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MANAGEMENT OF ANAPLASTIC THYROID CANCER AND LYMPHOMA
Table 84.1 Staging of anaplastic thyroid cancer
Stage IVA T1, T2, T3a N0 M0
Stage IVB T1, T2, T3a N1 M0
Stage IVB T3b, T4a, T4b N0, N1 M0
Stage IVC Any T Any N M1
Anaplastic Thyroid Cancer
Anaplastic thyroid carcinoma (ATC) is rare, accounting for only 2% of all thyroid cancer. It
is more common in females (F:M, 3:2) and occurs in older patients (median age 65). It is at
the extreme end of a continuum of dedierentiation of dierentiated thyroid cancer (DTC).
Unlike DTC and thyroid lymphoma, ATC has one of the poorest prognoses of any cancer,
with a median survival of only 3–5 months.
Patients commonly present with an enlarging neck mass within a background of pre-existing
goitre. Hoarseness, dysphagia, and stridor are other presentations. Local pain is a less common presentation (15% patients). Extrathyroid extension is usual, with local invasion occurring in up to 90% of cases and distant metastases at presentation in 30–50%. Lung metastases
are common (35%). ATC is classied according to TNM staging (see Table 84.1).
Poor prognostic factors are presence of metastasis, male sex, age over 60, and a large primary
tumour size (>5–7 cm).
Radiology for staging should include computed tomography (CT) of the head, neck, chest,
and abdomen. FDG-PET can be performed to assess for distant disease. Ultrasound-guided
ne-needle aspiration (FNA) or core biopsy can give a histological diagnosis. Flexible
nasoendoscopy is essential to assess vocal cord movement, airway patency, and intraluminal
tumour extension. Once a diagnosis is made, a timely multidisciplinary discussion about further management or best supportive care is imperative.
Treatment
Management of anaplastic thyroid cancer is evolving, with new treatments and trials
ongoing.
Surgery for Potentially Resectable Locoregional Disease
Of patients with ATC, 10% have ATC conned to the thyroid at the time of diagnosis. In this
situation, the goal of surgery is gross tumour resection, not debulking. Aggressiveness of
surgery must be balanced with quality of life; given the prognosis, total laryngectomy should
be avoided. Current guidelines recommend total thyroidectomy and neck dissection only
if R0 (microscopically negative resection) or R1 (grossly negative, microscopically positive)
resection is achievable. Pre-operative evaluation is paramount to determine tumour extent
before undertaking surgical resection.
Adjuvant Therapy
A large Surveillance, Epidemiology and End Results (SEER)-based population study demonstrated that multimodality therapy (surgery + radiotherapy) gives a survival advantage in
resectable disease. Several single-inst itut ion studies have also demonstrated the survival benet of multimodality treatment in the form of surgery + radiotherapy/chemoradiotherapy.
Unresectable Locoregional Disease
Patients who present with unresectable disease have a better outcome following high-dose
radiotherapy ± chemotherapy. Hyperfractionated and accelerated radiotherapy regimes,
with two fractions a day, have been used to try to overcome the rapid growth and potential for tumour cell repopulation. Radiosensitisation with chemotherapy may also be used.
Doxorubicin has been used historically, but recent evidence supports the use of more common head and neck agents, such as cisplatin and taxanes.
428 Head and Neck Endocrine Surgery
MANAGEMENT OF ANAPLASTIC THYROID CANCER AND LYMPHOMA
Toxicity from treatment must be taken into consideration when decisions are being made
about management of patients with ATC. A study assessing a hyperfractionated protocol with
a larger fraction size did not demonstrate any survival advantage but did show signicant
toxicity. e use of intensity modulated radiotherapy (IMRT) allows more concave dose distribution with sparing of normal structures. However, hyperfractionated radiotherapy and
chemoradiotherapy can have signicant treatment-related toxicity for the patient. Enteral
feeding and tracheostomy may be required. In patients with a poor performance status, lowdose radiation may be of palliative benet in helping with pain and obstructive symptoms.
