An introduction to thyroid neoplasms
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This document provides an introduction to thyroid neoplasms (tumors). It discusses the main types of benign and malignant thyroid tumors. For benign tumors, it describes follicular adenomas, which are benign, encapsulated tumors showing follicular differentiation. For malignant tumors, it outlines the primary tumor types: epithelial tumors like papillary and follicular carcinoma, and non-follicular tumors like medullary carcinoma. It then provides more detail on the most common malignant tumors. Papillary carcinoma accounts for 60% of thyroid cancers and often presents as multiple tumors. Follicular carcinoma spreads via angioinvasion and hematogenously. Anaplastic carcinoma is highly lethal and aggressive. Medullary carcinoma can
An introduction to thyroid neoplasms
- 1. An Introduction to thyroid neoplasms Hosam Mohamad Hamza, MD Lecturer of General & laparo-endoscopic surgery Minia Medicine Minia Egypt 2016
- 2. 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
- 3. 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)
- 5. 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–USthyroidInvestigations: + biopsyhemithyroidectomy:Treatment
- 7. 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
- 8. 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 malignancyprimaryRisk Factors of (POINTERS to thyroid malignancy)
- 9. A- 5 suggestive manifestations. B- 5 sure manifestations. C- Occasional presentations. Clinical manifestations of thyroid carcinomas
- 10. A- laboratory: - thyroid function tests. - tumour markers. B- radiological: - US - CT C- others: - thyroid scan - biopsy Investigations
- 11. 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
- 12. • 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
- 13. Microcarcinomas (occult carcinomas): • Definition - papillary carcinomas < 1.0 cm • Usually clinically silent. • Most are found incidentally at autopsy. Papillary thyroid carcinoma, continued
- 14. Microscopic Pathology: • Closely packed papillae with little colloid. • Psammoma bodies – laminated calcified bodies. • Nuclei are oval or elongated and pale. Papillary thyroid carcinoma, continued
- 15. Papillary thyroid carcinoma, continued
- 17. Psammoma Bodies
- 18. Optically clear nuclei (Orphan Annei-eye nuclei)
- 19. • 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
- 21. Microscopic Pathology: • Evidence of vascular and capsular invasion. • FNAC cannot accurately distinquish between benign and malignant lesions Follicular thyroid carcinoma, continued
- 23. Capsular invasion Vascular invasion Nuclear features Vascular invasion
- 24. • 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
- 25. Microscopic Pathology: • Clusters or sheets of very poorly differentiated cells. • Numerous mitoses. • extrathyroidal invasion. Anaplastic thyroid carcinoma, continued
- 27. • 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
- 28. MEN IIA: MTC. Phaeochromocytoma. Parathyroid adenoma or hyperplasia MEN IIB: MTC Phaeochromocytoma Mucosal ganglioneuromas Marfanoid habitus Hirscheprung’s disease Medullary thyroid carcinoma, continued
- 29. Microscopic Pathology: 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
- 30. 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) Medullary thyroid carcinoma, continued
- 31. 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.
- 32. Large Cell Lymphoma of the Thyroid
- 33. 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
- 34. I131 Total Body Scan
- 35. TreaTmenT of thyroid carcinomas 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.
- 36. TreaTmenT of thyroid carcinomas 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