Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_4385_Библиотеки_им_академика_М_И_Перельмана
.pdf
BENIGN THYROID DISEASE
Table 81.4 Causes of nodular thyroid enlargement
Malignant
Benign
Follicular adenoma Papillary carcinoma Thyroid lymphoma
Hürthle cell adenoma Follicular carcinoma Malignancy metastatic to the thyroid
Colloid cyst Hürthle cell carcinoma
Simple/haemorrhagic cyst Medullary thyroid carcinoma
Lymphocytic thyroiditis Anaplastic carcinoma
Granulomatous thyroiditis
Infectious processes
yroid enlargement because of malignancy is indistinguishable from benign causes in
many cases.
Investigations
See Chapter 80.
Management
For benign goitre, surgery is indicated for compressive symptoms.
Lobectomy is used when only one lobe is severely aected.
•
Total thyroidectomy is appropriate if the gland is diusely involved.
•
Rarely, sternotomy is required for retrosternal goitre.
•
Follicular or C-cell origin Malignancy of other origin
Radioiodine is an option in patients who refuse surgery or if age, frailty, or comorbidities
preclude operative intervention.
For the solitary nodule, hemithyroidectomy is indicated for suspected malignancy or
cosmesis.
yroid cysts, found in 10–15% of patients presenting with a thyroid nodule, are usually
benign. Most resolve over time. yroid lobectomy is performed for symptomatic recurrent
cysts, cysts associated with a solid nodule, or those with rapid nodular growth.
KEY POINTS
• Pre-operative preparation of the hyperthyroid patient is vital to prevent post-operative
thyroid storm and should be managed in conjunction with an endocrinologist.
• All thyroid nodules over 1 cm should have assessment by ultrasound and FNAC.
• Surgery for benign disease is indicated for compressive symptoms, suspicion of
malignancy, and cosmesis and for those who have contraindications to medical
treatment of hyperthyroidism.
• Total thyroidectomy is required for thyrotoxic patients who fail medical management.
• A multidisciplinary team including an endocrinologist, an obstetrician, and a pediatrician
should manage patients with thyroid disease in pregnancy.
Further Reading
1. Patel KN, Yip L, Lubitz CC, Grubbs EG, Miller BS, Shen W, et al. e American
Association of Endocrine Surgeons guidelines for the denitive surgical management
of thyroid disease in adults. Ann Surg 2020 Mar; 271: e21–e93.
2. yroid disease: assessment and management. NICE Guideline, 2019.
418 Head and Neck Endocrine Surgery
MANAGEMENT OF DIFFERENTIATED THYROID CANCER
82. MANAGEMENT OF DIFFERENTIATED THYROID CANCER
Dierentiated thyroid cancer (DTC), including the papillary and follicular subtypes, has an
excellent prognosis, with 10-year survival rates exceeding 98% in stage I–III disease. TNM
staging is used for classication (Table 82.1).
Surgery is the most common primary treatment, with some patients requiring adjuvant
treatment, most frequently radioiodine ablation with TSH suppression. Individualised treatment has been introduced in recent years, to take into consideration patient and tumour
factors and risk of recurrence.
Patients with thyroid cancer require a detailed clinical history, including previous radiation exposure and family history of thyroid cancer and Hashimoto’s disease. Ultrasound
scan and ne-needle aspiration cytology (FNAC) obtain the diagnosis in most cases. Crosssectional imaging with computed tomography (CT) or magnetic resonance imaging (MRI)
may be required to further assess locoregional disease (Table 82.2).
Thyroidectomy
yroidectomy is the mainstay of treatment in DTC.
A total thyroidectomy is recommended for patients with:
Tumours >4 cm, bilateral disease
•
Extrathyroidal spread or metastatic disease
•
Adverse histopathological features
•
Familial types of DTC
•
History of radiation exposure
•
For patients with smaller tumours and no poor prognostic features, a hemithyroidectomy
will suce, but preoperative discussion in a thyroid cancer multidisciplinary team meeting
is advised.
During surgery, if recurrent laryngeal nerve (RLN) involvement is encountered, the surgeon
should aim to preserve the nerve if it was functioning pre-operatively. It is acceptable to
leave a small amount of disease to preserve laryngeal function because no survival benet is
gained by RLN sacrice. Tracheal or oesophageal involvement leads to a signicant decrease
in survival and may require partial resection. Cross-sectional imaging should be carefully
examined pre-operatively.
