CLINICALLY DISCRETE SWELLINGS

DISCRETE THYROID SWELLING

DISCRETE THYROID SWELLINGS Isolated or Solitary (70%): Discrete

swelling in an otherwise impalpable gland

Dominant (30%): similar swelling in a gland with clinical evidence of generalized abnormality in the form of a palpable contralateral lobe or generalized mild nodularity

IMPORTANCE

Increased risk of neoplasia compared with other thyroid swellings

Solitary15%

malignant

30-40% follicular adenoma

Dominant

Incidence of malignancy or follicular adenoma

half of that of solitary swelling

INVESTIGATIONS

Thyroid function tests Autoantibody titres Isotope scan Ultrasonography FNAC Radiology Other scans- CT and MRI Laryngoscopy Core biopsy

1. THYROID FUNCTION Serum TSH, T3 and T4 Hyperthyroidism

Toxic adenoma Toxic Multi Nodular Goitre

Indication for isotope scanning to localize the area(s) of

hyperfunction

Combination of toxicity and nodularity

2. AUTOANTIBODY TITRE

To determine whether the swelling is a manifestation of chronic lymphocytic thyroiditis

Presence of circulating antibodies increases the risk of thyroid failure after Lobectomy

3. ISOTOPE SCAN

Swellings

HOT: overactiv

eWARM: activeCOLD:

underactive

ISOTOPE SCAN… Hot nodule: takes up isotope while

surrounding thyroid tissue does not. Here the surrounding thyroid tissue is inactive because the nodule is producing such high levels of thyroid hormone that TSH secretion is suppressed.

Warm nodule: takes up isotope and so does the normal thyroid tissue around it

Cold nodule: does not take up isotope. 80% of discrete swellings are cold.

THYROID ISOTOPE SCAN

4. ULTRASONOGRAPHY Non invasive To determine physical characteristics

of swellingFeatures of thyroid

neoplasia• Microcalcification• Increased vascularity• Macroscopic capsular

breech• Nodal involvement

Diagnostic of malignancy

5. FNAC“Investigation of choice”

Excellent patient compliance Simple and quick Readily repeated

FNAC can diagnose

Colloid nodules Thyroiditis Papillary carcinoma, Medullary carcinoma and Anaplastic carcinoma

Lymphoma

DISADVANTAGES OF FNAC

Cannot distinguish between a benign follicular adenoma and follicular carcinoma. Because this distinction is dependent not on cytology but on histological criteria, which include capsular and vascular invasion

False negative High rate of unsatisfactory aspirates

(ultrasound guided aspiration can achieve more accurate sampling)

6. RADIOLOGY

Chest and thoracic inlet radiographs to confirm tracheal deviation, compression or retrosternal extension

7. OTHER SCANS

CT and MRI Give excellent anatomical detail No role in first line of investigation Useful in assessing retrosternal and

recurrent swellings PET scan

Useful in localizing disease which does not take up radioiodine

8. LARYNGOSCOPY

To determine the mobility of the vocal cords

Usually for medicolegal reasons rather than clinical reasons

Presence of unilateral cord palsy + thyroid swelling suggestive of malignancy

9. CORE BIOPSY

For histological assessment High diagnostic accuracy but

requires local anaesthesia, and may be associated with complications such as Pain Bleeding Tracheal damage Recurrent laryngeal nerve damage

TREATMENT-DISCRETE SWELLINGS

THYROIDECTOMY Indications:

Risk of neoplasia (including follicular adenoma)

Malignant swellings Relative indications:

Age (in a teenager provisinally diagnosed as carcinoma, risk increases >50 years)

Sex (much more likely to be malignant in male)

Size of swelling

THANK YOU!!!