Metastatic Disease
Patients who present with metastatic ATC have a very poor life expectancy. e key for these
patients is to ensure that quality of life is optimised for as long as possible. Short courses
of radiotherapy, as mentioned above, may help control local symptoms. Systemic therapy
response rates are usually poor, with the taxanes, doxorubicin, and cisplatin having the best
clinical response. More recently, the multikinase inhibitors (MKIs) have been used.
KEY POINTS
• Anaplastic thyroid cancer is a very rare disease.
• It has a very poor survival (3–5 months).
• Multimodality treatment is required.
• Surgery is for diagnosis, airway management, and resection if R0 or R1 is possible.
• Newer taxanes can stabilise disease.
• Palliative care and quality of life are important considerations.
Lymphoma
Several dierent lymphoma subtypes can present in the thyroid, but thyroid lymphoma is
very rare, occurring in only 1–2% of patients diagnosed with lymphoma. Management is
dictated by the acuteness of presentation, the histology, and the Ann Arbor stage. ere are
two stages; IE, when only the thyroid gland is involved, and IIE, when cervical or superior
mediastinal lymph nodes are involved. e ‘E’ label is an indication that an extranodal site
(in this case, the thyroid) is involved as a primary site. Histological diagnosis is critical and
ideally involves immunophenotypic and special molecular studies. A ne-needle aspirate
may give a suggestion of lymphoma, but ideally a core-needle biopsy or open biopsy is performed. Fresh tissue, rather than xed, is required. Staging investigations should include a
full lymphoma-protocol CT of the neck, chest, abdomen, and pelvis, and FDG-PET. Blood
tests required include a full blood count, liver function tests, urea and creatinine, and lactate
dehydrogenase (LDH). A bone marrow aspirate and biopsy are also part of routine staging.
For stage I and II disease, the treatment is a curative approach with radiotherapy or combined radiotherapy and chemotherapy.
Indolent Lymphoma
Extranodal marginal lymphomas (MALT) are the most common indolent lymphomas of the
thyroid gland, with follicular lymphoma being the second most common. ere is almost
always pre-existing Hashimoto’s thyroiditis. Patients typically present with a nodule within
the gland or diuse enlargement of the gland. Cervical lymphadenopathy occurs in a third
of cases. Females are more commonly aected than males (3:1). Treatment of stage I and II
is with low-dose radiotherapy (24–30 Gy, fractionated over 2–4 weeks), covering the thyroid and draining cervical nodes. Prognosis is excellent, with local control rates greater than
95% and long-term disease-free survival >90%. If lymphoma is conned to the thyroid, then
surgical resection is also a treatment option.
Head and Neck Endocrine Surgery 429
MANAGEMENT OF ANAPLASTIC THYROID CANCER AND LYMPHOMA
Lymphoma with Aggressive Histology
yroid lymphoma with aggressive histology is the most common, accounting for 65–70%
of cases. Patients are more oen female, with the mean age at presentation being 65. Patients
typically present with a rapidly enlarging mass that is oen as much as 10 cm+ when diagnosed. Cervical lymph nodes are frequently involved. Aggressive lymphoma can arise de
novo or in pre-existing Hashimoto’s thyroiditis. Diuse large B-cell lymphoma is the most
frequent histology, for which there is a well-established treatment, combining chemotherapy
and radiotherapy. Systemic treatment is used, given the high rate of occult systemic disease.
Patients will typically receive the CHOP-R regimen (cyclophosphamide, doxorubicin, vincristine, prednisone, and rituximab), with chemotherapy given for 3–6 cycles followed by
radiotherapy (30–40 Gy) 3–6 weeks later. is systemic treatment can achieve cure rates
of 70–85%. Radiotherapy coverage and volume are dependent on the stage at presentation;
stage IE patients can have radiotherapy limited to the primary thyroid disease only, without
cover of the cervical lymph nodes, while stage IIE patients will typically have radiotherapy
coverage of the thyroid primary site and the draining lymph nodes (Levels III–VI). Longterm cure is 75%.