Table 82.1 TNM staging for differentiated thyroid cancer
Age at diagnosis < 55 years
Stage I Any T Any N M0
Stage II Any T Any N M1
Age at diagnosis ≥ 55 years
Stage I T1 N0 / NX M0
T2 N0 / NX M0
Stage II T1 N1 M0
T2 N1 M0
T3a/T3b Any N M0
Stage III T4a Any N M0
Stage IVA T4b Any N M0
Stage IVB Any T Any N M1
Head and Neck Endocrine Surgery 419
MANAGEMENT OF DIFFERENTIATED THYROID CANCER
yroid hormone replacement is required if there is an endogenous deciency, to prevent
stimulation of any remaining thyroid tissue and to reduce recurrence in high risk cases. TSH
suppression is usually reserved for higher-risk cases.
Papillary Thyroid Carcinoma (PTC)
Papillary thyroid microcarcinoma (PTMC) is dened as PTC no greater than 1 cm in size.
PTMC is rarely identied pre-operatively due to patient symptoms.
•
PTMC tends to present incidentally during radiological examination.
•
Post-operatively, PTMC can be identied during histological assessment.
•
In some centres, monitoring is oered without active treatment.
•
ese patients have an excellent prognosis following hemithyroidectomy. Cases identied on
histological assessment are discharged without follow-up, whereas pre-operatively identied
cases are monitored for 5 years because they may be higher risk. Any patient who has PTMC
with aggressive features should be managed in the same way as a patient with non-low-risk PTC.
e majority of patients undergoing surgery for follicular thyroid cancer will be undiagnosed at the time of the initial surgery (y 3). Frozen-section histology cannot currently
reliably dierentiate benign follicular lesions from follicular thyroid cancer; therefore, a
diagnostic lobectomy is recommended.
Low-risk patients with a diagnosis of minimally invasive tumour (<4 cm) do not require
further treatment aer hemithyroidectomy. Hürthle cell cancer (follicular oncocytic thyroid
cancer) tends to be more aggressive a nd should be treated by tota l (completion) thyroidec tomy
Management of Cervical Lymph Node Metastasis in DTC
In the presence of nodal disease, a compartment-oriented neck dissection is recommended,
with dissection of Level VI for central disease and Levels IIa–Vb for lateral neck disease.
In DTC >4 cm and in patients with extrathyroid extension but without evidence of nodal
disease, prophylactic central neck dissection should be considered—but there is no conclusive evidence of benet. Involvement of Level I or VII nodes is rare in DTC, and these nodes
should be dissected only if they are involved. Prophylactic lateral neck compartment dissection for node-negative patients is not recommended; however, ipsilateral Level VI dissection
is advised in pre-operatively diagnosed PTC without imaging evidence of nodal disease, as
Level VI ultrasound assessment is inaccurate.
Radioiodine
Radioiodine,
ectomy has been performed or for treatment of residual, recurrent, or metastatic disease.
RRA may improve survival, reduce recurrence, and allow more eective monitoring with
thyroglobulin in the long term.
Radioiodine is administered orally. Prior to administration, the total body iodine pool is depleted
with a 2-week low-iodine diet and the TSH level is elevated by stopping thyroid hormone replacement; these steps encourage radioiodine uptake into thyrocytes. Administration of radioiodine
requires care on an isolation ward and avoidance of contact with people for 14–25 days aer treatment. ere are short-term implications for pregnancy, breastfeeding, and fertility.
e indication for radioiodine has undergone radical change recently, and cases should be
discussed on an individual basis in the thyroid cancer multidisciplinary setting. RRA is
indicated in patients with tumours >4 cm and in those with gross extrathyroidal spread or
distant metastasis. RRA is not indicated in patients with low-risk tumours. e intermediate
group require discussion, and those with poorer prognostic features could be oered RRA.
