Benign
- Papillary adenoma
- Follicular adenoma
Malignant
Primary
- Papillary carcinoma
- Follicular carcinoma
- Anaplastic carcinoma
- Medullary carcinoma
- Lymphoma
Secondary
- From direct or blood-borne
Treatment
- Prophylactic
- Avoid predisposing factors such as neck irradiation
- Treatment of the Tumor
A. Differentiated Carcinoma (Follicular & Papillary)
- Surgical: Total thyroidectomy + block dissection of neck LNs + L-thyroxin replacement (preserve parathyroid).
- Radioactive iodine: To destroy any remnant + ablate any metastasis.
B. Anaplastic Carcinoma
- The majority of cases are irresectable at the time of presentation, so treatment is palliative:
- Tracheostomy, isthmus resection, or surgical debulking.
- Radiotherapy and chemotherapy.
- Rare cases are operable: total thyroidectomy followed by radio & chemotherapy.
Post Operative Follow-Up
- Every 3 months by thyroid scanning, clinical examination, and tumor marker.
Medullary Carcinoma
Investigations
- As before +
- For screening: in familial type Calcitonin if high in patient (used as a tumor marker).
Treatment
- Thyroid: Total thyroidectomy & block dissection of LN.
- Parathyroid:
- If sporadic: preserve all parathyroid glands
- If familial: preserve only 1/2 parathyroid gland
| Feature | Papillary Carcinoma | Follicular Carcinoma | Anaplastic Carcinoma |
|---|---|---|---|
| Incidence | 70% of thyroid neoplasm | 17% of thyroid neoplasm | 13% of thyroid neoplasm |
| Age | Children & young adult | Middle age | Elderly |
| Sex (F:M) | 3.5:1 | 2:1 | 1:1.3 |
| Predisposing factor: | - External irradiation of neck in children - Hemangiomas, T.B lymphadenitis. - Papillary adenoma - Genetic factors | - SNG. - Follicular adenoma. | Usually De Novo |
| Pathology: Macroscopic | Ill-defined mass infiltrating the surrounding. -Grey in color -Multicentric (80%) due to intrathyroid lymphatic spread. | Ill-defined mass infiltrating the surrounding. -Brown -Unicenteric | Ill-defined mass infiltrating the surrounding. -Grey -Unicenteric |
| Microscopic | Loss of polarity & signs of mitosis -Malignant papillae with vascular C.T. core covered by malignant cells. -Laminated calcified bodies (psammoma body) | Loss of polarity & signs of mitosis -Thyroid follicle with variable degrees of differentiation -Capsular &vascular invasion | Loss of polarity & signs of mitosis -Cluster of spindle cells(small or large) -Separated by little fibrous tissue. |
| Spread: | Mainly lymphatic to deep cervical L.N | Mainly blood to skull usually solitary, painful, pulsating, osteolytic (DD. abscess) | Mainly direct & can infiltrate carotid artery which may rupture. |
| TSH: | Dependent | less dependent | NOT dependent |
| C/P: A-Typical presentation | Symptoms: -Rapid growing swelling in front of the neck. -Painless, late painful -Pressure manifestations -Metastatic manifestation. Sign: -Thyroid swelling: early mobile, late hard fixed -Neck LNs: may be enlarged and hard -kocher sign: trachea is fixed to gland -berry sign: absent carotid pulse due to infiltration of carotid sheath. | Same as Papillary | Same as Papillary |
| B-Occasional Presentation | -Enlarged cervical LNs while thyroid carcinoma is not palpable. | -Solitary skull metastasis | Same as Follicular |
| Investigation: | 1-For diagnosis :U/S,FNABC 2-For staging: CT scan, CXR, Bone scan, abdominal U/S 3-Preoperative preparation:CBC, FBS,LFTs, KFTs,ECG 4-For follow up:Tumors markers | Same as Papillary | Same as Papillary |
| Prognosis: | good | Bad | Very Bad |
| 10 year survival: | 90% | Encapsulated 97% Invasive 70% | Die within 1-2 years |