Clinical Overview > Hormone > Triiodothyronine (T3)
You are looking at 21 - 30 of 59 items
Search for other papers by Yew Wen Yap in
Google Scholar
PubMed
Search for other papers by Steve Ball in
Google Scholar
PubMed
Search for other papers by Zubair Qureshi in
Google Scholar
PubMed
Summary
The coexistence of primary hypothyroidism and thyroid-stimulating hormone (TSH)-stimulating pituitary macroadenoma can be a rare occurrence and can make diagnosis very challenging. We describe a case of a 44-year-old female with a history of fatigue, poor concentration, weight gain and amenorrhoea together with biochemical evidence of primary autoimmune hypothyroidism. Her initial TSH levels were elevated with low normal free thyroxine (T4) levels. Levothyroxine treatment was initiated and the dose was gradually titrated to supraphysiologic doses. This led to the normalisation of her TSH levels but her free T4 and triiodothyronine (T3) levels remained persistently elevated. This prompted a serum prolactin check which returned elevated at 2495 µ/L, leading onto pituitary imaging. A MRI of the pituitary gland revealed a pituitary macroadenoma measuring 2.4 × 2 × 1.6 cm. Despite starting her on cabergoline therapy with a reduction in her prolactin levels, her TSH levels began to rise even further. Additional thyroid assays revealed that she had an abnormally elevated alpha subunit at 3.95 (age-related reference range <3.00). This corresponded to a thyroid-secreting hormone pituitary macroadenoma. She went on to have a transphenoidal hypophysectomy. Histology revealed tissues staining for TSH, confirming this to be a TSH-secreting pituitary macroadenoma. This case highlighted the importance of further investigations with thyroid assay interferences, heterophile antibodies, alpha subunit testing and anterior pituitary profile in cases of resistant and non-resolving primary hypothyroidism.
Learning points:
-
Levothyroxine treatment in primary hypothyroidism can potentially unmask the presence of a latent TSH-secreting pituitary macroadenoma, which can make diagnosis very challenging.
-
A high index of suspicion should prompt clinicians to further investigate cases of primary hypothyroidism which despite increasing doses of levothyroxine treatment with normalisation of TSH, the free T4 and T3 levels remain persistently elevated.
-
Clinicians should consider investigating for adherence to levothyroxine, thyroid assay interference, heterophile antibodies, TSH dilution studies, alpha subunit and anterior pituitary profile testing to further clarity the diagnosis in these patients.
-
Although coexistent cases of TSHoma with primary hypothyroidism are rare, it should always be in the list of differential diagnoses in cases of unresolving primary hypothyroidism.
Search for other papers by Kewan Hamid in
Google Scholar
PubMed
Search for other papers by Neha Dayalani in
Google Scholar
PubMed
Division of Pediatric Endocrinology, Hurley Children’s Hospital, Flint, Michigan, USA
Search for other papers by Muhammad Jabbar in
Google Scholar
PubMed
Division of Pediatric Hematology and Oncology, Hurley Children’s Hospital, Flint, Michigan, USA
Search for other papers by Elna Saah in
Google Scholar
PubMed
Summary
A 6-year-old female presented with chronic intermittent abdominal pain for 1 year. She underwent extensive investigation, imaging and invasive procedures with multiple emergency room visits. It caused a significant distress to the patient and the family with multiple missing days at school in addition to financial burden and emotional stress the child endured. When clinical picture was combined with laboratory finding of macrocytic anemia, a diagnosis of hypothyroidism was made. Although chronic abdominal pain in pediatric population is usually due to functional causes such as irritable bowel syndrome, abdominal migraine and functional abdominal pain. Hypothyroidism can have unusual presentation including abdominal pain. The literature on abdominal pain as the main presentation of thyroid disorder is limited. Pediatricians should exclude hypothyroidism in a patient who presents with chronic abdominal pain. Contrast to its treatment, clinical presentation of hypothyroidism can be diverse and challenging, leading to a delay in diagnosis and causing significant morbidity.
Learning points:
-
Hypothyroidism can have a wide range of clinical presentations that are often nonspecific, which can cause difficulty in diagnosis.
-
In pediatric patients presenting with chronic abdominal pain as only symptom, hypothyroidism should be considered by the pediatricians and ruled out.
-
In pediatric population, treatment of hypothyroidism varies depending on patients’ weight and age.
-
Delay in diagnosis of hypothyroidism can cause significant morbidity and distress in pediatrics population.
