An introduction to thyroid neoplasms

An Introduction to

thyroid neoplasms

Hosam Mohamad Hamza, MD

Lecturer of General & laparo-endoscopic surgery

Minia Medicine

Minia

Egypt

2016

teratoma

lipoma

adenoma

• A neoplasm or a tumour is a condition where automonus

irreversible purposeless proliferation of cells leads to

formation of an abnormal mass or growth.

• Thyroid tumours are either

Primary

tumours metastatic

tumours

Benign

tumours Malignant

tumours

BENIGN TUMOURS OF THE THYROID

Follicular Adenoma

• Benign, encapsulated tumour showing

evidence of follicular differentiation

• Predominantly in young to middle women

• Presents as solitary thyroid nodule (painless

nodular mass, cold on isotopic scan)

Types of follicular adenomas:

1- Microfollicular adenoma (very small follicles)

2- Normofollicular adenoma (normal sized follicles)

3- Macrofollicular adenoma (large follicles distended with colloid)

4- Hurthle cell adenoma (follicles lined by large polyhedral cells =

Hurthle cells)

Thyroid noduleSolitary :presentationClinical

thyroid scan –biopsy –US thyroid Investigations:

+ biopsy hemithyroidectomy: Treatment

ADENOMA

NORMAL

MALIGNANT TUMOURS OF THE THYROID

Primary tumours Secondary tumours

From:

* Nearby cancer

* Renal Carcinoma

* Breast Carcinoma

* Colonic Cancer

* Melanoma

1- Epithelial:

a- follicular

b- non-follicular (C-cells)

2- Mesenchymal = sarcoma

3- Others:

a- lymphoma

b- squamous cell carcin

c- mucoepidermoid arcin

1- Prior neck irradiation early in life (the most

important single factor):

• External:

- Treatment for malignancies

- Nuclear weapons/accidents

• Internal:

treatment with I131

2- Prior thyroid lesions:

• Thyroid cancer

• STN (esp. males in age extremes)

• Simple Nodular Goitre (uncertian)

• Hashimoto’s thyroiditis (uncertain)

3- Genetic. e,g. Cowden’s syndrome

thyroid malignancy primaryRisk Factors of (POINTERS to thyroid malignancy)

A-

5 suggestive manifestations.

B-

5 sure manifestations.

C-

Occasional presentations.

Clinical manifestations of thyroid carcinomas

A- laboratory:

- thyroid function tests.

- tumour markers.

B- radiological:

- US

- CT

C- others:

- thyroid scan

- biopsy

Investigations

1- Carcinoma of follicular origin:

a. Well-differentiated thyroid carcinoma (WDTC):

- papillary carcinoma (60%)

- follicular carcinoma.

- mixed type

b. Non-differentiated thyroid carcinoma:

anaplastic carcinoma

2- Carcinoma of non-follicular origin:

medullary carcinoma

Types of primary thyroid carcinomas

• 60%-80% of all thyroid cancers.

• Multiple histologic subtypes.

• Children and young adults.

• Females > Males.

• Lymphatic > haematogenous spread

(46%-90% of patients have lymph node involvement)

• Often multicenteric.

• Microcarcinomas may occur

Papillary thyroid carcinoma

Microcarcinomas (occult carcinomas):

• Definition - papillary carcinomas < 1.0 cm

• Usually clinically silent.

• Most are found incidentally at autopsy.

Papillary thyroid carcinoma, continued

Microscopic Pathology:

• Closely packed papillae with little colloid.

• Psammoma bodies – laminated calcified bodies.

• Nuclei are oval or elongated and pale.



Psammoma Bodies

Optically clear nuclei (Orphan Annei-eye nuclei)

• 20% of all thyroid malignancies.

• Women > Men.

• More in middle age.

• Metastasis by angioinvasion and haematogenous

spread.

• 15% present with distant metastases (bone and

lung).

Follicular thyroid carcinoma

20

Follicular thyroid carcinoma


• Evidence of vascular and capsular invasion.

• FNAC cannot accurately distinquish between

benign and malignant lesions

Follicular thyroid carcinoma, continued

Capsular invasion

Capsular invasion

Capsular invasion Vascular invasion

Nuclear features Vascular invasion

• Highly lethal form of thyroid cancer (median

survival < 8 months )

• 1%-10% of all thyroid cancers.

• Affects the elderly (30% of thyroid cancers in

patients >70 years).

• Direct spread.

Anaplstic thyroid carcinoma


• Clusters or sheets of very poorly differentiated

cells.

• Numerous mitoses.

• extrathyroidal invasion.

Anaplastic thyroid carcinoma, continued

• Arises from the para-follicular C-cells of the

thyroid gland which secrete calcitonin (Ca

metabolism).

• Diarrhea may be the presenting complain.

• Develops either as sporadic or familial types:

1- Sporadic MTC:

- no family history.

- middle and old age.

- Slightly more aggressive than Familial type.

2- Familial MTC: - young age.

- autosomal dominant transmission.

- Multiple Endocrine Neoplasia II a and b

Medullary thyroid carcinoma

MEN IIA:

MTC.

Phaeochromocytoma.

Parathyroid adenoma or hyperplasia

MEN IIB:

MTC

Phaeochromocytoma

Mucosal ganglioneuromas

Marfanoid habitus

Hirscheprung’s disease

Medullary thyroid carcinoma, continued



- Same for sporadic & familial

- Solid, lobular or insular growth

patterns

- Tumour cells round, polygonal or

spindle-shaped

- Amyloid deposits in many

Cases

- Haematogenous and lymphatic

spread

Diagnosis

Labs:

1. serum calcitonin levels

2. 24 hour urinary catecholamines

Rad:

Others:

1. Fine needle aspiration

2. Genetic testing of all first

degree relatives (RET proto

oncogene)


Primary Thyroid Lymphoma

- A rare type (5% of thyroid cancers)

- Develops in the setting of pre-existing

lymphocytic thyroiditis.

- Often diagnosed because of airway

obstruction symptoms

- Radiosensitive.

- Good prognosis.

Large Cell Lymphoma of the Thyroid

TreaTmenT of thyroid carcinomas

* Surgery is the main line of treatment.

* In WDTC:

1- total thyroidectomy.

2- If any cervical nodes are clinically palpable or

identified by MR or CT imaging as being suspicious,

neck dissection should be done (prophylactic neck

dissections are not done)

3- Hormone replacement therapy (T3)

4- Radioactive iodine (RAI):

= thyroid scan is done 30 days postoperatively (to allow

metastases – if present – to flourish.

= if secondaries are detected → ablative dose of RAI → 2

weeks later scan. Then every 6 months for 2 years. Then

every 12 months for 5 years

I131 Total Body Scan


continued

* In Anaplastic carcinoma:

- Most cases have extensive extrathyroidal involvement

at the time of diagnosis = surgery is limited to biopsy &

tracheostomy.

- Current standard of care is maximum surgical debulking

if possible then adjuvant radiotherapy and chemotherapy.


continued

* In Sporadic medullary carcinoma:

- Total thyroidectomy.

- Central lymph node dissection

In Familial medullary carcinoma:

- patient: ??

= remove pheochromocytoma before thyroid surgery

- relatives ??

= total thyroidectomy and central lymph node dissection

= SURGERY IS ONLY EFFECTIVE THERAPY

Papillary Best prognosis

Follicular

Medullary

Anaplastic Worst prognosis

Thank You

[email protected]

mailto:[email protected]




Education

An introduction to thyroid neoplasms