This document provides an overview of thyroid tumors, including their epidemiology, classification, clinical features, investigations, and treatment. It discusses the main types of benign and malignant thyroid tumors such as follicular adenoma, papillary carcinoma, follicular carcinoma, medullary carcinoma, and anaplastic carcinoma. Papillary carcinoma is the most common thyroid malignancy. Follicular carcinoma and medullary carcinoma can occasionally be familial. Anaplastic carcinoma is very aggressive and usually has a poor prognosis.

1. THYROID TUMORS

2. OUTLINE
• Introduction
• Epidemiology
• Aetiology
• Classification
• Clinical features
• Investigations
• Treatment
• Prognosis

3. Epidemiology
• US: 40 per 1,000,000 per year
• <1% of all malignancies
• 6 deaths per million deaths p.a

4. Aetiology
• Irradiation of the thyroid.atomic bomb expo
• Heredity: RET oncogene (xsome 10) plays
a significant role in the devt of papillary
thyroid cancer. More common in childhood
thyroid cancer. Others are C-myc, C-fos,
C-ras, C-erb B2/neu. Mutated ras gene,
implicated in follicular tumors. Point
mutations in p53 gene (a tumor suppressor
gene), common in most anaplastic thyroid
cancers.
• Sustained TSH stimulation
• Nearness to volcanoes

5. Classification
• Benign
Follicular adenoma
• Malignant
Primary
• Differentiated tumors of follicular origin
- Papillary ca
- Follicular ca
Differentiated of parafollicular origin
- Medullary
• Undifferentiated / Anaplastic
Secondary
• Metastatic

6. FOLLICULAR ADENOMA
• Typically, discrete, solitary masses derived
from follicular epithelium
• Clinically, it may be difficult to distinguish
from follicular hyperplasia or carcinoma.
• They are usually not premalignant xcept in
rare cases.
• Usually non-functional tho some may
produce hormones independent of TSH
stimulation I.e toxic adenomas.

7. Pathology
• Mutation in TSH receptor leading to clonal
expansion of follicular epith
• Macro: A solitary, spherical encapsulated
lesion well demarcated from surrounding
thyroid parenchyma.
• Micro: Uniform-appearing follicles
containing colloid
The integrity of the capsule is important in
distinguishing it from a follicular Ca.

8. Features
• A unilateral painless mass
• Large masses = pressure symptoms.
• Toxic adenomas = symp of hyperthyroidism
Appear as cold nodules on radionuclide
scanning
• Ultrasonography
• Incisonal biopsy
Thyroidectomy to rule out malignancy.
PROGNOSIS is excellent, do not recur or
metastasize.

9. Rare benign tumors
• Dermoid cyst
• Lipoma
• Hemangioma

10. PAPILLARY CARCINOMA
• Most common thyroid malignancy, approx
80% in Europe but abt 20% in Nigeria
• The predominant thyroid ca in children,
75% and people previously exposed to
radiation in the neck (85 – 90%).
• Commoner in women, 2:1 male to female
• Mean age at presentation is 20 to 40yrs.

11. Pathology
• Usually hard and whitish and remain flat on
sectioning with a blade, rather than bulging.
• Hisologically, they exhibit papillary
projections or mixed pattern.
• Has chacteristic cellular features- pale
abundant cyto, crowded nuclei (Orphan
Annie cells).
• Psammoma bodies may be present
• Higher propensity for lymphatic spread and
direct spread to contiguous structures.
Haematogenous metastases is a late feature.

12. Clinical features
• Most patients are euthyroid.
• A slow-growing painless mass in the neck.
• Local invasion – dysphagia, dyspnea,
hoarseness.
• Enlarged ipsilateral cervical glands, infact
may be more apparent than the pry lesion –
the lateral aberrant thyroid.
• Distant metastases in 1-15%

13. Diagnosis
• FNAC
• Radioiodine thyroid scans: Failure to take
up radioiodine is xteristic (cold masses)
• Thyroid antibody test
• CT Sscan
• MRI

14. TNM Staging• TUMOR
TX Primary cannot be assessed
T0 No evidence of primary
T1 Limited to thyroid < 1cm
T2 Limited to thyroid, >1cm but <4cm
T3 Limited to thyroid >4cm
T4 Extension to capsule, any size
NODES
NX Cannot be assessed
NO No regional node metastases
N1 Regional node metastases
METASTASES
MX Cannot be assessed
M0 No metastases
M1 Distant metastases

15. Management
• Unilateral lobectomy and isthmectomy
• Total or near-total thyroidectomy for
bilateral dx or high risk patient
• Thyroxine 0.1-0.2mg daily to suppress
endogenous TSH production
• Radioiodine to tx metastases if detected by
scanning
• Thyroglobulin measurement to detect
metastases post-op

16. Prognosis
AGES Scale- Age, Grade, Extent of disease,
Size of tumor.
• Low risk = young, well diff tumor, no metastases,
small pry lesion.
• High risk =older, poorly diffd, local invasion,
distant metastases, large pry lesion
MACIS Scale- distant Metastasis, Age at
presentation, Completeness of original surgical
resection, extrathyroidal Invasion, Size of lesion.
AMES- Age, Metastases, Extent, Size
DNA Ploidy

17. FOLLICULAR CARCINOMA
• Accounts for about 20% of thyroid
malignancies in Europe but abt 60% in
Nigeria.
• Iodine-deficiency – hyperplasia -- neoplasia
• Female to male ratio is 3:1
• Age at presentation is 40 - 50yrs.
• Hurthle cell tumors are a variant of FC in
which oxyphil cells predominate. Assd with
poorer prognosis.

