Lateral tongue tumors frequently metastasizing directly to level II nodes
Involvement of level V nodes:
In the absence of positive nodes in levels I to IV is rare:
However it is not unusual for nodes in level IV to be involved:
Hence even in elective neck dissections levels I to IV should be dissected
Like floor of mouth tumors:
The presence of lingual lymph nodes should be considered and either an in-continuity resection with the neck specimen or clearance of tissue above the mylohyoid conducted
Bilateral neck dissections:
Should be considered in tumours that extend to or beyond the midline.
The management of the neck in larger primary tumors:
Is usually straightforward since the neck is accessed for microvascular or pedicled flap reconstruction of the primary site
Management difficulties arise with smaller tumors amenable to peroral resection and local closure
It has been proposed that the increased incidence of nodal metastasis associated with tongue carcinoma:
May be due to contraction of tongue muscles promoting entry of cancer cells into the lymphatics
It is thought that mechanism by which tumor thickness is related to cervical metastasis:
Is that thicker tumors have access to wider lymphatics:
In which tumor emboli can form more readily
Although tumors arising on the lateral aspect of the tongue tend to be thicker than those of the ventral aspect of the tongue:
This may not manifest as a greater risk of cervical metastasis, since the ‘critical thickness’ for tumors of the floor of mouth is less than other oral sites
Elective neck dissection or elective neck radiotherapy:
Should be considered for tumors thicker than 3 mm to 4 mm:
T2 or greater in dimension and T1 tumors that demonstrate poor histological features:
Poor differentiation
Double DNA aneuploidy
Degree of differentiation at the advancing front
Elective neck dissection:
Significantly improves loco-regional control:
It has been demonstrated that conducting an END reduces regional recurrence from 47% in ‘watch and wait’ patients to 9% if END is conducted
END has been shown by some to improve five-year survival:
The five-year survival of patients undergoing therapeutic neck dissection following a ‘watch and wait’ policy being 35% as opposed to 69% when an elective neck dissection is conducted
Others, however, have not demonstrated a survival advantage
Should be conducted if surgery is the treatment of choice
The use of ultrasonography :
To aid in assessment of surgical clearance had been advocated by some:
Particularly for the deep margin
Frozen section:
Can be used (its my practice) but some centers do not routinely used it:
Even with apparently adequate margins during surgery:
10% of resections may demonstrate histologically positive margins
The aim of reconstruction of the oral tongue following resection:
Is to ensure maximum function of the residual tongue tissue:
Since the complex function of the tongue cannot be replicated with current reconstructive techniques
Preservation of the tip of the tongue:
While maintaining oncologically sound resection margins:
Helps maximize postoperative function
The use of monopolar electrocautery:
Cutting through mucosa changing to coagulation when in muscle, or the harmonic scalpel:
Helps reduce bleeding during the resection:
However this is at the cost of lack of feel afforded by the use of scalpel or scissors
If both lingual vessels are resected:
Then the viability of the tip of tongue remnant should be carefully assessed:
Sacrifice of both hypoglossal nerves results in a nonfunctioning tongue tip
Small lesions may be removed with a laser and allowed to heal by secondary intention
T1 and small T2 primary tumors:
May be excised with a vertical wedge and the defect closed primarily:
If the defect does not extend to significantly to include the floor of mouth
Many larger lesions benefit from free flap reconstruction of the defect:
Usually with a radial free forearm flap:
Although the anterolateral thigh free flap is being used more frequently
The skin paddle of the chosen free flap:
Should be fashioned so as not to restrict residual tongue function and should hopefully augment swallowing
Typically, the reconstruction should be of the same size, or slightly smaller than the defect created by the resection
Care should be taken in the design of the flap:
When the defect extends to include adjacent sites:
Such as the soft palate or floor of mouth
The mobile tongue and floor of mouth:
Should be ‘separated’ in the reconstruction:
To minimize restriction of movement of the residual tongue
Thin radial free flaps may have their bulk increased by extending fascial flaps beyond the skin island:
The fascial flaps then being folded and buried underneath the epithelial reconstruction
Reconstruction of large resections:
