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Open access

Ohoud Al Mohareb, Mussa H Al Malki, O Thomas Mueller and Imad Brema

Summary

Resistance to thyroid hormone-beta (RTHbeta) is a rare inherited syndrome characterized by variable reduced tissue responsiveness to the intracellular action of triiodothyronine (T3), the active form of the thyroid hormone. The presentation of RTHbeta is quite variable and mutations in the thyroid hormone receptor beta (THR-B) gene have been detected in up to 90% of patients. The proband was a 34-year-old Jordanian male who presented with intermittent palpitations. His thyroid function tests (TFTs) showed a discordant profile with high free T4 (FT4) at 45.7 pmol/L (normal: 12–22), high free T3 (FT3) at 11.8 pmol/L (normal: 3.1–6.8) and inappropriately normal TSH at 3.19 mIU/L (normal: 0.27–4.2). Work up has confirmed normal alpha subunit of TSH of 0.1 ng/mL (normal <0.5) and pituitary MRI showed no evidence of a pituitary adenoma; however, there was an interesting coincidental finding of partially empty sella. RTHbeta was suspected and genetic testing confirmed a known mutation in the THR-B gene, where a heterozygous A to G base change substitutes valine for methionine at codon 310. Screening the immediate family revealed that the eldest son (5 years old) also has discordant thyroid function profile consistent with RTHbeta and genetic testing confirmed the same M310V mutation that his father harbored. Moreover, the 5-year-old son had hyperactivity, impulsivity and aggressive behavior consistent with attention deficit hyperactivity disorder (ADHD). This case demonstrates an unusual co-existence of RTHbeta and partially empty sella in the same patient which, to our knowledge, has not been reported before.

Learning points:

  • We report the coincidental occurrence of RTHbeta and a partially empty sella in the same patient that has not been previously reported.

  • TFTs should be done in all children who present with symptoms suggestive of ADHD as RTHbeta is a common finding in these children.

  • The management of children with ADHD and RTHbeta could be challenging for both pediatricians and parents and the administration of T3 with close monitoring may be helpful in some cases.

  • Incidental pituitary abnormalities do exist in patients with RTHbeta, although extremely rare, and should be evaluated thoroughly and separately.

Open access

Haruhiro Sato and Yuichiro Tomita

Summary

Resistance to thyroid hormone (RTH), which is primarily caused by mutations in the thyroid hormone (TH) receptor beta (THRB) gene, is dominantly inherited syndrome of variable tissue hyposensitivity to TH. We herein describe a case involving a 22-year-old Japanese man with RTH and atrial fibrillation (AF) complaining of palpitation and general fatigue. Electrocardiography results revealed AF. He exhibited elevated TH levels and an inappropriately normal level of thyroid-stimulating hormone (TSH). Despite being negative for anti-TSH receptor antibody, thyroid-stimulating antibody and anti-thyroperoxidase antibody, the patient was positive for anti-thyroglobulin (Tg) antibody. Genetic analysis of the THRB gene identified a missense mutation, F269L, leading to the diagnosis of RTH. Normal sinus rhythm was achieved after 1 week of oral bisoprolol fumarate (5 mg/day) administration. After 3 years on bisoprolol fumarate, the patient had been doing well with normal sinus rhythm, syndrome of inappropriate secretion of TSH (SITSH) and positive titer of anti-Tg antibody.

Learning points:

  • Atrial fibrillation can occur in patients with RTH.

  • Only a few cases have been reported on the coexistence of RTH and atrial fibrillation.

  • No consensus exists regarding the management of atrial fibrillation in patients with RTH.

  • Administration of bisoprolol fumarate, a beta-blocker, can ameliorate atrial fibrillation in RTH.

Open access

Ehtasham Ahmad, Kashif Hafeez, Muhammad Fahad Arshad, Jimboy Isuga and Apostolos Vrettos

Summary

Primary hypothyroidism is a common endocrine condition, most commonly caused by autoimmune thyroiditis (Hashimoto’s disease) while Graves’ disease is the most common cause of hyperthyroidism. Hypothyroidism is usually a permanent condition in most patients requiring lifelong levothyroxine treatment. Transformation from Hashimoto’s disease to Graves’ disease is considered rare but recently been increasingly recognised. We describe a case of a 61-year-old lady who was diagnosed with hypothyroidism approximately three decades ago and treated with levothyroxine replacement therapy. Approximately 27 years after the initial diagnosis of hypothyroidism, she started to become biochemically and clinically hyperthyroid. This was initially managed with gradual reduction in the dose of levothyroxine, followed by complete cessation of the medication, but she remained hyperthyroid, ultimately requiring anti-thyroid treatment with Carbimazole. This case highlights that there should be a high index of suspicion for a possible conversion of hypothyroidism to hyperthyroidism, even many years after the initial diagnosis of hypothyroidism. To our knowledge, this case illustrates the longest reported time interval between the diagnosis of hypothyroidism until the conversion to hyperthyroidism.