18. Pathology
• Usually solitary and encapsulated in 90%.
• Haematogenous spread occurs more
commonly. Lymphatic spread is a late fx,
(<10%).
• Histologically, numerous follicles are seen
which may be devoid of colloid.

19. Clinical features
• A solitary thyroid nodule with hx of rapid
increase in size or hx of long standing
goitre.
• Usu painless but can become painful if
haemorrhage into the nodule occurs.
• Cervical lymphadenopathy is uncommon.
• Distant metastases.
• Rarely, features of thyrotoxicosis (<1%).

20. Management
• Definite pre-operative diagnosis is difficult
bcos FNAC is unable to differentiate a
benign follicular adenoma from a
carcinoma.
• Px diagnosed by FNAC as having a
follicular lesion should undergo thyroid
lobectomy. Frozen section examination is
done and diagnosed carcinomas shld have
total thyroidectomy + radioactive iodine +
Thyroxine

21. MEDULLARY CARCINOMA
• Accounts for about 5% of thyroid carcinomas.
• Arise from parafollicular or C cells derived from
neural crest, found majorly in the lateral parts of
superior poles.
• C cells secrete calcitonin wc has opposing action
to PTH and lowers serum Ca levels. Also secretes
serotonin, PGs, histamine, ACTH, somatostatin,
bombesin, VIP.
• C cell hyperplasia is a premalignant precursor.

22. Associations
May be familial (30%) or sporadic(70%).
Familial dx occurs as part of other
endocrinopathies.
• NON-MEN MTC
• MEN IIA or Sipple’s syndrome - MTC +
Hyperparathyroidism + Phaechromocytoma
• MEN IIB – MTC + Phaechromocytoma +
Ganglioneuromatosis + Marfan’s syndrome

23. Pathology
• Located in middle to upper thyroid poles
• Unilateral in about 75% of sporadic cases
but with familial cases, 90% are bilateral.
• Has chacteristic amyloid stroma
• Immunohistochemistry for calcitonin is a
diagnostic tumor marker. Also stain for
carcinoembryonic antigen (CEA),
histaminase and calcitonin gene-related
peptide..
• lymphatic spread occur initially before
distant haematogenous occurs

24. Clinical fx
• A painful neck mass
• Palpable cervical lymphadenopathy in 15-20%
• Local invasion:
• Diarrhea (VIP)
• Cushing,s syndrome from ectopic ACTH
production
• Kidney stones
• Hypertension

25. Management
• Genetic screening for familial cases +
estimation of serum calcitonin. Prophylactic
thyroidectomy are offered.
• Treatment = Total thyroidectomy and
resection of involved lymph nodes.
• In all cases b4 surgery,
phaeochromocytoma must be excluded by
measurement of urinary catecholamines.

26. ANAPLASTIC CARCINOMA
• One of the most aggressive malignancies
with few patients surviving 6mths beyond
diagnosis.
• Incidence is abt 1% in US, but 5% in
Nigeria. Endemic goiter is a precursor.
• Common in elderly women, 7th
– 8th
decade.

27. • PATHOLOGY:
• Growth is extremely rapid, local infiltration
an early feature. Spreads by lymphatics and
blood stream.
• Microscopically, sheets of undifferentiated
small or giant cells are seen.

28. CLINICAL FEATURES
 elderly women with hx of lump in the neck which
suddenly enlarged rapidly and became painful.
 Associated dysphonia, dysphagia and dyspnea.
 Tumor is hard and may be fixed to surrounding
structures, may be ulcerated.
 Palpable lymph nodes usually.
 Evidence of metastases.

29. Mgt
• Diagnosis is by FNAC- reveals giant and
multinucleated cells. Incisional biopsy may
be used to confirm the diagnosis.
• TREATMENT
Radiotherapy
Debulking thyroidectomy
Chemotherapy wt Doxorubicin
PROGNOSIS: Poor. Mortality =100%.
Survival rarely exceeds 6months even wt
treatment

30. LYMPHOMAS
• Approx 1% of thyroid maligs.
• Most are non-Hodgkin’s B-cell type.
• Usually develop in patients with chronic
lymphocytic thyroiditis (Hashimoto’s).
• Px presents with features of anaplastic tumors,
altho the rapidly enlarging mass is painless.
• Diagnosis is suggested by FNAC, needle or open
biopsy is necessary for definitive diag. Lymph
nodde biopsy helps clarify.

31. • Response to chemo is good. CHOP-
Cyclophosphamide, doxorubicin,
vincristine and prednisolone.
• Combined radiotherapy and chemo is
recommended. Thyroidectomy is used to
alleviate tracheal compression.
• Prognosis is good if cervical nodes are not
involved.

32. METASTATIC CA
• The thyroid gland is a rare site for
metastases.
• Most common metastatic tumor is a
hypernephroma. Others include breast,
lung, melanoma

33. Rare neoplasms
• Fibrosarcoma
• Teratoma
• Sq. cell carcinoma
• mucoepidermoid