May be accompanied by measures aimed to improve postoperative function:
Such as static laryngeal suspension to the mandible and cricopharyngeal myotomy
Once the specimen is removed, it is examined for clearance and orientated for the pathologist:
A digital photograph being useful
Radiotherapy as the primary treatment modality can be used in certain situations:
Has been advocated since it conserves tongue volume and morphology:
Brachytherapy being considered preferable to external beam radiotherapy:
Osteoradionecrosis of the mandible is a recognized complication of brachytherapy of the tongue:
Up to 9% developing some form of osseous complication
The use of brachytherapy to the primary site:
Requires either surgery or external beam radiotherapy to the neck in an elective or therapeutic manner:
When surgery is not conducted as the primary treatment:
Valuable prognostic information is lost:
Since the primary tumor is not examined histologically:
This makes the decision as to whether to conduct an END more difficult
It has been suggested that surgery is superior to brachytherapy in the management of stage I / II tongue cancer:
By conducting surgery as the primary treatment modality, radiotherapy is kept in reserve for either poor prognostic indicators of the resected specimen, for management of recurrence or management of second primaries which commonly occur at a later date
The need for aggressive treatment of floor of mouth carcinomas:
Is well recognized
Surgical resection with a 1 cm margin should be achieved:
If surgery is the preferred treatment modality
Even in the best surgeon’s hands:
Positive or close margins may be seen in up to 47% of resections:
Despite the use of intra-operative frozen section:
Many floor of mouth tumors are infiltrative with indistinct edges:
Possibly explaining the high incidence of positive margins
Further resection is advocated if margins are positive
Although 1 cm margins are considered by most surgeons to be adequate:
Extended 2 cm margins have been advocated by some
The early extension of floor of mouth tumors into the tongue or mandible:
Is demonstrated by the fact that many patients require marginal (rim) or segmental resection of the mandible
Surgical resection of the floor of mouth in the majority of circumstances:
Will involve resection of part of the submandibular ducts:
Typically, the ducts will be resected at the resection margin, well away from their orifice:
However in smaller resections at least 3 mm length of duct proximal to the orifice:
Should be taken to ensure surgical clearance of carcinoma or dysplasia that may extend along the duct
Management of the submandibular ducts is of great importance if a neck dissection is not being conducted with consequent removal of the submandibular gland:
Stricture of the duct in the presence of a functioning gland:
May give rise to obstructive symptoms of the gland and difficulty in differentiating the potential submandibular gland swelling from cervical disease
The ducts should be transected obliquely to minimize stricture formation and repositioned at the margin of resection, ideally being stented
Alternatively, the ducts may be found proximal to the resection margin:
A longitudinal incision made and the duct ‘marsupialized’ to the floor of mouth mucosa:
Uninvolved branches of the lingual nerve should be identified and preserved
Small resections:
May be left to heal by secondary intention or a split thickness skin graft applied
A more substantial reconstruction may be achieved using local nasolabial or facial artery musculomucosal flaps:
However an edentulous segment is required when using both of these flaps to accommodate their pedicle
If a neck dissection is required and surgical facilities allow;
Microvascular reconstruction provides a far more flexible reconstructive option, without necessarily prolonging operative time if a two team approach is adopted
Reconstruction with split skin graft
The radial free forearm flap is an ideal reconstructive option for floor of mouth defects:
Easily being converted to a composite flap if segmental resection of an edentulous mandible is required
Prefabricated fasciomucosal free flaps have been described in oral reconstruction:
However their role in oncological reconstruction is questioned
The fibula osteocutaneous flap provides superior reconstruction if a segmental resection is anticipated in a dentate patient:
Although like the composite radial free flap:
Flexibility of the skin paddle is limited
The scapula osteocutaneous flap:
With two skin paddles, or one skin paddle and muscle left to mucosalize:
Provides an excellent reconstruction of large defects involving mucosa, bone and external skin
Radiotherapy techniques (brachytherapy or external beam):
