الفهرس 
PATHOLOGY OF SOLITARY THYROID NODULEOnly 14 pages are availabe for public view
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Abstract
Solitary thyroid nodule is a common problem in medical practice, its incidence in the general population has been estimated to be 4-7%.
The vast majority of thyroid nodules are benign; the aim of management and investigation is to detect those malignant lesions to select them for surgery.
Management strategy involves the integration of information from a variety of possible sources including history, clinical examination, biochemical assessment and a spectrum of additional investigation.
Laboratory investigations including: T3, T4, TSH, serum calcitonin and serum thyroglobulin. It is pointed out that laboratory tests give no great help in the evaluation of solitary thyroid nodules.
Chest radiography and thoracic inlet view are not routinely indicated for the patient with solitary thyroid nodule but should be requested in the presence of obstructive symptoms, tracheal deviation or suspected retrosternal extension.
Ultrasonography of the thyroid gland is used in differentiating the true solitary thyroid nodule from those with multinodular gland. Also it classifies the nodules into solid, cystic, or mixed. However it admits a little help in determining the pathological types of the nodule.
Radioisotope scanning of the thyroid after a tracer dose of an isotope will show the nodule hot, warm, or cold. The cold nodule is considered suspicious for carcinoma, these lesions have a 5-10% chance of malignancy, however the most thyroid nodules are cold, including cysts, colloid nodules, benign follicular lesions, hyperplastic nodules, and nodules of Hashimoto’s.
Computed tomography (CT) is occasionally indicated in the evaluation of thyroid disease. The anatomical structures of the neck and mediastinum that may be involved by thyroid cancer are best evaluated by contrast CT scans.
Positron Emission Tomography scanning (PET) with FDG appears promising in the workup of patients with thyroid nodules as it can differentiate malignant from benign nodules depending on the dose uptake ratio.
At present, FNAC has replaced other methods, and became the first and the routine method which must be used in diagnosis of solitary thyroid nodule. It has a great accuracy in identification of different pathologic types and in differentiating benign from malignant lesions, except in the follicular tumor group. The only value of the other methods of diagnosis became in supportive role.
The method of solitary thyroid nodule management depends chiefly on the scheme used in the diagnosis and treatment.
As for the autonomous toxic nodule, the treatment is either by radioactive iodine or surgical resection.
For the cystic nodules aspiration is both diagnostic and treatment, with post aspiration observation. Thyroid lobectomy is recommended in patient whom a cyst has recurred after three aspirations.
The colloid nodules either observed or suppressed by thyroxin, also surgery is recommended if the nodule grows; only for exclusion of malignancy.
In thyroiditis, the medical treatment takes the upper hand with fewer roles for surgery, which is mainly in the form of tracheal decompression or biopsy taking for assurance of diagnosis.
In follicular neoplasm, subtotal thyroidectomy with histological examination of the nodule is performed. If adenoma is diagnosed, only thyroxin therapy for suppression is used. But in cases of carcinoma completion thyroidectomy with adjuvant treatment in the form of radioactive iodine and suppressive therapy.
In other malignant lesions, total or near total thyroidectomy is performed with adjuvant treatment according to the type of malignancy, except in lymphoma whose response to chemotherapy and external radiation give good results.
As regard the recent trends in the management of solitary thyroid nodule, most patients until recently have been referred for operative treatment, although surgery is still the main method of treatment in such patients, the number of patients with solitary thyroid nodules treated surgically is less than in the past.
Percutanous ethanol injection under sonographic guided is a relatively safe, low cost, outpatient method of treatment that has been applied successfully as an alternative to surgery for the management of benign and malignant lesions of various tissues and organs. Among endocrine diseases, thyroid nodules; both cystic and solid, have been treated effectively using this technique.
U.S. guided interstitial laser photocoagulation could become a useful non surgical alternative in the treatment of benign solitary solid cold thyroid nodule in patients who can’t or will not undergo surgery.
Although conventional open thyroidectomy can be performed with few complications, this approach leaves a visible scar on the anterior surface of the neck in a cosmetically unfavorable location.The endoscopic approach provides a superior cosmetic result when compared to conventional thyroidectomy and results in a quicker return to normal activity. Also provides fantastic magnification of thyroid anatomy, including the recurrent laryngeal nerve, superior laryngeal nerve, and the parathyroid glands.