Higher treatment doses are recommended in patients with gross residual disease aer initial
surgery (R2 resection) in an adjuvant setting. Patients who develop distant metastases or who
present with radioiodine-avid inoperable disease may receive therapeutic radioiodine, which
420 Head and Neck Endocrine Surgery
131
I, can be used for radioiodine remnant ablation (RRA) when a total thyroid-
MANAGEMENT OF DIFFERENTIATED THYROID CANCER
can be repeated at 6- to 12-month intervals. An iodine scan 2–10 days aer treatment allows
assessment of radioiodine uptake in the neck and elsewhere.
Radioiodine can cause toxicity, which is generally mild and short-term. Early toxicity includes
local reaction in the neck (especially if there is residual thyroid tissue), sialadenitis, xerostomia,
gastroi ntestinal eects, bone marrow suppression, and lacrimal dysfunction. Late complications
can include permanent bone marrow suppression, pulmonary brosis, and secondary cancers.
External-Beam Radiotherapy (EBRT)
EBRT may be used in patients with evidence of gross tumour invasion at surgery, in patients
with residual or recurrent tumours that are not radioiodine avid, and for palliation of inoperable metastatic disease. Intensity-modulated radiotherapy (IMRT) reduces the dose to
radiosensitive areas and allows better dose distribution to the target. Common toxicities
include mucositis, skin erythema, skin desquamation, and laryngitis. Radiotherapy may
reduce uptake of radioiodine into residual thyroid tissue.
Chemotherapy
No data are available to support adjuvant chemotherapy agents in the management of DTC,
and it is not routinely used in recurrent or metastatic disease.
Targeted Therapies
Targeted treatments are indicated for patients with progressive, locally advanced, metastatic
DTC (papillary, follicular, Hürthle cell), refractory to conventional treatments (such as surgery or RRA). e tyrosine kinase inhibitors sorafenib and lenvatinib have demonstrated the
greatest clinical benet to date.
Assessing Treatment Outcome
Evaluation of eectiveness of treatment is undertaken 9–12 months aer treatment using
stimulated thyroglobulin (TG) measurements and ultrasound scanning. When assessed
together, these are more accurate than radioiodine scanning.
TG is used as a tumour marker to assess treatment response (following total thy-
•
roidectomy and radioiodine therapy) and potential recurrence. It is a key substrate
for biosynthesis and storage of thyroid hormones. Its release from both normal and
malignant thyroid cells is TSH-dependent. If it is found to be increasing in a patient
previously treated for thyroid cancer, it may indicate recurrence or metastases.
Stimulated TG allows assessment of disease activity but can only be used in the
•
absence of TG antibodies (TGAb). TG and TGAb are measured aer a TSH increase
induced by either recombinant TSH injection or thyroxine withdrawal.
Disease-free status can be predicted with 98–99% accuracy if stimulated TG is <0.5 mcg/L.
A result of >2 mcg/L predicts persistent disease. Unstimulated TG can also be measured in
low-risk patients, and a result of <0.1 mcg/L in the absence of TGAb, along with a negative
ultrasound, has a high negative predictive value.
Cross-sectional imaging is only indicated where post-radioiodine-ablation scan shows uptake
beyond the neck, or serum TG is unreliable.
Follow-Up
Low-risk patients managed with hemithyroidectomy may be monitored using neck ultrasound. For patients having undergone total thyroidectomy and RRA, ultrasound neck imaging and stimulated TG should be performed 9–12 months aer RRA. Groupings of three
treatment outcomes can be identied using dynamic risk stratication: patients with an
excellent response, patients with equivocal or indeterminate response, and those with persistent disease (Table 82.3).
Head and Neck Endocrine Surgery 421
MANAGEMENT OF DIFFERENTIATED THYROID CANCER
e excellent responders are patients who have been treated with surgery and RRA and at
follow-up have a stimulated TG <1 mcg/L and a negative ultrasound scan. is group can
undergo annual TG assessment, and their TSH should be maintained in the low-normal range.
Aer 5 years, if they remain disease-free, they can be followed up in a less intensive clinic.
e equivocal or indeterminate group (those with stimulated TG of 1–10 mcg/L and nonspecic ultrasound changes) should be closely monitored with serial stimulated TG and ultrasound assessment. It is prudent to detect recurrence early. Low TSH should be maintained
for 5–10 years.
e persistent disease group are those with rising TG, stimulated TG >10 mcg/L, or an
ultrasound scan indicating local recurrence. Imaging to investigate the site of recurrence,
such as FDG PET-CT or
treatment, TSH suppression to <0.1 mU/L indenitely and close follow-up are indicated.