For T1 / T2 primaries have been shown to provide results similar to surgery
The proximity of the floor of the mouth to the mandible:
Is of concern when using brachytherapy:
Since up to 8.5% of patients treated with this modality require segmental resection of the mandible:
Due to osteoradionecrosis within 10 years
Several units have described a change in practice from brachytherapy to surgery:
As the primary treatment modality due to the risk of complications
T3 / T4 lesions:
Are best treated with surgery and postoperative radiotherapy
Management of the Neck in Floor of the Mouth SCC:
Regional spread of disease in floor of mouth carcinomas is usually to the ipsilateral level I to III lymph nodes:
Involvement of multiple levels not being unusual
Lesions towards the midline:
May spread to both sides of the neck:
Hence bilateral neck dissections should be considered
The presence of lingual lymph nodes:
Has raised the concept of in-continuity neck dissection in an attempt to reduce local recurrence and improve survival:
Resection of the tumor accompanied with the complete clearance of the floor of the mouth, preserving mylohyoid, hyoglossus and genioglossus if possible, so clearing the lingual lymph nodes would seem an acceptable method of managing lingual lymph nodes
The decision to conduct an elective neck dissection has been related to tumor size or depth of invasion:
Lesions that are T2 or greater:
Should have an elective I to III / IV selective neck dissection:
Although elective neck dissections have been advocated for T1 lesions
Tumor thickness of 4 mm is often used as a ‘generic’ critical thickness, greater than which an elective neck dissection is indicated:
Since the risk of occult metastasis is greater than 20%:
It has been demonstrated that the risk of cervical metastasis of floor of mouth tumors exceeds 20% in tumors as thin as 1.5 mm to 2 mm:
Using a thickness of 1.5 mm may result in up to 32% of patients requiring END based on thickness criteria
The indications for postoperative radiotherapy to the loco-regional area are similar to other sites:
Notably two or more involved nodes in the neck
Extracapsular spread
Positive margins
Stage III / IV disease
Postoperative radiation therapy (PORT):
The beneficial role of PORT in selected patients with floor of mouth carcinoma has been demonstrated
Recurrence:
Recurrence rates for floor of mouth carcinoma are 26% to 55%:
Usually within the first two years
Factors that influence recurrence include:
Tumor size
Margin status
Tumor thickness
Advanced nodal disease
Prognosis
Overall five-year survival for floor of mouth carcinoma:
Is 52% to 76%
Factors that potentially influence survival include:
It is thought that the high incidence of cancer at this site may be due to pooling of saliva with dissolved carcinogens or lack of keratinized epithelium
Within the anatomical site:
Tumors are more likely to occur anteriorly
Floor of mouth carcinoma:
Occurs more frequently in men:
The age at diagnosis usually being in the sixth to seventh decade
Floor of mouth cancer, as does oral cancer at all sites:
Has a strong association with smoking and the consumption of alcohol
Increased local recurrence and decreased long-term prognosis
Indications for postoperative radiotherapy (PORT) include:
Positive or close margins:
However despite PORT:
Local recurrence rates do not approach those in which adequate clearance is achieved at the primary operation
Increasing resection margins in the region of the head and neck:
Potentially results in increased functional and cosmetic deficit
Resection margins of up to 2 cm have been advocated:
However such margins result in significant functional deficit following the resection of even the smallest of tumors
Three-dimensional, 1 cm resection margins:
Have been demonstrated as acceptable when dealing with oral and oropharyngeal tumor:
Adopting 1 cm surgical margins:
Account is taken of the shrinkage that occurs post-resection:
So ensuring greater than 5 mm pathological margins
It should be remembered that the use of 5 mm as a cut-off point for ‘clear’ margins is arbitrary and purely represents a margin that is considered acceptable
It is vitally important to continually reassess margins visually and by palpation during tumor resection
If approaching the resection of a tumor with curative intent:
Then reconstructive considerations should not influence the tumor resection
Comparison of published data regarding the incidence of positive margins and their influence on survival or local recurrence is complicated by the variable definition of a positive margin:
The definition of a positive margin ranges from:
Invasive tumor at the margin, tumor within 1 mm and tumor within 5 mm
The UK Royal College of Pathologists have issued guidelines:
Suggesting clear margins if the histological clearance is 45 mm
Close margins if 1 mm to 5 mm
Positive margins if less than 1mm
The incidence of positive margins for tumors of the oral cavity:
Has been demonstrated as being higher than other head and neck sites:
Potentially due to its complex anatomy and three-dimensional shape
Large tumors, perineural spread, vascular permeation, a noncohesive invasive front or cervical metastasis:
Are all associated with a greater risk of failing to achieve clear margins:
These features suggest that close or involved margins:
Potentially reflect a more aggressive tumor
The incidence of close or involved margins following tumor resection may be greater than 60% depending on tumor site and size:
Invariably, it is the deep margin that is close or positive:
However close deep margins do not necessarily require adjunctive treatment:
The use of ultrasonography to aid in determining deep margin resection has been described
Frozen sections are not routinely used by many surgeons:
Reasons cited being potential cost
Inability to reliably prevent positive final margins
Poor relocation of biopsy site should the result be positive
Ninety-nine percent of American head and neck surgeons:
Routinely use frozen section intraoperatively:
However overreliance on frozen section may result in undertreatment of tumors
When conducting a bony resection:
A 1 cm margin should be achieved:
It has been demonstrated that it is unusual for extension of tumor in bone to exceed the overlying soft tissue extension
Is the mucosal lining of the inner surface of the cheek
The area extends from:
The oral commisure anteriorly to the retromolar trigone posteriorly:
The junction between the buccal mucosa and retromolar trigone:
Is an arbitrary line drawn from the maxillary tuberosity to the distobuccal aspect of the mandibular third molar (or its anticipated position if not present)
The inferior and superior boundaries of the area are delineated by:
The mandibular and maxillary gingivobuccal sulci, respectively
The buccal mucosa is not exposed to masticatory loads:
So is covered by a lining mucosa with nonkeratinizing stratified squamous epithelium:
The mucosa is firmly attached to the underlying buccinator muscle
Minor salivary glands are located within the cheek (submucosa)
The parotid duct:
Pierces the buccinator muscle to enter the oral cavity adjacent to the second maxillary molar tooth
Sensory innervation to the area:
Is via the buccal branch of the mandibular division of the trigeminal nerve
Lymphatic drainage of the site:
Is via the ipsilateral facial and submandibular nodes:
To the deep cervical chain
The thickness of the cheek, from mucosal lining to external skin:
Is 1 cm to 3 cm
Epidemiology
The buccal mucosa is the most common site for oral cancer:
In South East Asia:
Up to 40% of oral cancers arising at this site
This contrasts with North America and Western Europe:
Where buccal carcinoma only accounts for 2% to 10% of oral carcinomas
The consumption of betel quid:
Is socially and culturally embedded in the countries of South East Asia:
It is responsible for the difference in site predilection
The ingredients of betel quid (paan / paan masala) varies throughout South East Asia:
The main ingredients include:
The piper betel leaf
Slaked lime
Spices
Tobacco
Areca nut
For many years, the tobacco content alone was credited as being the carcinogenic agent in betel quid:
However it is now recognized that the areca nut is also carcinogenic:
As well as being the main etiological agent in:
Oral submucous fibrosis
Individuals who consume betel quid frequently have a preference regarding which side they chew betel:
This corresponding to the side of tumor development
There is a strong association with smoking and alcohol consumption:
In populations where betel chewing is not prevalent
The male-to-female ratio:
In Western countries approximates 1:1:
However in South East Asia the ratio reflects the consumption of betel quid
In India, the male-to-female ratio is approximately 4:1
In the Taiwanese population, where betel quid use occurs primarily in the male population:
The ratio may be as high as 27:1
Buccal carcinoma typically occurs over the age of 40 years:
Although it may occur in younger patients:
Particularly when associated with the habit of betel chewing
Presentation:
Buccal carcinoma may be described as:
Verrucous, exophytic or ulceroinfiltrative in character
Squamous cell carcinoma buccal mucosa of verrucous appearanceSquamous cell carcinoma buccal mucosa of ulceroinfiltrative appearance
Presentation of buccal carcinoma of the oral cavity:
Patients may present with:
Pain
An intraoral mass
Ulceration
Trismus
Patients who chew betel often have areas of:
Erythroleukoplakia of the buccal mucosa or submucous fibrosis and consequent trismus:
Making the detection of invasive squamous cell carcinoma difficult
Advanced buccal carcinomas may extend into adjacent sites to include:
External skin, mandible or maxilla
It is not unusual for patients to present with advanced disease:
40% or more presenting with stage III / IV disease
Palpable lymphadenopathy on presentation:
May be as high as 57% for T3 / T4 lesions
Occult nodal metastasis:
May be present in 26% of those who are clinically N0 at presentation:
Tumors greater than T2, are poorly differentiated, have a poor lymphocytic response or are thicker than 5 mm:
Are more likely to demonstrate cervical metastasis
Tumors are usually well differentiated
Work up:
Biopsies of buccal carcinomas should be of sufficient depth to help the pathologist give an indication of depth of invasion:
Since this will help decide on management of the neck
Buccal carcinoma may rapidly extend to adjacent sites:
Thus accurate imaging is required:
Most patients will require MRI / CT imaging:
Augmented with ultrasound scan if necessary to help in the assessment of depth of primary and cervical lymphadenopathy
Treatment
Primary site:
Traditional treatment of buccal carcinoma is:
Surgery with postoperative radiation therapy (PORT) for selected patients
T1 / T2 disease:
Can typically be resected perorally
T3 / T4 disease:
May require facial access incisions and bony resection of the maxilla and / or mandible
The primary tumor should be resected with:
A 1 cm margin and up to 2 cm if skin is involved
The buccinator muscle:
Should be included as the deep margin at the very least
The parotid duct:
May need to be repositioned or ligated
External skin should be taken with the specimen:
If there is any evidence clinically or on imaging that it is involved
Partial maxillectomy or mandibular resection (rim (marginal) or segmental) may be required.
Small T1 tumors:
May be resected and reconstructed by primary closure
Healing by secondary intention may be considered:
However postoperative trismus may be anticipated:
Unless vigorous mouth opening exercises are conducted
Split thickness skin grafts may be used:
The use of silicone sheets to stabilize the graft being useful
The use of a skin graft to reconstruct deeper resections:
May leave a very thin cheek with potentially poor aesthetics
Local flaps such as:
The buccal fat pad or temporoparietal fascial flap:
May be used for reconstruction if tumor extension does not compromise their use
Microvascular free flap reconstruction with a radial free forearm flap or anterolateral thigh flap:
Restores the thickness of the cheek and if external skin is involved:
The flaps can be bipaddled to provide reconstruction of mucosal and skin surfaces
T4 tumors requiring segmental resection of the mandible:
May require composite free flap reconstruction
Reconstruction with a radial free forearm flap:
Has been shown to give better postoperative mouth opening than reconstruction with a split skin graft or buccal fat pad
As a single treatment modality for T1 / T2 tumors has been advocated:
However, a change of practice from radiotherapy to surgery at Memorial Sloan Kettering Cancer Center was associated with improved prognosis
Brachytherapy or external beam irradiation may be considered
Management of the Neck:
Regional spread of disease in buccal carcinoma is usually to:
The ipsilateral level I and II lymph nodes
Patients with palpable lymphadenopathy or pathological nodes on imaging:
Should have a comprehensive neck dissection:
Although if pathological nodes are only located in level I, a level I to III selective neck dissection (SND) may be considered
Nodes in the region of the facial artery as it crosses the mandible:
Should be removed with the neck dissection specimen
Patients with a cN0 neck:
With a T2 or greater primary tumors or tumors with a thickness greater than 5 mm:
Should have an elective neck dissection:
Some institutions will conduct an elective neck dissection (END) if the tumor is 3 to 4 mm thick or if histological examination of the tumor demonstrates lymphatic infiltration
PORT:
The indications for postoperative radiotherapy to the loco-regional area are similar to other sites:
Notably two or more nodes in the neck, extracapsular spread (ECS), positive margins or stage III / IV disease
The beneficial role of PORT in selected patients with buccal carcinoma has been demonstrated by several authors:
Some authors suggest that PORT should be considered even in stage I and II disease, or tumors greater than 10 mm thick
Recurrence:
Recurrence rates for buccal carcinoma are 26% to 80%:
Usually occurring within two years
Involvement of the parotid duct and buccinator:
Have not been found to be significant indicators of recurrence
Rodrigo Arrangoiz MS, MD, FACS, FSSO 