Toxicity of Treatment
Patients treated with the CHOP-R regime have a standard pre-assessment to minimise toxicity of treatment, which would include the use of premedication, echocardiography, and the
use of growth factor support. Toxicities patients must be warned about when undergoing the
regime include nausea and vomiting, alopecia, mucositis, myelosuppression, increased risk
of infection, and neuropathy. Total radiotherapy doses are low for lymphoma (30–40 Gy), so
toxicity is mild. Xerostomia is not encountered because the treatment volume falls below the
salivary glands.
KEY POINTS
• Thyroid lymphoma represents 1–2% of lymphoma patients.
• Surgery is for diagnosis and airway management.
• Indolent lymphomas can be treated with local therapy (radiotherapy or surgery) and
have an excellent prognosis.
• Lymphoma with aggressive histology requires combined chemotherapy and
radiotherapy and has a long-term cure rate of 75%.
Further Reading
Ferrari SM, Elia G, Ragusa F, Rulli I, La Motta C, Paparo SR, Patrizio A, Vita R, Benvenga
S, Materazzi G, Fallahi P, Antonelli A. Novel treatments for anaplastic thyroid carcinoma. Gland Surg 2020; 9(Suppl 1): S28–S42. doi: 10.21037/gs.2019.10.18.
Glaser SM, Mandish SF, Gill BS, Balasubramani GK, Clump DA, Beriwal S. Anaplastic thy-
roid cancer: prognostic factors, patterns of care, and overall survival. Head Neck 2016;
38(Suppl 1): E2083–2090. doi: 10.1002/hed.24384.
Sharma A, Jasim S, Reading CC, Ristow KM, Villasboas Bisneto JC, Habermann TM,
Fatourechi V, Stan M. Clinical presentation and diagnostic challenges of thyroid lymphoma: a cohort study. yroid 2016; 26(8): 1061–1067. doi: 10.1089/thy.2016.0095.
430 Head and Neck Endocrine Surger y
THYROIDECTOMY
85. THYROIDECTOMY
Introduction
yroid surgery is associated with eodore Kocher, the father of modern thyroid surgery,
whose techniques are still largely used today.
Indications for Thyroid Surgery
Up to 30% of thyroid nodules investigated have an indeterminate pre-operative diagnosis.
yroid lobectomy (TL) is recommended for:
Compressive or autonomously functioning solitary nodules
•
Indeterminate uninodular disease
•
Uninodular dierentiated thyroid cancer (DTC) without extrathyroidal extension (ETE)
•
or metastases
Surveillance of the remaining lobe and regular thyroid function tests are required, as up to
33% of patients develop hypothyroidism.
Total thyroidectomy (TT) is recommended for:
Bilateral multinodular goitre (MNG)
•
Multinodular disease or global dysfunction (e.g. Graves’ disease)
•
≥T3 DTC, medullary thyroid carcinoma, poorly dierentiated thyroid cancer, multi-
•
focal cancer, evidence of ETE, or overt nodal metastases
Subtotal thyroidectomy is no longer recommended.
Pre-Operative Considerations
Findings from clinical examination, cytological or histopathological analysis, and
•
adequate imaging should be available.
Laryngeal examination and pre-operative voice assessment with breoptic laryngos-
•
copy should be performed.
Patients should be euthyroid. In thyrotoxic patients, adequate precautions should be
•
taken to reduce the possibility of thyroid storm (a life-threatening condition associated with elevation of heart rate, blood pressure, and body temperature).