Learning points:

  • Occurrence of Graves’ disease after primary hypothyroidism is uncommon but possible.

  • In this case, there was a time-lapse of almost 28 years and therefore this entity may not be as rare as previously thought.

  • Diagnosis requires careful clinical and biochemical assessment. Otherwise, the case can be easily confused for over-replacement of levothyroxine.

  • We suggest measuring both anti-thyroid peroxidase (TPO) antibodies and TSH receptor antibodies (TRAB) in suspected cases.

  • The underlying aetiology for the conversion is not exactly known but probably involves autoimmune switch by an external stimulus in genetically susceptible individuals.

Open access

Carolina Shalini Singarayar, Foo Siew Hui, Nicholas Cheong and Goay Swee En

Summary

Thyrotoxicosis is associated with cardiac dysfunction; more commonly, left ventricular dysfunction. However, in recent years, there have been more cases reported on right ventricular dysfunction, often associated with pulmonary hypertension in patients with thyrotoxicosis. Three cases of thyrotoxicosis associated with right ventricular dysfunction were presented. A total of 25 other cases of thyrotoxicosis associated with right ventricular dysfunction published from 1994 to 2017 were reviewed along with the present 3 cases. The mean age was 45 years. Most (82%) of the cases were newly diagnosed thyrotoxicosis. There was a preponderance of female gender (71%) and Graves’ disease (86%) as the underlying aetiology. Common presenting features included dyspnoea, fatigue and ankle oedema. Atrial fibrillation was reported in 50% of the cases. The echocardiography for almost all cases revealed dilated right atrial and or ventricular chambers with elevated pulmonary artery pressure. The abnormal echocardiographic parameters were resolved in most cases after rendering the patients euthyroid. Right ventricular dysfunction and pulmonary hypertension are not well-recognized complications of thyrotoxicosis. They are life-threatening conditions that can be reversed with early recognition and treatment of thyrotoxicosis. Signs and symptoms of right ventricular dysfunction should be sought in all patients with newly diagnosed thyrotoxicosis, and prompt restoration of euthyroidism is warranted in affected patients before the development of overt right heart failure.

Learning points:

  • Thyrotoxicosis is associated with right ventricular dysfunction and pulmonary hypertension apart from left ventricular dysfunction described in typical thyrotoxic cardiomyopathy.

  • Symptoms and signs of right ventricular dysfunction and pulmonary hypertension should be sought in all patients with newly diagnosed thyrotoxicosis.

  • Thyrotoxicosis should be considered in all cases of right ventricular dysfunction or pulmonary hypertension not readily explained by other causes.

  • Prompt restoration of euthyroidism is warranted in patients with thyrotoxicosis complicated by right ventricular dysfunction with or without pulmonary hypertension to allow timely resolution of the abnormal cardiac parameters before development of overt right heart failure.

Open access

Shigenori Nakamura, Teruyuki Masuda and Masatoshi Ishimori

Summary

We report a case of a 15-year-old girl with a midline neck mass that was first noted 2 or 3 years previously. She had been treated with levothyroxine (L-T4) for congenital hypothyroidism until 11 years of age. Ultrasonography revealed an atrophic right thyroid (1.0 × 1.6 × 2.6 cm in size) and a mass (2.3 × 1.0 × 3.5 cm in size) in the upper part of the neck. No left lobe of the thyroid was detected. On further evaluation, Tc-99m pertechnetate thyroid scintigraphy and CT showed ectopic thyroid tissue in the lingual region and infrahyoid region. Thus, she was diagnosed as having dual ectopic thyroid and thyroid hemiagenesis. The atrophic right thyroid was thought be non-functional. Treatment with L-T4 was started to reduce the size of the dual ectopic thyroid tissue. This may be the first reported case of dual ectopic thyroid associated with hemiagenesis detected only by ultrasonography.

Learning points:

  • Ultrasonography can confirm the presence or absence of orthotopic thyroid tissue in patients with ectopic thyroid.

