Transcript Thyroiditis – inflammation of the thyroid gland

THYROID CANCER
Thyroid Cancer Type and
Incidence
 Papillary ~ 60-75%
 Follicular ~20-30%
 Medullary ~ 5-10%
 Anaplastic ~ 3%
KEY POINTS
Thyroid cancer is the most common
malignancy of the endocrine glands.
The great majority of cancers of the
follicular thyroid epithelium are welldifferentiated (papillary and
follicular) and have a good prognosis,
particularly in young patients.
KEY POINTS
Thyroid Ca is one of the most
curable cancers.
The incidence of thyroid Ca in
thyroid nodules ranges from
0.5% to 10%.
ETIOPATHOGENESIS
ONCOGENES:
– gene rearrangements RET/PTC
(papillary Ca)
– mutations of the ras gene family (an
early event in thyroid tumorigenesis)
– inactivating mutations of the p53
tumor-suppressor gene
(undiffereniated thyroid Ca)
ETIOPATHOGENESIS
External irradiation of the neck
(the latency period is at least 5 years)
Iodine deficiency (Follicular Ca)
PAPILLARY CANCER
The Most Common Thyroid Cancer
Peak onset ages 30 through 50
Females more common than males by 3
to 1 ratio
Prognosis directly related to tumor size
[less than 1.0 cm - good prognosis]
Accounts for 85% of thyroid cancers
due to radiation exposure
PAPILLARY CANCER
Spread to lymph nodes of the neck
present in more than 50% of cases
Distant spread (to lungs or bones) is
very uncommon
Overall cure rate very high
(near 100% for small lesions in young
patients)
MANAGEMENT OF PAPILLARY
THYROID CANCER
Papillary carcinomas that are well
circumscribed, isolated, and less than
1cm in a young patient (20-40)
without a history of radiation
exposure may be treated with
hemithyroidectomy and
isthmusthectomy.
MANAGEMENT OF PAPILLARY
THYROID CANCER
All others should be treated with
total thyroidectomy and removal
of any enlarged lymph nodes in
the central or lateral neck areas.
MANAGEMENT OF PAPILLARY
THYROID CANCER AFTER
SURGERY
Since papillary cancer may
respond to TSH, thyroid hormone
is given in doses large enough to
suppress secretion of TSH and
help prevent a recurrence.
MANAGEMENT OF PAPILLARY
THYROID CANCER AFTER
SURGERY
Serum FT3 i FT4 should be in the
normal range to avoid iatrogenic
thyrotoxicosis
Serum Tg, a marker of cell function,
increases dramatically during
hypothyroidism, while it returns to
low levels during hormone therapy
MANAGEMENT OF PAPILLARY
THYROID CANCER AFTER
SURGERY
 Papillary cancer cells absorb
iodine and therefore they can
be targeted for death by giving
the toxic isotope (I-131).
MANAGEMENT OF PAPILLARY
THYROID CANCER AFTER
SURGERY
 In patients with larger tumors, spread
to lymph nodes or other areas, tumors
which appear aggressive
microscopically, radioactive iodine is
often given in expectation that any
remaining thyroid tissue or cancer
that has spread away from the thyroid
will take it up and be destroyed.
PAPILLARY THYROID CANCER
LONG-TERM FOLLOW UP
 A yearly chest X-ray
 Thyroglobulin levels
a high serum thyroglobulin level that had
previously been low following total
thyroidectomy especially if gradually
increased with TSH stimulation is virtually
indicative of recurrence.
A value of greater than 10 ng/ml is often
associated with recurrence even if an iodine
scan is negative.
FOLLICULAR CANCER
THE SECOND MOST COMMON THYROID
CANCER
 Peak onset ages 40 through 60
 Females more common than males by 3 to
1 ratio
 Prognosis directly related to tumor size
[less than 1.0 cm - good prognosis]
 Rarely associated with radiation exposure
 Spread to lymph nodes is uncommon
(~10%)
FOLLICULAR CANCER
Invasion into vascular structures
(veins and arteries) within the thyroid
gland is common.
Distant spread (to lungs or bones) is
uncommon, but more common than
with papillary cancer.
Overall cure rate high (near 95% for
small lesions in young patients),
decreases with advanced age.
FOLLICULAR THYROID CANCER
 Many cases of follicular thyroid cancer are
subclinical.