Risks
Hypertrophic/keloid scar
•
Infection
•
Haemorrhage
•
Injury to external branch of the superior laryngeal nerve (EBSLN) and/or recurrent
•
laryngeal nerve (RLN)
Hypocalcaemia
•
Hypothyroidism
•
Tracheostomy
•
With intrathoracic goitre requiring sternal split or lateral thoracotomy, risks include
•
injury to pleura, phrenic nerve, or pericardium; pneumothorax; and pneumonia
Sternotomy carries a 25% risk of respiratory complications (2% with cervical approach). Risk
of deep sternal infection is 1–5%, with sternal dehiscence carrying a 50% mortality rate.
Anesthetic Considerations
Massive goitre can cause intubation diculties; intravenous induction or awake bre-
•
optic intubation is eective.
Head and Neck Endocrine Surgery 431
THYROIDECTOMY
Tracheomalacia due to goitre may require prolonged intubation, supporting sutures,
•
tracheal stenting, or tracheostomy.
Sudden, post-induction cardiorespiratory collapse is a risk, necessitating cardio-
•
pulmonary bypass. is risk is greater with posterior mediastinal goitre and with
extremely low tracheal compression.
Key Goitre Considerations
Posterior mediastinal extension and relationship to neighbouring structures.
•
ETE due to malignancy.
•
Most retrosternal goitres are deliverable cervically.
•
Cardiothoracic input is necessary with primary intrathoracic goitre and in malignant
•
disease with ETE into the chest.
Surgical Technique
Under general anaesthesia with a north-facing neuromonitoring endotracheal tube, position the
patient supine, with a so shoulder support and head ring for neck extension. Via a transverse
cervical incision, divide the subcutaneous fat and platysma. Raise subplatysmal aps from the
thyroid cartilage down to the suprasternal notch and protect the anterior jugular veins.
For large goitre, it may be necessary to extend the incision to the membranous insertion
of the sternocleidomastoid muscle (SCM) and raise subplatysmal aps laterally beyond the
SCM. Division of the most inferior tendinous insertions of the SCM and strap muscles may
improve access.
Incise the cervical fascia in the midline from the thyroid cartilage to the suprasternal notch,
to reveal the isthmus. Dissect out the superior pole and lateral aspect of the gland rst,
before dening Joll’s triangle (lateral border—the upper pole of the thyroid gland and its
vessels; superior border— the attachment of the strap muscles and deep investing layer of
fascia; medial—the midline; and the oor—cricothyroid muscle), within which the EBSLN
is located. Ligate and divide the superior pedicle vessels on the gland to minimise damage
risk to the EBSLN.
Dissect o the strap muscles, then ligate and divide the middle thyroid vein. Dissect the
gland’s fascial layer and mobilise the thyroid to visualise the tracheo-oesophageal groove.
With a large goitre, the carotid sheath may lie anterior, posterior, or lateral to the thyroid.
Extending a nger along the goitre into the mediastinum allows extension assessment and
usually delivery from the chest.
Develop a plane to dissect the inferior pole without jeopardizing the RLN. Identify the RLN;
most are single, but 30% branch before entering the larynx.
Lateral approach: In Beahr’s triangle within the tracheo-oesophageal groove, the RLN
•
forms the third side of a triangle made up of the common carotid artery laterally and
the inferior thyroid artery superiorly.
Superior approach: At the cricothyroid junction as the RLN enters the larynx
•
(Figure 85.1).
Inferior approach: For large goitres and revision surgery.
•
In posterior mediastinal goitre, the nerve can lie anterior to the retrosternal portion
(Figure 85.2). erefore, identify the nerve prior to lobe delivery. Early identication of the
vagus nerve through dissection of the carotid sheath is extremely helpful during goitre surgery. is allows reection of the carotid sheath’s contents o the lateral surface of goitres
as well as vagal monitoring. Ongoing passive vagal monitoring and intermittent stimulation
can be used during goitre surgery to test the ipsilateral vagus and RLN and to ensure that the
RLN is intact during manoeuvres on the goitre that risk neural stretch.
e RLN is at greatest risk at Berry’s ligament. Carefully dissect and divide using bipolar
diathermy on the thyroid away from the nerve down to the tracheal perichondrium. A low
432 Head and Neck Endocrine Surgery
THYROIDECTOMY
Figure 85.1 Recurrent laryngeal nerve identied at the cricothyroid joint.
