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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

Natassia Rodrigo and Samantha Hocking

Summary

This case illustrates the exceedingly rare phenomenon of transient diabetes insipidus, in association with pre-eclampsia, occurring in the post-partum period following an in vitro fertilisation pregnancy, in an otherwise well 48-year-old lady. Diabetes insipidus can manifest during pregnancy, induced by increased vasopressinase activity secreted by placental trophoblasts and usually manifests in the third trimester. This presentation elucidates not only the intricate balance between the physiology of pregnancy and hormonal homeostasis, but also the importance of post-partum care as the physiological changes of pregnancy still hold pathological potential in the weeks immediately following delivery.

Learning points:

  • Diabetes insipidus (DI) is a rare complication of pregnancy occurring in 1 in 30 000 pregnancies.

  • It is associated with excessive vasopressinase activity, secreted by placental trophoblasts, which increases the rate of degradation of anti-diuretic hormone.

  • It is responsive to synthetic desmopressin 1-deanimo-8-d-arginine vasopressin as this form is not degraded by placental vasopressinase.

  • Vasopressinase is proportional to placental weight, which is increased in pregnancies conceived with assisted reproductive techniques including in vitro fertilisation.

  • Vasopressinase-induced DI is associated with pre-eclampsia.

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

Catherine Alguire, Jessica Chbat, Isabelle Forest, Ariane Godbout and Isabelle Bourdeau

Summary

Pheochromocytoma is a rare tumor of the adrenal gland. It often presents with the classic triad of headache, palpitations and generalized sweating. Although not described as a typical symptom of pheochromocytoma, anxiety is the fourth most common symptom reported by patients suffering of pheochromocytoma. We report the case of a 64 year old man who had severe anxiety and panic disorder as presenting symptoms of pheochromocytoma. After 13 years of psychiatric follow-up, the patient was diagnosed with malignant pheochromocytoma. After surgical resection of his pheochromocytoma and his hepatic metastases, the major panic attacks completely disappeared, the anxiety symptoms improved significantly and the psychiatric medications were stopped except for a very low maintenance dose of venlafaxine. We found in our cohort of 160 patients with pheochromocytoma 2 others cases of apparently benign tumors with severe anxiety that resolved after pheochromocytoma resection. These cases highlight that pheochromocytoma should be included in the differential diagnosis of refractory anxiety disorder.

Learning points:

  • Anxiety and panic disorder may be the main presenting symptoms of pheochromocytoma.

  • The diagnosis of pheochromocytoma should be excluded in cases of long-term panic disorder refractory to medications since the anxiety may be secondary to a catecholamine-secreting tumor.

  • Surgical treatment of pheochromocytoma leads to significant improvement of anxiety disorders.

Open access

Cheuk-Lik Wong, Chun-Kit Fok and Vicki Ho-Kee Tam

Summary

We report a case of elderly Chinese lady with neurofibromatosis type-1 presenting with longstanding palpitation, paroxysmal hypertension and osteoporosis. Biochemical testing showed mild hypercalcaemia with non-suppressed parathyroid hormone level suggestive of primary hyperparathyroidism, and mildly elevated urinary fractionated normetanephrine and plasma-free normetanephrine pointing to a catecholamine-secreting pheochromocytoma/paraganglioma. Further scintigraphic investigation revealed evidence of a solitary parathyroid adenoma causing primary hyperparathyroidism and a left pheochromocytoma. Resection of the parathyroid adenoma and pheochromocytoma resulted in normalization of biochemical abnormalities and hypertension. The rare concurrence of primary hyperparathyroidism and pheochromocytoma in neurofibromatosis type-1 is discussed.

Learning points:

  • All NF-1 patients who have symptoms suggestive of a pheochromocytoma/paraganglioma (PPGL), even remotely, should undergo biochemical testing.

  • The initial biochemical tests of choice for PPGL in NF-1 are either plasma-free metanephrines or urinary fractionated metanephrines. Any elevations of metanephrines should be carefully evaluated for the presence of PPGLs in NF-1 patients.

  • Primary hyperparathyroidism (PHPT) is described in subjects with NF-1. Due to the lack of epidemiological and functional studies, their association is yet to be substantiated. Meanwhile, PHPT may further exacerbate the metabolic bone defect in these patients and should be treated when present according to published guidelines.

  • Coexistence of PPGL and PHPT can occur in subjects with NF-1, mimicking multiple endocrine neoplasia type 2 (MEN2).

Open access

V Larouche and M Tamilia

Summary

Enteroviruses, including coxsackieviruses and Echovirus, are well known pathogens responsible for the development of thyroiditis. We describe the case of a 49-year-old woman with no personal or family history of thyroid disease who presented to the emergency room with a two-week history of daily fevers up to 39°C, a sore throat, occasional palpitations and diaphoresis, decreased appetite and an unintentional 10 kg weight loss over the same time course Physical examination revealed mild tachycardia, an intention tremor and a normal-sized, nontender thyroid gland without palpable nodules. The remainder of the physical examination was unremarkable and without stigmata of Graves’ disease. Her initial blood tests revealed overt thyrotoxicosis, elevated liver enzymes, an elevated C-reactive protein, a negative monospot and a positive CMV IgM antibody. Thyroid sonography revealed areas of hypoechogenicity and relatively low vascularity. Fine-needle biopsy showed a lymphocytic infiltrate. The patient was treated symptomatically with propranolol. On follow-up, the patient became euthyroid, and her liver enzymes normalised. Previous cases of CMV-induced thyroiditis occurred in immunosuppressed patients. This is the first reported case of a CMV-mononucleosis-induced thyroiditis in an immunocompetent adult patient and serves as a reminder that viral illnesses are a common cause of thyroiditis with abnormal liver enzymes.

