Thyroid cancer
Anju Sahdev, Sarah J. Vinnicombe in Husband & Reznek's Imaging in Oncology, 2020
Total thyroidectomy is still undertaken for most papillary carcinomas (and their variants) and follicular and Hürthle cell carcinomas that are larger than 1 cm, but there is a trend towards partial thyroidectomy for low grade and borderline tumours. Lymph node dissection is undertaken if there is nodal involvement. Postoperative radioactive iodine therapy is usually given, and the patient rescanned with 123I at 3–6 months to confirm complete ablation and the absence of metastatic disease. Thyroid hormone is administered (often after radioiodine treatment is completed) to replace hormone and inhibit TSH production. Thyroglobulin as a tumour marker is used in the follow-up of patients after surgery but is only accurate as a marker when there is complete absence of thyroid tissue (13).
Endocrine tumours
Peter Hoskin, Peter Ostler in Clinical Oncology, 2020
Patients treated for differentiated thyroid cancer require life-long follow-up. This will involve regular thyroglobulin measurements. In the early post-treatment period whole body iodine uptake scans are performed. Thyroid hormone replacement therapy is usually withdrawn 2–6 weeks before such investigations. This precipitates a physiological rise in TSH, and therefore acts as a provocation test to facilitate detection of occult disease. In recent years, recombinant thyrotropin-α (Thyrogen®) given by intramuscular injection has been used for those individuals who do not have an adequate TSH response to hormone withdrawal, and for those where the transient myxoedema after hormone withdrawal is intolerable. A thyroglobulin level of >2 ng/mL 72 hours after TSH provocation usually warrants further investigation (neck ultrasound or MRI, CT scan of the thorax, whole body radioiodine scan) to exclude local relapse and distant metastatic disease.
Defects in Tg Gene Expression and Tg Secretion
Geraldo Medeiros-Neto, John Bruton Stanbury in Inherited Disorders of the Thyroid System, 2019
Thyroid hormone synthesis is intimately bound up with thyroglobulin (Tg). Indeed, after the active transport of iodide into the thyroid cell, every subsequent step of triiodothyronine (T3) and thyroxine (T4) formation occurs within the Tg molecule. Thus, synthesis of T3 and T4 follows a metabolic pathway that depends on the integrity of the Tg structure. This large glycoprotein, a dimer of 660,000 Da, is synthesized and secreted by the thyroid cells into the lumen of the thyroid follicle. Thyroglobulin serves two main purposes in the function of the thyroid gland. The first is related to the process of hormone production. Thus, Tg provides for the efficient coupling of the hormone precursors mono- and diiodotyrosine to form T3 and T4. The second function is that of a repository within the gland of a large supply of iodine and of hormone for secretion at a steady rate or upon demand.1 These two properties of Tg seem to permit the organism to operate in an environment that is usually deficient in iodine and to accommodate to wide variations in iodine supply. The efficiency of hormone synthesis in Tg depends on structural factors intrinsic to the protein matrix that favors the coupling reaction. We may assume that genetic mutations that would result in a structurally defective protein would severely impair the functional ability of Tg to serve as matrix for T3 and T4 generation.
Thyroid-dedicated internally-cooled wet electrode for benign thyroid nodules: experimental and clinical study
Published in International Journal of Hyperthermia, 2022
So Yeong Jeong, Jung Hwan Baek, Sae Rom Chung, Young Jun Choi, Ki-Wook Chung, Tae Yong Kim, Jeong Hyun Lee
The laboratory findings in the clinical study were as follows. The CBC and blood coagulation tests of all patients were normal at pretreatment evaluation. The initial mean TSH, fT4 and T3 were 2.1 ± 1.8 μU/ml (0.08–8.2), 1.3 ± 0.3 ng/dl (1.0–2.5) and 149.7 ± 23.0 ng/dl (116–202), respectively. The initial calcitonin and thyroglobulin were 2.1 ± 1.2 pg/ml (1.5–5.2) and 36.6 ± 52.1 ng/ml (1.5–233), respectively. In the initial laboratory test, eight patients had an elevated thyroglobulin level with a mean of 74.8 ± 67.4 ng/ml (range: 32.5–233). After RFA, thyroid function was well preserved in all patients, and the mean thyroglobulin level had significantly decreased to 26.9 ± 62.2 ng/ml at the 6-month follow-up (p=.046). Five out of the eight patients who had an initial elevated thyroglobulin level were normal on a 6-month follow-up after RFA.
2022 Expert consensus on the use of laser ablation for papillary thyroid microcarcinoma
Published in International Journal of Hyperthermia, 2022
Lu Zhang, Wei Zhou, Jian Qiao Zhou, Qian Shi, Teresa Rago, Giovanni Gambelunghe, Da Zhong Zou, Jun Gu, Man Lu, Fen Chen, Jie Ren, Wen Cheng, Ping Zhou, Stefano Spiezia, Enrico Papini, Wei Wei Zhan
Expert Recommendation 19: In the event of local hemorrhage, local pressure should be applied until the bleeding stops. Surgical consultation is needed in case of severe bleeding. Recommendation strength: strong recommendation; low quality evidence.3. Abnormal thyroid function is a minor complication after PLA. A transient increase of serum anti-thyroid antibodies and thyroglobulin levels may be observed. Delayed transient hyperthyroidism or hypothyroidism is rare and generally self-limiting [28]. If hyperthyroidism occurs, the majority of patients will spontaneously recover by avoiding iodine in their diet. Severe hyperthyroidism is treated using oral antithyroid drugs. If thyroid hormone surge occurs, levothyroxine tablets can be taken orally. Thyroid function should be monitored regularly in these patients, with dosage adjusted accordingly.
Toxicity from illegitimate slimming agents – a 10-year case series at a tertiary toxicology laboratory in Hong Kong
Published in Clinical Toxicology, 2021
Nike Kwai Cheung Lau, Magdalene Huen Yin Tang, Sau Wah Ng, Yeow Kuan Chong, Sammy Pak Lam Chen, Hencher Han Chih Lee, Chor Kwan Ching, Tony Wing Lai Mak
The use of thyroid tissue, thyroid hormones or their analogues for weight reduction was reported, either as an illegitimate practice or an undeclared adulterant [9,10,23]. Patients may present with severe consequences such as thyroid storm [6], cardiac arrest or even death [10]. In our study, these drugs were found in three of the six patients who presented with cardiac arrest. However, these patients were often taking multiple drugs so a definite causal role of thyroid hormone could not be established. However, the thyrotoxic state may compound the cardiotoxicity or electrolyte disturbance due to other concurrent slimming agents. Differentiation of thyrotoxicosis from sympathomimetic toxidrome with appropriate thyroid function tests would be essential. A low serum thyroglobulin would suggest an exogenous source of thyroid hormone [24].