Figure 85.2 Delivery of right posterior mediastinal goitre through a cervical incision. The recur-
rent laryngeal nerve lies anterior to the goitre (arrow).
ligament sits posteriorly on the trachea, with the nerve close to the gland. erefore, carefully
trace and mobilize the gland o the nerve. With a high ligament, the nerve is oen laterally
placed and minimal dissection is required. Mainly on the right, 2% of nerves are not RLNs.
Pre-operative imaging identifying situs inversus or retro-oesophageal subclavian arteries
increases suspicion. A non-RLN runs inferomedially from the vagus nerve (Figure 85.3).
e integrity and function of the RLN can be assessed with intermittent intra-operative RLN
monitoring, which has been shown to avoid RLN injury.
Parathyroid Glands
e superior parathyroids normally lie posterior to the RLN, and inferior parathyroids lie
anterior. Carefully dissect them o the thyroid, preserving the blood supply. e superior
glands’ positions are relatively uniform. Inferior glands can be ectopic, due to their embryological path, and 1% of all parathyroids are intrathyroidal. If a parathyroid is excised or is
considered nonviable, auto-implantation into the SCM should be considered.
Pyramidal Lobe
Dissect the thyroid o the anterior tracheal wall and remove any pyramidal tissue. Le in
situ, it may reduce the ecacy of ablative radioiodine.
Head and Neck Endocrine Surgery 433
THYROIDECTOMY
Figure 85.3 Non-RLN arising directly from the right vagus nerve.
Closure
Wash out the thyroid bed.
•
Ensure haemostasis with Valsalva manoeuvres.
•
Check the RLN signal.
•
Prospective randomised controlled trials have demonstrated drains do not reduce
•
haematoma or seroma rates.
However, drainage may be considered in high-risk patients.
•
Approximate the strap muscles with one absorbable suture.
•
is prevents tracheo-cutaneous adhesions.
•
Allows a connection between the deep and supercial spaces, reducing the risk of
•
supraglottic oedema in the event of hematoma.
Approximate the platysma with absorbable sutures and meticulously close the skin.
•
Post-Operative Care
Position the patient with head up at 45°, allow patient to resume oral intake, and
•
mobilise as soon as possible.
Pharmacological venous thromboembolism prophylaxis in high-risk patients only.
•
Identication and management of potential hypocalcaemia:
•
Supplementation typically includes oral calcium carbonate (or intravenous calcium
•
gluconate if the patient has severe hypocalcaemia) and/or a vitamin D analogue
(typically alfacalcidol).
Each unit will have an algorithm to follow, but advice from endocrinologists should
•
be sought in challenging cases.
Etiology and Management of Goitre
Intrathoracic goitre usually extends into the right anterior mediastinum, because the
•
great vessels impede extension into the le.
10–15% grow into the posterior mediastinum.
•
Primary intrathoracic goitres are supplied by intrathoracic vessels.
•
Primary intrathoracic goitres represent <1% of all goitres, but up to 12% of all medi-
•
astinal tumours.
e risk of spontaneous intragoitre haemorrhage leading to acute respiratory compro-
•
mise is extremely low. With asymptomatic, euthyroid, benign cervical goitre, conservative management may be appropriate.
434 Head and Neck Endocrine Surgery
THYROIDECTOMY
In symptomat ic patients who decline or are unsuitable for surgery, radioiodine therapy
•
is an option. In 80% of patients, radioiodine reduces nontoxic goitre size by 30–45%
aer 1–2 years. is eect diminishes with goitre size and 10% will continue to grow.