Search for other papers by Kate Laycock in
Google Scholar
PubMed
Search for other papers by Abhijit Chaudhuri in
Google Scholar
PubMed
Search for other papers by Charlotte Fuller in
Google Scholar
PubMed
Search for other papers by Zahra Khatami in
Google Scholar
PubMed
Search for other papers by Frederick Nkonge in
Google Scholar
PubMed
Search for other papers by Nemanja Stojanovic in
Google Scholar
PubMed
Summary
Hashimoto’s encephalopathy (HE) is rarely reported with only a few hundred cases published. Diagnosis is made in patients with an appropriate clinical picture and high antithyroperoxidase (anti-TPO) antibodies after infectious, toxic and metabolic causes of encephalopathy have been excluded. There is little objective data on the neurocognitive impairment in patients with HE and their improvement with treatment. We present the case of a 28-year-old woman with HE. Approach to management was novel as objective neuropsychological assessment was used to assess her clinical condition and response to treatment. Intravenous immunoglobulin (IVIg) as the first-line treatment instead of steroids. She responded well. The case illustrates that a different approach is required for the diagnosis and treatment of HE. A new diagnostic criteria is proposed that includes neurocognitive assessment, serum and CSF antibodies, an abnormal EEG and exclusion of other causes of encephalopathy. Furthermore, treatment should be tailored to the patient.
Learning points:
-
Neurocognitive assessment should be carried out to assess the extent of brain involvement in suspected Hashimoto’s encephalopathy pre- and post- treatment.
-
Treatment of Hashimoto’s encephalopathy should be tailored to the patient.
-
Unifying diagnostic criteria for Hashimoto’s encephalopathy must be established.
Search for other papers by Florence Gunawan in
Google Scholar
PubMed
Search for other papers by Elizabeth George in
Google Scholar
PubMed
Search for other papers by Adam Roberts in
Google Scholar
PubMed
Summary
Immune checkpoint inhibitors are the mainstay of treatment for advanced melanoma, and their use is being increasingly implicated in the development of autoimmune endocrinopathies. We present a case of a 52-year-old man with metastatic melanoma on combination nivolumab and ipilumimab therapy who developed concurrent hypophysitis, type 1 diabetes mellitus (T1DM) and diabetes insipidus. He presented prior to third cycle of combination treatment with a headache, myalgias and fatigue. Biochemistry and MRI pituitary confirmed anterior pituitary dysfunction with a TSH: 0.02 mU/L (0.5–5.5 mU/L), fT4: 5.2 pmol/L (11–22 pmol/L), fT3: 4.0 pmol/L (3.2–6.4 pmol/L), cortisol (12:00 h): <9 nmol/L (74–286 nmol/L), FSH: 0.7 IU/L (1.5–9.7 IU/L), LH: <0.1 IU/L (1.8–9.2 IU/L), PRL: 1 mIU/L (90–400 mIU/L), SHBG: 34 nmol/L (19–764 nmol/L) and total testosterone: <0.4 nmol/L (9.9–27.8 nmol/L). High-dose dexamethasone (8 mg) was administered followed by hydrocortisone, thyroxine and topical testosterone replacement. Two weeks post administration of the third cycle, he became unwell with lethargy, weight loss and nocturia. Central diabetes insipidus was diagnosed on the basis of symptoms and sodium of 149 mmol/L (135–145 mmol/L). Desmopressin nasal spray was instituted with symptom resolution and normalization of serum sodium. Three weeks later, he presented again polyuric and polydipsic. His capillary glucose was 20.8 mmol/L (ketones of 2.4 mmol), low C-peptide 0.05 nmol/L (0.4–1.5 nmol/L) and HbA1c of 7.7%. T1DM was suspected, and he was commenced on an insulin infusion with rapid symptom resolution. Insulin antibodies glutamic acid decarboxylase (GAD), insulin antibody-2 (IA-2) and zinc transporter-8 (ZnT8) were negative. A follow-up MRI pituitary revealed findings consistent with recovering autoimmune hypophysitis. Immunotherapy was discontinued based on the extent of these autoimmune endocrinopathies.
Learning points:
-
The most effective regime for treatment of metastatic melanoma is combination immunotherapy with nivolumab and ipilumimab, and this therapy is associated with a high incidence of autoimmune endocrinopathies.
-
Given the high prevalence of immune-related adverse events, the threshold for functional testing should be low.
-
Traditional antibody testing may not be reliable to identify early-onset endocrinopathy.
-
Routine screening pathways have yet to be adequately validated through clinical trials.