Lifelong follow-up is indicated because DTC has a long natural history, late recurrences
can occur, radioiodine can cause late side-eects, and supraphysiological thyroid hormone
replacement can result in conditions that require monitoring.
Recurrence
Higher rates of recurrence are found in patients with
Locally advanced disease or bulky nodal metastases
•
Macroscopic extrathyroid extension
•
Aggressive histological subtypes
•
PTC relapse occurs in 5–20% of patients and usually aects the thyroid bed or cervical
lymph nodes.
When TG is detectable, imaging is utilised to localise the disease recurrence and to target it
with further treatment.
For patients in whom extensive imaging fails to identify a site of recurrent disease, management involves continued monitoring until the site is symptomatically apparent or imaging
identies recurrence or treatment with empirical
e aim of treatment is to surgically remove recurrent disease and to prevent further recurrence, but morbidity and impact on quality of life should be considered.
Lymph node recurrence may be monitored if it is small-volume and distant from the
•
nerve and airway.
Rapid enlargement or proximity to important central neck structures should prompt
•
a more aggressive approach.
yroid bed recurrence can present a signicant challenge for further surgical resec-
•
tion. If complete resection is not possible, debulking can be benecial to facilitate
greater radioiodine uptake in the smaller residual volume. Distant metastases occur
in 10–20% of cases, with pulmonary and bone spread accounting for the majority.
Radioiodine-avid disease can be managed with repeat doses of radioiodine, and
remission can be achieved in about one third of patients with distant metastases.
131
I scan, is indicated if the ultrasound scan is negative. Aer further
131
I therapy.
KEY POINTS
• An individualised approach to treatment for DTC is now the mainstay, taking into
consideration patient and tumour factors and risk of recurrence.
• Surgery continues to be the rst-line management in thyroid cancer.
• All thyroid cancer patients should be discussed in the multidisciplinary setting.
• Radioiodine remnant ablation and therapy doses should be personalised, depending
on patient and tumour factors.
• Biochemical evaluation and ultrasound imaging detect most recurrences.
422 Head and Neck Endocrine Surger y
MANAGEMENT OF MEDULLARY THYROID CANCER
Further Reading
American yroid Association Management Guidelines for Adult Patients with yroid
Nodules and Dierentiated yroid Cancer, 2016.
British yroid Association Guidelines for Management of yroid Cancer, 2014.
Haugen BRM, Alexander EK, Bible KC, Doherty G, Mandel SJ, Nikiforov YE, et al. American
yroid Association Management Guidelines for Adult Patients with yroid Nodules
and Dierentiated yroid Cancer. yroid 2016; 26:1–133.
Mitchell AL, Gandhi A, Scott-Coombes D, Perros P. Management of yroid Cancer:
United Kingdom National Multidisciplinary Guidelines. J Laryngol Otol 2016; 130(S2):
S150 –S160.
Perros P, Boelaert K, Colley S, Evans C, Evans RM, Gerrard Ba G, et al. Guidelines for the
Management of yroid Cancer. Clin Endocrinol (Oxf) 2014; 81(Suppl 1): 1–122.
UK National Multidisciplinary Guidelines: Management of yroid Cancer, 2016.
83. MANAGEMENT OF MEDULLARY THYROID CANCER
Incidence
Medullary thyroid cancer (MTC) is diagnosed in approximately 1,000 people each year in
the United States and 25–50 people in the United Kingdom. It constitutes 5–10% of paediatric thyroid cancers.
Pathology
MTC is a neuroendocrine tumour arising from parafollicular C cells. C cells are of neural
crest origin and produce calcitonin, calcitonin gene-related peptide (CGRP), and carcinoembryonic antigen (CEA).
C-Cell Hyperplasia
C-cell hyperplasia (CCH) is dened as a multifocal, quantitative increase in C cells. CCH can
be neoplastic or reactive/physiological.
MTC
Sporadic tumours are usually solitary (90%) and unilateral. In familial disease, MTC is usually bilateral and multifocal. Variants of classical MTC include papillary, follicular, squamous, and oncocytic subtypes.