 Most common presentation of thyroid
cancer is an asymptomatic thyroid mass,
or a nodule, that can be felt in the neck.
 Some patients have persistent cough,
difficulty breathing, or difficulty
swallowing.
 Pain seldom is an early warning sign of
thyroid cancer.
FOLLICULAR THYROID CANCER
Other symptoms (rare):
 pain,
 stridor,
 vocal cord paralysis,
 hemoptysis,
 rapid enlargement.
These symptoms can be caused by less
serious problems.
FOLLICULAR THYROID CANCER
At diagnosis, 10-15% of patients
have distant metastases to bone
and lung and initially are
evaluated for pulmonary or
osteoarticular symptoms (eg,
pathologic fracture, spontaneous
fracture).
MANAGEMENT OF FOLLICULAR
THYROID CANCER
Follicular carcinoma should always be
treated with total thyreoidectomy.
A completion thyreoidectomy should
always be performed in patients who
have undergone a lobectomy for a
presumed benign tumor that proved to
be follicular carcinoma at definitive
histology.
MANAGEMENT OF FOLLICULAR
THYROID CANCER AFTER SURGERY
Perform postoperative scintiscan
of the neck after 4-6 weeks.

If thyroid tissue is present, a
dose of radioactive iodine is
administrated to destroy
residual tissue.
MANAGEMENT OF FOLLICULAR
THYROID CANCER AFTER SURGERY
Repeat scintiscan 6-12 months
after ablation and, thereafter,
every 2 years.
Radioactive iodine may ablate
the metastatic tissue in the lungs
and bone.
MANAGEMENT OF FOLLICULAR
THYROID CANCER AFTER SURGERY
Perform thyroid hormone
suppression in all patients with
total thyroidectomies and in all
patients who have had
radioactive ablation of any
remaining thyroid tissue.
MANAGEMENT OF FOLLICULAR
THYROID CANCER AFTER SURGERY
A patient who has had a
thyroidectomy without parathyroid
preservation will require vitamin D
and calcium for the rest of their life.
Evaluate thyroglobulin serum levels
every 6-12 months for at least 5
years.
FOLLICULAR ADENOMA
It is benign neoplasm.
No differentiation is possible between
adenoma and carcinoma by cytology
or in most cases even by frozen
section.
Capsular and vascular invasion are key
features that distinguish between
benign and malignant follicular
proliferation.
HÜRTHLE CELL CARCINOMA
WHO 1988: oxyphilic variant of
follicular carcinoma.
It may be also Hürthle cell
variant of papillary thyroid Ca.
Some authors classify it
separately as Hürthle cell
carcinomas.
HÜRTHLE CELL CARCINOMA
 Although preferentially classified
among follicular tumors, Hüthle cell
carcinomas are usually more
aggresive and metastasizing, and
they are less prone to take up
radioiodine and produce
thyroglobulin than welldifferentiated thyroid carcinomas.
ANAPLASTIC CANCER
Peak onset age 65 and older.
Very rare in young patients.
Males more common than females by
2 to 1 ratio.
Can occur many years after radiation
exposure.
Typically presents as rapidly growing
neck mass.
ANAPLASTIC CANCER
Spread to lymph nodes of the neck
present in more than 90% of cases.
Distant spread (to lungs or bones) is
very common even when first
diagnosed.
Overall 5-year survival rate is
reportedly less than 10%, and most
patients do not live longer than a few
months after diagnosis.
ANAPLASTIC CANCER
SYMPTOMS
A rapidly growing neck mass
Dysphagia
Cough
Neck pain
Dyspnea
Patients with metastases also may note
bone pain, weakness, and cough
Neurologic deficits may be observed with
brain metastases.
ANAPLASTIC CANCER
SURGICAL CARE
Perform surgery in conjunction
with radiation and
chemotherapy.
Use surgery to obtain a definitive
diagnosis when fine needle
aspiration is unsuccessful.
ANAPLASTIC CANCER
Despite the typically large size
of these tumors, extent of
resection is limited when
diagnosis is made.
ANAPLASTIC CANCER
Rather than performing complete
thyroidectomy, resect as much
thyroid tissue as possible without
attempting resection of all adjacent
structures because of the high
incidence of postoperative morbidity
(eg, vocal cord paralysis, esophageal
fistula).
ANAPLASTIC CANCER
FURTHER INPATIENT CARE
Radiotherapy:
Despite the fact that ATC is
largely radioresistant, use
external beam radiotherapy for
local control.