Search for other papers by Fernando Gomez-Peralta in
Google Scholar
PubMed
Search for other papers by Pablo Velasco-Martínez in
Google Scholar
PubMed
Search for other papers by Cristina Abreu in
Google Scholar
PubMed
Search for other papers by María Cepeda in
Google Scholar
PubMed
Search for other papers by Marta Fernández-Puente in
Google Scholar
PubMed
Summary
Methimazole (MMI) and propylthiouracil (PTU) are widely used antithyroid drugs (ATD) that have been approved for the treatment of hyperthyroidism. Hepatotoxicity may be induced by these drugs, though they exert dissimilar incidence rates of hepatotoxicity and, possibly, with different underlying pathogenic mechanisms. We report the case of a 55-year-old woman with no relevant medical history diagnosed with hyperthyroidism due to Graves’ disease, who developed two episodes of acute hepatitis concurrent with the consecutive administration of two different ATDs, first MMI and then PTU. Given the impossibility of administering ATDs, it was decided to perform a total thyroidectomy because the patient was found to be euthyroid at that point. Pathological anatomy showed diffuse hyperplasia and a papillary thyroid microcarcinoma of 2 mm in diameter. Subsequent clinical check-ups were normal. This case suggests the importance of regular monitoring of liver function for hyperthyroid patients. Due to the potential severity of this side effect, it is recommended to determine baseline liver function prior to initiation of treatment.
Learning points:
-
We present a rare case of two acute hepatitis episodes concurrent with two different consecutive ATD therapies.
-
Our results highlight the relevance of a liver function monitoring during the treatment with MMI or PTU.
-
A baseline assessment of the liver function before starting an ATD treatment should be recommendable.
Search for other papers by Tessa Glyn in
Google Scholar
PubMed
Search for other papers by Beverley Harris in
Google Scholar
PubMed
Search for other papers by Kate Allen in
Google Scholar
PubMed
Summary
We present the case of a 57-year-old lady who had a delayed diagnosis of central hypothyroidism on a background of Grave’s thyrotoxicosis and a partial thyroidectomy. During the twenty years following her partial thyroidectomy, the patient developed a constellation of symptoms and new diagnoses, which were investigated by numerous specialists from various fields, namely rheumatology, renal and respiratory. She developed significantly impaired renal function and raised creatine kinase (CK). She was also referred to a tertiary neurology service for investigation of myositis, which resulted in inconclusive muscle biopsies. Recurrently normal TSH results reassured clinicians that this did not relate to previous thyroid dysfunction. In 2015, she developed increased shortness of breath and was found to have a significant pericardial effusion. The clinical biochemist reviewed this lady’s blood results and elected to add on a free T4 (fT4) and free T3 (fT3), which were found to be <0.4 pmol/L (normal range (NR): 12–22 pmol/L) and 0.3 pmol/L (NR: 3.1–6.8 pmol/L), respectively. She was referred urgently to the endocrine services and commenced on Levothyroxine replacement for profound central hypothyroidism. Her other pituitary hormones and MRI were normal. In the following year, her eGFR and CK normalised, and her myositis symptoms, breathlessness and pericardial effusion resolved. One year following initiation of Levothyroxine, her fT4 and fT3 were in the normal range for the first time. This case highlights the pitfalls of relying purely on TSH for excluding hypothyroidism and the devastating effect the delay in diagnosis had upon this patient.
Learning points:
-
Isolated central hypothyroidism is very rare, but should be considered irrespective of previous thyroid disorders.
-
If clinicians have a strong suspicion that a patient may have hypothyroidism despite normal TSH, they should ensure they measure fT3 and fT4.
-
Laboratories that do not perform fT3 and fT4 routinely should review advice sent to requesting clinicians to include a statement explaining that a normal TSH excludes primary but not secondary hypothyroidism.
-
Thyroid function tests should be performed routinely in patients presenting with renal impairment or a raised CK.
Search for other papers by Mallika Bhat in
Google Scholar
PubMed
Search for other papers by Matty Mozzor in
Google Scholar
PubMed
Search for other papers by Savneek Chugh in
Google Scholar
PubMed
Search for other papers by Vamsi Buddharaju in
Google Scholar
PubMed
Search for other papers by Monica Schwarcz in
Google Scholar
PubMed
Search for other papers by Guy Valiquette in
Google Scholar
PubMed
Summary
We describe detailed administration of thyroidal and extrathyroidal doses of radioiodine to a patient with end-stage renal disease on hemodialysis. A thorough description of area under curve measurements in a patient with compromised renal function has rarely been described in the literature. Few publications have described thyroid cancer management of patients on hemodialysis, and we believe our management will aid in patient treatment in the future.
Learning points:
-
Scheduling of hemodialysis is important when administering radioactive iodine.
-
Treatment of thyroid cancer with radioiodine in patients with end-stage renal disease requires multidisciplinary approach coordinating dialysis, nuclear medicine and endocrinologists care.
-
Balancing ideal dosage of I131 and the timing of dialysis to insure maximal thyroidal uptake and minimal extra thyroidal I131 concentration is necessary.