Genetic Basis of MTC
Genetically determined disease accounts for 25% of MTC cases, and its prevalence is
estimated at 1 in 30,000. e three main clinical variants are all inherited as autosomal
dominant disorders with 100% risk of developing MTC:
Multiple endocrine neoplasia type 2A (MEN 2A): >50% of cases, associated with
•
phaeochromocytoma and hyperparathyroidism
Multiple endocrine neoplasia type 2B (MEN 2B): 5% of cases, biologically the most
•
aggressive, with the highest propensity for metastasis, associated with phaeochromocytoma, marfanoid habitus, and ganglioneuromas
Familial medullary thyroid cancer (FMTC): only MTC
•
Head and Neck Endocrine Surgery 423
MANAGEMENT OF MEDULLARY THYROID CANCER
Gain of function germline and somatic mutations of the RET proto-oncogene (chromosome
10q11.2) are implicated in the pathogenesis of MTC. RET encodes a plasma membranebound receptor-type tyrosine kinase that is expressed by thyroid C cells, cells of the adrenal
medulla, autonomic nerve ganglia, colonic ganglia, and parathyroid cells.
Clinical Features of Sporadic and Hereditary MTC
Presentation:
Sporadic MTC: fourth to sixth decade
•
MEN 2A: rst decade
•
MEN 2B: rst and second decades
•
FMTC: adulthood
•
Almost equal sex ratio
•
A thyroid mass is normally the rst indication of disease (>75%), and cervical lymphadenopathy is a presenting feature in approximately 40–50% of patients. Around 10% of patients
will have distant metastases.
Diagnosis of MTC
Fine-needle aspiration cytology (FNAC) produces a diagnosis in 50% of cases, and when it
is coupled with calcitonin assays, it increases sensitivity and specicity for MTC diagnosis.
Targeted core-needle biopsy avoids the need for open biopsy.
Routine measurement of basal calcitonin in patients presenting with nodular thyroid disease
is not recommended by the British yroid Association.
Pre-Operative Investigations
Calcitonin and CEA
Serum calcitonin is a sensitive and accurate marker of MTC and should be measured in MTC
patients pre-operatively because it can indicate disease extent. Lymph node involvement may be
found in patients with calcitonin as low as 10–40 pg/mL; distant metastasis and extrathyroidal
growth can be indicated by calcitonin levels of 150–400 pg/mL. False-positive serum calcitonin
levels are recorded in patients with autoimmune t hyroid disease, hypercalc aemia, foregut-derived
neuroendocrine tumours, and renal failure. e positive predictive value of an abnormal basal
calcitonin greater than 100 pg/mL is 100%. CEA should be measured in all patients with MTC.
Urinary or Plasma Catecholamines/Metanephrines
Biochemical testing for phaeochromocytoma (24-hr urine, or plasma free metanephrines
and normetanephrines) is mandatory prior to surgery in all patients with a diagnosis of MTC.
Phaeochromocytoma should be treated before treatment of the thyroid disease.
Calcium
Serum calcium and PTH levels should be obtained pre-operatively. Hypercalcaemia or inappropriate serum PTH will indicate the need for careful assessment of the parathyroid glands
at the time of thyroidectomy and excision of enlarged glands.
Ret Mutation Analysis
RET mutation and genetic testing should be performed in all patients diagnosed with MTC,
as they may represent the index case of a previously undiagnosed MEN kindred.
When a patient with MTC is identied as carrying a RET mutation, genetic screening should
be oered to rst-degree relatives. Family members identied as gene-positive can be oered
therapeutic, risk-reduction, or prophylactic surgery for MTC (see below).
Imaging
A neck ultrasound can identify the extent of the tumour and cervical lymph node metastasis.
Cross-sectional computed tomography (CT) of the neck, chest, and abdomen is essential to
424 Head and Neck Endocrine Surgery
MANAGEMENT OF MEDULLARY THYROID CANCER
Table 83.1 Medullary thyroid cancer staging
Stage I T1a, T1b N0 M0
Stage II T2, T3 N0 M0
Stage III T1, T2, T3 N1a M0
Stage IVA T1, T2, T3, T4a N1b, Any N M0
Stage IVB T4b Any N M0
Stage IVC Any T Any N M1
assess extrathyroidal spread into the trachea or oesophagus, mediastinal lymphadenopathy, phaeochromocytomas, and distant metastasis. e liver is the commonest site of distant
metastasis. A high calcitonin (>400 pg/mL) is associated with distant metastasis.