  • The cause of congenital hypothyroidism should be examined.

  • Clinical manifestation of ectopic thyroid may appear when the treatment with L-T4 is discontinued.

  • Annual follow-up is needed in all children when their thyroid hormone replacement is stopped.

Open access

Kate Laycock, Abhijit Chaudhuri, Charlotte Fuller, Zahra Khatami, Frederick Nkonge and Nemanja Stojanovic

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.

Open access

Charlotte S Schömig, Marie-Ève Robinson and Julia E von Oettingen

Summary

Congenital hypothyroidism requires prompt treatment to prevent adverse health outcomes. Poor intestinal levothyroxine absorption can complicate management. We present a case of a term female newborn with necrotizing enterocolitis (NEC) requiring subtotal ileum resection. Congenital hypothyroidism was diagnosed by newborn screening. Treatment was complicated by intestinal malabsorption of levothyroxine. Intravenous levothyroxine substitution restored euthyroidism and supraphysiologic PO doses subsequently maintained a euthyroid state. After several months, the required levothyroxine dose was weaned down to typical recommended dosing. In conclusion, small bowel resection secondary to NEC may lead to malabsorption of oral levothyroxine. An intravenous levothyroxine dose of approximately 50% typical PO dosing is effective in providing rapid normalization of free T4 and TSH. High PO doses may be required to maintain euthyroidism. Close thyroid function monitoring and immediate therapy adjustment are essential as the individual absorption may vary widely. Normal absorption levels may be regained due to adaption of the neonatal intestines.

Learning points:

  • In neonates with malabsorption after ileum resection intravenous levothyroxine replacement should be used to provide normalization of free T4 and TSH.

  • Very high doses of up to 500% usual oral levothyroxine may be required to maintain euthyroidism. The estimated degree of malabsorption can be used to determine the initial dose.

  • Close thyroid function monitoring and immediate therapy adjustment are essential as the absorption and intestinal adaption may vary widely.

Open access

Leanne Hunt, Barney Harrison, Matthew Bull, Tim Stephenson and Amit Allahabadia

Summary

This case report reviews the rare condition of Riedel’s thyroiditis via a patient case. The report highlights the difficulties that one may encounter when managing such a case in regards to patient symptoms, side effects of medications and the relapsing nature of the condition. The case report also highlights novel treatment in the treatment of Riedel’s thyroiditis, rituximab, how this works and the resolution of symptoms that we have achieved with our patient on this treatment.

Learning points:

  • Riedel’s thyroiditis is characterised by chronic inflammation, which causes dense fibrosis in the thyroid gland.

  • Riedel’s thyroiditis can present with neck pain, dysphagia and dyspnoea with a firm, non-tender mass found on examination.

  • Riedel’s thyroiditis is part of the IgG4-related systemic disorders.

  • Rituximab is a monoclonal antibody that works against the protein CD20.

Open access

Sulaiman Haji Ali, K Aljenaee, W A Wan Mahmood and M Hatunic

Summary

Hypothyroidism is a recognized side effect of thalidomide drugs. We herein report a case of 83-year-old Irish female with a diagnosis of multiple myeloma and a background history of type 2 diabetes mellitus and hypertension. Our patient received pomalidomide and multiple courses of chemotherapy and achieved very good initial response for her multiple myeloma but subsequently she relapsed. She did not have any past history of thyroid disease or family history of thyroid disorders. Prior to treatment with pomalidomide, her thyroid function test was completely normal. She was commenced on pomalidomide in February 2017. Four weeks post treatment, she presented with worsening fatigue, and as a part of her workup, a thyroid function test was performed. Her free T4 was low at 7.2 pmol/L (reference range: 9.0–20.0) while her TSH was elevated at 44.7 mIU/L (reference range: 0.35–4.94). Pomalidomide treatment was terminated, and she was commenced on thyroid hormonal therapy replacement therapy with thyroxine with good clinical and biochemical response. Practitioners prescribing pomalidomide should be aware of this potential complication and patients who are receiving immunomodulatory drugs like pomalidomide should undergo regular thyroid hormone levels screen.

Learning points:

  • Overt hypothyroidism is a side effect of pomalidomide.

  • Thyroid function test should be included as a screening test with regular review in patients receiving pomalidomide.

  • Unexplained worsening fatigue in patients receiving pomalidomide should raise the possibility of overt hypothyroidism.

Open access

Tessa Glyn, Beverley Harris and Kate Allen

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.