131
I is inappropriate for compressive goitres because it can induce an acute increase in
size. Complications include radiation-induced thyroiditis, transient hyperthyroidism,
and long-term hypothyroidism (up to 58%).
Minimally Invasive and Robotic Thyroid Surgery
Introduction
Surgical scars are a signicant concern for patients. Of patients from a thyroid clinic who
were surveyed, 71% preferred an extracervical scar given the choice, and results were independent of sex and skin colour.
Minimally invasive thyroidectomy (MIT) is synonymous with minimally invasive videoassisted thyroidectomy (MIVAT) or Miccoli technique, endoscopic-assisted thyroidectomy
(EAT), and Henry technique. Radford’s meta-analysis demonstrated complications were no
higher than with conventional thyroidectomy and cosmetic outcomes were superior, but surgery was more time consuming.
Miccoli Technique
A 2- to 3-cm midline incision facilitates endoscopic dissection of the superior pole, with
completion thyroidectomy performed once the thyroid is delivered.
Advantages:
No complications from insuation
•
Total thyroidectomy (TT) is possible
•
Excellent visualisation of nerves and parathyroids
•
Disadvantages:
Requires two assistants and video stacks
•
Limited by the lesion (solitary nodules ≤3 cm, total thyroid lobe ≤20 mL)
•
Steep learning curve
•
Unsuitable for thyroiditis, cancer, or re-operative surgery
•
Henry Technique
ree ports are created along the anterior border of the SCM, two for instrumentation and
one for the CO2 insuator endoscope. Dissection takes places intracervically and the thyroid is delivered through the endoscope port. Indications replicate those for the Miccoli
technique, but TTs are not possible.
Extracervical Techniques
Axillo-bilateral-breast and bilateral axillo-breast approaches were pioneered in the Far East.
Although the techniques are technically demanding, total thyroid lobectomy (TL) and TT
can be achieved safely.
Robotic-Assisted Thyroidectomy (RAT )
Data support superior cosmetic outcomes, better post-operative swallowing function
than with conventional thyroidectomy, and safety with thyroid microcarcinomas (<1 cm).
Investigation into the safety in treating thyroid cancers >1 cm is required.
Risks of bleeding, infection, vocal cord palsy, parathyroid dysfunction, inpatient stay, and
time o work are equal to those for conventional thyroidectomy. However, RAT can potentially cause brachial plexus dysfunction. Airway obstruction does not occur following
RAT because blood can disseminate in a larger space than is available aer conventional
thyroidectomy.
Head and Neck Endocrine Surgery 435
SURGERY FOR METASTATIC AND LOCALLY ADVANCED THYROID CANCER
Indications:
Nodules ≤6 cm for TL
•
TT, provided the contralateral lobe is near normal
•
Contraindications:
BMI >30
•
Degenerative shoulder pathology
•
ASA >2
•
KEY POINTS
• Surgery (TL/TT +/− central and/or lateral neck dissection) is the mainstay of thyroid
cancer management, accompanied by adjuvant therapies (
radiotherapy).
• Surgery is performed on goitre to manage:
• compressive/obstructive symptoms
• thyroid overactivity
• cancer or suspicious goitre
• For large retrosternal goitres, for those with mediastinal extrathyroidal extension, or
for those with primary intrathoracic goitre, cardiothoracics should be involved.
• With posterior mediastinal goitre, the RLN may pass anterior to the thoracic portion of
the goitre.
• If parathyroid glands are excised or considered nonviable, consider auto-implantation
into the SCM muscle.
Further Reading
Chang EHE, Kim HY, Koh YW, Chung WY. Overview of robotic thyroidectomy. Gland Surg
2017; 6(3): 218–228.
Hobbs CGL, Watkinson JC. yroidectomy. Surgery (Oxford), 2007; 25(11): 474–478.