Staging
MTC is classied according to the TNM staging system (Table 83.1).
Surgery for MTC
Depending on the MTC stage, a total thyroidectomy and selective neck dissection are
required in most patients.
e aims of surgery are:
Remove all disease in the neck
•
Produce biochemical and clinical cure
•
Minimise the risk of locoregional relapse that might compromise the airway, oesopha-
•
gus, or recurrent laryngeal nerves
Rationale for Lymph Node Dissection in MTC
Node metastases are common (>75%) in patients with palpable MTC, occurring early
•
and in medullary microcarcinoma (<1 cm).
Ipsilateral lateral neck nodes may be involved in over 80% of cases and contralateral
•
lateral nodes in over 50% of cases.
Approximately 20% of patients will have skip metastases (negative central compart-
•
ment and positive lateral or mediastinal compartments).
Positive cervical nodes and extrathyroidal extension increase the risk of mediastinal
•
and distant metastases.
A reasonable approach to the primary surgical treatment of MTC without distant metastases
includes the following:
Procedure Indication
Total thyroidectomy and central compartment
neck dissection
Above + Ipsilateral Level IIa–Vb selective neck
dissection
Mediastinal lymph node dissection
(thoracotomy)
Completion thyroidectomy is not required in incidental micro MTC <5 mm (RET-negative)
with normal post-operative basal calcitonin.
• MTC greater than 5 mm
• RET-positive family members
• Known distant metastases at diagnosis (to
reduce disease burden)
Ipsilateral lymph node involvement
Positive central neck nodes (which imply 70%
risk of ipsilateral metastasis and 35% risk of
contralateral nodal metastasis)
Infrabrachiocephalic mediastinal nodal disease
and no evidence of distant metastases
Head and Neck Endocrine Surgery 425
MANAGEMENT OF MEDULLARY THYROID CANCER
Surveillance
MTC requires lifelong follow-up with a combination of serum calcitonin, CEA, and neck
ultrasound. Specialist thyroid cancer multidisciplinary team input is required.
Post-operative monitoring includes the following considerations:
If serum calcitonin is undetectable and CEA is normal at 2 months, consider annual
•
calcitonin and CEA (and biochemical screening for primary hyperparathyroidism
and phaeochromocytoma for MEN 2A/2B, namely serum calcium, PTH, and plasma
free normetanephrines and metanephrines).
If calcitonin is detectable and CEA is abnormal, the patient requires a neck ultra-
•
sound to look for structural evidence of disease. If there is no structural disease, measure calcitonin/CEA every 3 months to check doubling times and examine with neck
ultrasound every 6 months. If there is structural evidence of disease, locoregional or
systemic therapy should be considered (see the section on adjuvant therapy below).
Persistent/Recurrent Hypercalcitonainemia and Recurrent MTC
Residual/recurrent disease is diagnosed (usually within the rst 5 years) on the basis of
clinical symptoms, signs, or an elevated/rising calcitonin or CEA. Radiological evidence of
metastases is best detected when serum calcitonin levels are greater than 800 pg/mL.
Consider:
Was the initial surgery less than that recommended according to best practice?
•
Is the source of calcitonin in the neck (residual thyroid or lymph nodes) or in the
•
mediastinum?
Will further surgery result in cure or improved survival?
•
Surgery aims to cure or signicantly reduce the disease bulk as well as to relieve or prevent
future compression of surrounding structures. e presence of distant disease should not in
isolation preclude surgery.
Outcome and Prognosis
10-year survival range is 56–96%.
•
Biochemical cure aer surgery is associated with a 97.7% survival at 10 years.
•
Children with MTC have 5-year survival rates of 95%.
•
Rate of 6-month post-thyroidectomy calcitonin/CEA doubling correlates with prog-
•
nosis (<1 year is poor, >2 years is better).
