoepithelioma

• Variant of sq cell carcinoma

• Undifferentiated carcinoma

• Common in tonsil and base of tongue

• Associated with nodal metastasis

• Behaviour is similar to NPC


Lymphoma

• Non Hodgkin’s common

• Tonsil / base of tongue

• Commonly High grade B cell type

• Common in Men

• Not associated with fetor


Salivary gland tumors

• Arise from minor salivary glands of soft palate

• Adenocarcinoma / adenocystic carcinoma


TNM classification

• T0 – No evidence of primary tumor

• Tis – Carcinoma in situ

• T1 – Tumor 2 cm or less in greatest dimension

• T2 – Tumor more than 2 cm but not more than 4 cm in greatest dimension

• T3 – tumor more than 4 cm in greatest dimension

• T4a – Tumor invades larynx, deep/extrinsic muscle of tongue, medial pterygoid, hard palate or mandible

• T4b – Tumor invades lateral pterygoid, pterygoid plates, lateral nasopharynx, skull base, carotids


Nodal status

• Nx – regional nodes cannot be assessed

• N0 – No regional node metastasis

• N1UL – Metastasis in a single ipsilateral node 3 cm or less in greatest dimension

• N2UL – Metastasis of single ipsilateral node more than 3 cms but not more than 6 cms in greatest dimension. If multiple none of the nodes should be more than 6 cms

• N2a – Metastasis of single ipsilateral node more than 3 cms but less than 6 cms

• N2b – Multiple ipsilateral nodes none more than 6 cms

• N2c – Metastasis in bilateral / contralateral nodes none more than 6 cms

• N3UL – Metastasis in a node more than 6 cms


Histological classification

• Gx – Grade cannot be assessed

• G1 – Well differentiated

• G2 – Moderately differentiated

• G3 – Poorly differentiated


UICC / AJCC Staging


N0 N1 N2 N3

I

II

III

IV

T1

T2

T3

T4

Evaluation

• Symptoms vague

• Present at advanced stage (stage III / IV)

• Complete examination of upper aerodigestive tract

• Tongue lesions should be palpated

• Examination under GA is preferred if trismus is present

• Lymphomas / adenocarcinoma present as smooth non ulcerative lesions

• Examination of neck nodes

• CT / MRI imaging


Biopsy

• All patients with oropharyngeal tumor should be examined under GA

• If smooth swelling is seen in tonsil – tonsillectomy is preferred

• Tru-cut needle biopsy of posterior third of tongue should be performed under GA

• Possibility of debulking the tumor should be explored


Factors affecting choice of treatment

Tumor factors:

Small accessible tumors – excision

Advanced tongue base tumors – Total glossectomy with total laryngectomy to prevent aspiration. Irradiation is of use in these patients.

Margins of oropharyngeal tumors are not discrete, hence wider resection is preferred.

Exophytic tumors fare well with radiotherapy.

Deep ulcerative tumors are better managed by surgical excision followed by RT


Patient factors affecting treatment modality

• Comorbid conditions

• Patient’s preference

• Presence of advanced dental disease may delay irradiation


Radiotherapy

• Bilateral radiation fields are used to treat whole oropharynx including prophylactic nodal irradiation. Small tonsillar tumors are an exception.

• Concomitant Chemotherapy has improved survival rates

• T1 and T2 tumors respond better to irradiation

• Patients who smoke during irradiation have lower response rates

• Total dose as well as overall treatment duration is important for favourable treatment outcome


Surgery

• Transoral approach

• Transoral/transcervical combined approach

• Transpharyngeal approach

• Transmandibular approach


Transoral approach


Transoral / Transcervical combined approach

• Useful for tongue base lesions

• Tongue and floor of mouth are released, in order to pull these structures below the mandible into the neck

• Mandible split can be resorted to. This helps in improving access.

• Lingual arteries and hypoglossal nerves are at risk during this procedure


Trans pharyngeal approaches

Suprahyoid pharyngotomy – used for small tumors of the tongue base and pharyngeal wall. Entrance into pharynx is usually through the vallecula. This approach allows for preservation of lingual arteries and hypoglossal nerves. Extension of pharyngotomy incision laterally and inferiorly along thyroid ala allows for wider exposure. Superior margins of large tumors cannot be visualized completely. Major advantage of this approach is better functional and cosmetic result.

Lateral pharyngotomy – useful for small tumors of tongue base, tonsil and lateral pharyngeal wall. Pharynx is entered posterior to thyroid ala on the diseased side. Hypoglossal and superior laryngeal nerves should be guarded. After entering the pharynx, larynx is retracted to opposite side before commencement of surgery.


Transmandibular approach

• Includes mandibulotomy and mandibulectomy

• Mandibular split is used if patient has full complement of teeth

• Mandibulotomy should be avoided if periosteum of mandible is involved by the tumor

• Mandibulotomy is made anterior to mental foramen through a tooth socket


Neck management

• Should be considered in all cases of sq cell carcinoma

• Surgery / irradiation can be used

• No neck – Levels I, IIa, IIb, III and upper Va should be performed

• N+ neck – modified / radical neck dissection


Irradiation

• External beam irradiation is preferred

• Stages II / III lesions irradiation followed by neck dissection provides better survival rates.

• Stages III / IV lesions – surgical resection followed by irradiation


RADPLAT

• Targeted chemo radiation protocol

• Cisplatin is infused directly into tumor bed

• Targeted dose of cisplatin is nearly 5 times than that of systemic administration

• Complete regression of tumor occurs in primary site nearly 80% of the time

• Radiotherapy follows chemo

• Very useful in managing advanced oropharyngeal malignancies


oropharyngeal tumorsslideshare

Health & Medicine

upper lateral wall

level of hyoid bone

skull base

tongue base course

hyoid boneat

upper deep cervical

upper jd

prestyloid compartment