Randolph GW, Clark OH. Principles in thyroid surgery. In: Surgery of the yroid and
Parathyroid Glands, 2
86. SURGERY FOR METASTATIC AND LOCALLY ADVANCED
nd
edition. Philadelpia: Elsevier Saunders; 2012
THYROID CANCER
131
I +/− external beam
Introduction
Dierentiated thyroid cancer (DTC) has an excellent prognosis. Nonetheless, tumour
breaching the thyroid capsule may be more challenging. Treatment should be preceded by
discussion at an appropriately constituted multidisciplinary team (MDT) meeting. Surgery
is the main treatment modality for both primary and recurrent disease.
Risk stratication, particularly aer primary index surgery, is important in managing risk of
locoregional recurrence, which is oen predictable.
Patients with residual disease frequently live many years with minimal symptoms. Balancing
complication morbidity with the natural history of the disease requires a personalised
approach that considers the patient’s age and the tumour biology. A balanced decision on
treatment is important in the paradigm of patient care.
436 Head and Neck Endocrine Surgery
SURGERY FOR METASTATIC AND LOCALLY ADVANCED THYROID CANCER
Advanced Thyroid Cancer
Surgical management of advanced thyroid cancer includes:
Extrathyroidal spread (ETE)
•
Recurrent or residual disease in the thyroid bed and neck
•
Extracapsular nodal disease
•
Surgery for distant metastases
•
Extrathyroidal Spread
Cancer breaching the thyroid capsule is associated with increased morbidity and mortality.
ETE is present in 25% of patients and varies between minimal extension into surrounding
strap muscles (T3) to invasion of the larynx, recurrent laryngeal nerve, oesophagus, and
prevertebral muscles (T4a/b). Residual disease can result in local recurrence, and disease
clearance is associated with improved survival.
Factors associated with an increased risk of extracapsular spread include:
Older patients
•
Larger tumours (>4 cm)
•
Advanced nodal disease
•
Presence of distant metastases
•
Voice a nd swa llowing sy mptoms necessitate appropriate clinical and radiologic al assessment.
Examination of the vocal cords is mandatory, and for large tumours, cross-sectional imaging
by contrast-enhanced computed tomography (CT) is strongly recommended. Tracheoscopy
and oesophagoscopy may be selectively required before primary index surgery. Pathological
factors associated with a higher risk of ETE include insular, tall cell, and undierentiated
subtypes of thyroid cancer.
Involvement of Nonvital Structures Around the Thyroid Bed
If ETE involves strap muscles only, simple excision produces no morbidity.
Involvement of the Recurrent Laryngeal Nerve
In up to 60% of locally advanced disease, the recurrent laryngeal nerve (RLN) can be
involved. Radiology cannot predict involvement in the functioning RLN, but it aids discussion for informed consent related to the likelihood of nerve injury, resection, and the need
for reconstruction.
In an ipsilateral cord palsy with the nerve encased in tumour, resection is advised, with primary reconstruction if feasible. With a functioning nerve, particularly in the young patient
(<55 years old), nerve resection is not advised, because the morbidity and mortality from a
nerve palsy counterbalance those of the index disease.
If both nerves are functional but involved with disease, or if one nerve is involved in a preexisting contralateral palsy, nerve preservation to avoid tracheostomy is advised.
Involvement of the Trachea and Larynx
Up to 50% of mortality from DTC is due to direct invasion of the airway. However, the
prognosis for those with locoregional recurrence is better than that for distal disease. When
locoregional control is achieved, disease-specic mortality arises from metastatic tumour
burden.
Intraluminal tumour extension is fundamental to surgical planning, and when it is suspected, laryngoscopy and tracheoscopy are mandatory. Although poorly sensitive, contrastenhanced CT is specic in detecting airway invasion. Magnetic resonance imaging (MRI)
may also help dene disease if laryngeal cartilage invasion is present.
If there is supercial invasion of the trachea with no intraluminal extension, tracheal
shaving is sucient. In the trachea, local control rates as high as 95% have been reported
Head and Neck Endocrine Surgery 437
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