Search for other papers by Wei Lin Tay in
Google Scholar
PubMed
Search for other papers by Wann Jia Loh in
Google Scholar
PubMed
Search for other papers by Lianne Ai Ling Lee in
Google Scholar
PubMed
Search for other papers by Chiaw Ling Chng in
Google Scholar
PubMed
Summary
We report a patient with Graves’ disease who remained persistently hyperthyroid after a total thyroidectomy and also developed de novo Graves’ ophthalmopathy 5 months after surgery. She was subsequently found to have a mature cystic teratoma containing struma ovarii after undergoing a total hysterectomy and salpingo-oophorectomy for an incidental ovarian lesion.
Learning points:
-
It is important to investigate for other causes of primary hyperthyroidism when thyrotoxicosis persists after total thyroidectomy.
-
TSH receptor antibody may persist after total thyroidectomy and may potentially contribute to the development of de novo Graves’ ophthalmopathy.
Search for other papers by Alex González Bóssolo in
Google Scholar
PubMed
Search for other papers by Michelle Mangual Garcia in
Google Scholar
PubMed
Search for other papers by Paula Jeffs González in
Google Scholar
PubMed
Search for other papers by Miosotis Garcia in
Google Scholar
PubMed
Search for other papers by Guillermo Villarmarzo in
Google Scholar
PubMed
Search for other papers by Jose Hernán Martinez in
Google Scholar
PubMed
Summary
Classical papillary thyroid microcarcinoma (PTMC) is a variant of papillary thyroid carcinoma (PTC) known to have excellent prognosis. It has a mortality of 0.3%, even in the presence of distance metastasis. The latest American Thyroid Association guidelines state that although lobectomy is acceptable, active surveillance can be considered in the appropriate setting. We present the case of a 37-year-old female with a history of PTMC who underwent surgical management consisting of a total thyroidectomy. Although she has remained disease-free, her quality of life has been greatly affected by the sequelae of this procedure. This case serves as an excellent example of how first-line surgical treatment may result more harmful than the disease itself.
Learning points:
-
Papillary thyroid microcarcinoma (PTMC) has an excellent prognosis with a mortality of less than 1% even with the presence of distant metastases.
-
Active surveillance is a reasonable management approach for appropriately selected patients.
-
Patients should be thoroughly oriented about the risks and benefits of active surveillance vs immediate surgical treatment. This discussion should include the sequelae of surgery and potential impact on quality of life, especially in the younger population.
-
More studies are needed for stratification of PTMC behavior to determine if conservative management is adequate for all patients with this specific disease variant.
Search for other papers by Colin L Knight in
Google Scholar
PubMed
Search for other papers by Shamil D Cooray in
Google Scholar
PubMed
Search for other papers by Jaideep Kulkarni in
Google Scholar
PubMed
Director of Otolaryngology, University Hospital Geelong, Geelong, Victoria, Australia
Search for other papers by Michael Borschmann in
Google Scholar
PubMed
Deakin University School of Medicine, Geelong, Victoria, Australia
Melbourne Clinical School-Western Campus, Department of Medicine, The University of Melbourne, St. Albans, Victoria, Australia
Search for other papers by Mark Kotowicz in
Google Scholar
PubMed
A 51 year old man presented with sepsis in the setting of thioamide-induced agranulocytosis. Empiric broad-spectrum antibiotics was followed by directed narrow-spectrum antibiotics, and his neutrophil count recovered with support from granulocyte-colony stimulating factor (G-CSF) analogue transfusions. After a brief period of multi-modal therapy for nine days including potassium iodide (Lugol’s iodine), cholestyramine, propanolol and lithium to temper his persisting hyperthyroidism, a total thyroidectomy was performed while thyroid hormone levels remained at thyrotoxic levels. Postoperative recovery was uncomplicated and he was discharged home on thyroxine. There is limited available evidence to guide treatment in this unique cohort of patients who require prompt management to avert impending clinical deterioration. This case report summarises the successful emergent control of thyrotoxicosis in the setting of thioamide-induced agranulocytosis complicated by sepsis, and demonstrates the safe use of multi-modal pharmacological therapies in preparation for total thyroidectomy.
Learning points:
-
Thioamide-induced agranulocytosis is an uncommon but potentially life-threatening complication of which all prescribers and patients need to be aware.
-
A multi-modal preoperative pharmacological approach can be successful, even when thioamides are contraindicated, when needing to prepare a thyrotoxic patient for semi-urgent total thyroidectomy.
-
There is not enough evidence to confidently predict the safe timing when considering total thyroidectomy in this patient cohort, and therefore it should be undertaken when attempts have first been made to safely reduce thyroid hormone levels.
-
Thyroid storm is frequently cited as a potentially severe complication of thyroid surgery undertaken in thyrotoxic patients, although the evidence does not demonstrate this as a common occurrence.