Adjuvant Therapy
External-beam radiotherapy can reduce local relapse in high-risk patients and in those with
advanced disease. ere is no survival benet. It should be considered for controlling local
symptoms in patients at high risk of locoregional recurrence or with inoperable disease.
Clinical benet from the use of tyrosine kinase inhibitors, such as vandetanib and cabozantinib, is seen in over half of patients with progressive/metastatic MTC. Toxicity is considerable and side eects are common.
Risk Reduction Surgery for Hereditary MTC
Timing of Thyroidectomy
e timing of the intervention and the extent of surgery should be based on the aected RET
codon, the age of the patient, and the calcitonin level.
Children with RET codon 918 and 883 mutations (MEN 2B) should have prophylactic
•
thyroidectomy performed within the rst year of life, preferably in the rst 6 months.
Children with a RET codon 634 mutation have a high risk for MTC in the rst decade.
•
Prophylactic thyroidectomy should be performed at 5 years of age, or earlier if the
calcitonin level is elevated above 40 pg/mL.
426 Head and Neck Endocrine Surgery
MANAGEMENT OF ANAPLASTIC THYROID CANCER AND LYMPHOMA
Children with other RET codon mutations should undergo clinical examination
•
every 6 months, with measurement of serum calcitonin and neck ultrasound until age
5 years. yroidectomy may be delayed until later in childhood or the teenage years if
calcitonin levels do not rise above the normal range.
Need for, and Timing of, Lymph Node Surgery
Risk-reduction surgery should be performed before the onset of MTC to reduce the need for
lymph node dissection.
Children from a known RET kindred with highest-risk mutations (codons 918, 883)
•
should be considered for lymph node dissection at the time of surgery.
Children with MEN 2A with a mutation of codon 634 should undergo central neck
•
dissection at the time of surgery if the calcitonin level is greater than 40 pg/mL or if
there is evidence of nodal metastasis on imaging.
KEY POINTS
• MTC care should be provided by a specialist multidisciplinary thyroid cancer service.
• Preoperative investigations must include serum calcitonin, CEA, plasma free
normetanephrines and metanephrines, serum calcium, and parathyroid hormone.
• All MTC patients should be offered RET gene mutation analysis. In conrmed cases of
genetically determined disease, rst-degree relatives should be offered genetic screening.
• Staging should include cross-sectional CT imaging of the neck, chest, and abdomen.
• Risk-reduction/prophylactic surgery should be offered to RET-positive family members.
• A phaeochromocytoma should be excised prior to MTC treatment.
• Patients with MTC and an elevated basal calcitonin should undergo at least a total
thyroidectomy and central neck lymph node dissection.
• MTC requires lifelong follow-up.
Further Reading
Ceolin L, Duval M, Benini AF, Ferreira CV, Maia AL. Medullar y thyroid carcinoma beyond sur-
gery: advances, challenges, and perspectives. Endocr Relat Cancer 2019 ; 26(9): R499–R518.
Maia, AL, Wajner SM, Vargas CV. Advances and controversies in the management of medul-
lary thyroid carcinoma. Curr Opin Oncol 2017; 29(1): 25–32.
Wells, SA Jr, Asa, SL, Dralle H, Elisei R, Evans DB, Gagel RF, Lee N, Machens A, Moley JF,
Pacini F, Raue F, Frank-Raue K, Robinson B, Rosenthal MS, Santoro M, Schlumberger
M, Shah M, Waguespack SG, American yroid Association Guidelines Task Force on
Medullary yroid Cancer. Revised American yroid Association guidelines for the
management of medullary thyroid carcinoma. yroid 2015; 25(6): 567–610.
84. MANAGEMENT OF ANAPLASTIC THYROID CANCER AND LYMPHOMA
Introduction
Anaplastic thyroid cancer and thyroid lymphoma are two rare malignancies of the thyroid
gland. ey are similar in that for most patients, surgery is limited to diagnosis and airway
management. Unfortunately, most anaplastic thyroid cancers present at an advanced stage
with complete surgical resection impossible. In the majority of thyroid lymphomas, surgery
is not curative, and radiotherapy with or without chemotherapy is the optimum treatment.
Head and Neck Endocrine Surgery 427
Соседние файлы в папке Библиотека им академика М.И. Перельмана