Learning points:

  • The differential diagnosis of thyrotoxicosis with abnormal liver enzymes includes severe hyperthyroidism and thyroid storm caused by Graves’ disease as well as the thyrotoxic phase of a thyroiditis, usually caused by a virus such as coxsackievirus or, in this case, cytomegalovirus.

  • Cytomegalovirus appears to be a recently recognized causal agent for thyroiditis, both in immunosuppressed and immunocompetent patients.

  • Careful follow-up of thyroid function tests in patients with thyroiditis allows clinicians to determine if patients’ thyroid hormone secretion normalizes or if they remain hypothyroid.

Open access

Colin L Knight, Shamil D Cooray, Jaideep Kulkarni, Michael Borschmann and Mark Kotowicz

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.

Open access

R D’Arcy, M McDonnell, K Spence and C H Courtney

Summary

A 42-year-old male presented with a one-week history of palpitations and sweating episodes. The only significant history was of longstanding idiopathic dilated cardiomyopathy. Initial ECG demonstrated a sinus tachycardia. Thyroid function testing, undertaken as part of the diagnostic workup, revealed an un-measureable thyroid-stimulating hormone (TSH) and free thyroxine (T4). Upon questioning the patient reported classical thyrotoxic symptoms over the preceding weeks. Given the persistence of symptoms free tri-iodothyronine (T3) was measured and found to be markedly elevated at 48.9 pmol/L (normal range: 3.1–6.8 pmol/L). No goitre or nodular disease was palpable in the neck. Historically there had never been any amiodarone usage. Radionucleotide thyroid uptake imaging (123I) demonstrated significantly reduced tracer uptake in the thyroid. Upon further questioning the patient reported purchasing a weight loss product online from India which supposedly contained sibutramine. He provided one of the tablets and laboratory analysis confirmed the presence of T3 in the tablet. Full symptomatic resolution and normalised thyroid function ensued upon discontinuation of the supplement.

Learning points:

  • Free tri-iodothyronine (T3) measurement may be useful in the presence of symptoms suggestive of thyrotoxicosis with discordant thyroid function tests.

  • Thyroid uptake scanning can be a useful aid to differentiating exogenous hormone exposure from endogenous hyperthyroidism.

  • Ingestion of thyroid hormone may be inadvertent in cases of exogenous thyrotoxicosis.

  • Medicines and supplements sourced online for weight loss may contain thyroxine (T4) or T3 and should be considered as a cause of unexplained exogenous hyperthyroidism.

Open access

Maria Mercedes Pineyro, Daiana Arrestia, Mariana Elhordoy, Ramiro Lima, Saul Wajskopf, Raul Pisabarro and Maria Pilar Serra

Summary

Spontaneous reossification of the sellar floor after transsphenoidal surgery has been rarely reported. Strontium ranelate, a divalent strontium salt, has been shown to increase bone formation, increasing osteoblast activity. We describe an unusual case of a young patient with Cushing’s disease who was treated with strontium ranelate for low bone mass who experienced spontaneous sellar reossification after transsphenoidal surgery. A 21-year-old male presented with Cushing’s features. His past medical history included delayed puberty diagnosed at 16 years, treated with testosterone for 3 years without further work-up. He was diagnosed with Cushing’s disease initially treated with transsphenoidal surgery, which was not curative. The patient did not come to follow-up visits for more than 1 year. He was prescribed strontium ranelate 2 g orally once daily for low bone mass by an outside endocrinologist, which he received for more than 1 year. Two years after first surgery he was reevaluated and persisted with active Cushing’s disease. Magnetic resonance image revealed a left 4 mm hypointense mass, with sphenoid sinus occupation by a hyperintense material. At repeated transsphenoidal surgery, sellar bone had a very hard consistency; surgery was complicated and the patient died. Sellar reossification negatively impacted surgery outcomes in this patient. While this entity is possible after transsphenoidal surgery, it remains unclear whether strontium ranelate could have affected sellar ossification.

Learning points:

  • Delayed puberty can be a manifestation of Cushing’s syndrome. A complete history, physical examination and appropriate work-up should be performed before initiating any treatment.

  • Sellar reossification should always be taken into account when considering repeated transsphenoidal surgery. Detailed preoperative evaluation of bony structures by computed tomography ought to be performed in all cases of reoperation.

  • We speculate if strontium ranelate may have affected bone mineralization at the sellar floor. We strongly recommend that indications for prescribing this drug should be carefully followed.