ANAPLASTIC CANCER
Chemotherapy:
Currently, no available chemotherapeutic
agent or combination of chemotherapeutic
agents shows sufficient antineoplastic
activity to prevent death;
yet in rare instances, chemotherapy may
prolong life by a few weeks or perhaps
months.
Doxorubicin and cisplatin are the two most
common agents used.
MEDULLARY THYROID CANCER
A distinct thyroid carcinoma that
originates in the parafollicular C
cells of the thyroid gland.
These C cells produce calcitonin.
Females more common than
males
(except for inherited cancers).
MEDULLARY THYROID CANCER
Regional metastases (spread to
neck lymph nodes) occurs early
in the course of the disease.
Spread to distant organs
(metastasis) occurs late and can
be to the liver, bone, brain, and
adrenal medulla.
MEDULLARY THYROID CANCER
Not associated with radiation
exposure.
Usually originates in the upper
central lobe of the thyroid.
MEDULLARY THYROID CANCER
Poor prognostic factors include
age >50, male, distant spread
(metastases), and MEN II-B.
Residual disease (following
surgery) or recurrence can be
detected by measuring
calcitonin.
MEDULLARY THYROID CANCER
FOUR CLINICAL SETTINGS
 SPORADIC
Accounts for 80% of all cases of medullary
thyroid cancer
 MEN II-A (SIPPLE SYNDROME)
 bilateral medullary carcinoma or C
cell hyperplasia,
 pheochromocytoma
 hyperparathyroidism
MEDULLARY THYROID CANCER
FOUR CLINICAL SETTINGS
 MEN II-B
 medullary carcinoma
 pheochromocytoma
 an unusual appearance which is
characterized by mucosal
ganglioneuromas (tumors in the mouth)
and a Marfanoid habitus.
 hyperparathyroidism (uncommon)
 INHERITED MEDULLARY CARCINOMA
WITHOUT ASSOCIATED ENDOCRINOPATHIES.
Endocrine diseases occuring together
in different endocrine glands are due
to multiple, mostly hereditary benign
and malignant neoplasms or
hyperplasia with excessive function
(MEN=MEA),
or develop in response to an
autoimmune reaction affecting
different endocrine and perhaps other
glands
(autoimmune polyglandular syndromes
=APS)
AUTOIMMUNE POLYGLANDULAR
SYNDROMES
TYPE 1 = Blizzard’s
syndrome
TYPE 2 = Schmidt’s
syndrome
Major components:
Major components:
 Chronic
mucocutaneous
candidiasis
 Autoimmune thyroid
disease
 Type 1 diabetes melltus
 Hypoparathyroidism
 Addison’s disease
 Addison’s disease
 Premature ovarian failure
+ other
endocrinopathies and
features
+ other endocrinopathies
and features
MEDULLARY THYROID CANCER
SYMPTOMS
a lump at the base of the neck,
especially during swallowing;
hoarseness, dysphagia, and
respiratory difficulty;
MEDULLARY THYROID CANCER
SYMPTOMS
various paraneoplastic syndromes,
including Cushing or carcinoid
syndrome (uncommon).
Diarrhea secondary to high plasma
calcitonin levels.
Distant metastases.
MEDULLARY THYROID CANCER
WORKUP
Serum calcitonin levels.
Pentagastrin-stimulated calcitonin
levels.
DNA testing for RET (it may replace the
diagnostic method mentioned above).
24-hour urinalysis for catecholamine
metabolites.
MEDULLARY THYROID CANCER
WORKUP
Screening for the development of
familial MCT in family members of
patients with history of MCT or MEN 2A
or 2B.
Screen all family members for missense
mutation in RET in leukocytes.
MEDULLARY THYROID CANCER
WORKUP
A cervical ultrasound
(to detect LN metastases).
CT scan, MRI, and bone scans.
Fine needle aspiration.
MEDULLARY THYROID CANCER
MANAGEMENT
 All patients should receive total
thyroidectomy, a complete central neck
dissection (removal of all lymph nodes and
fatty tissues in the central area of the neck),
and removal of all lymph nodes and
surrounding fatty tissues within the side of
the neck which harbored the tumor.
 Radioactive iodine therapy is not useful.
MEDULLARY THYROID CANCER
MANAGEMENT
Long-Term Follow
A yearly chest x-ray as well as
calcitonin levels.