Significant cardiac disease complicating Graves' disease in previously healthy young adults

SUMMARY

Graves' disease is associated with tachydysrythmia, cardiac ischaemia and cardiomyopathy - all uncommon in young adults without previous cardiac disease. We present three young individuals who developed cardiac complications after periods of uncontrolled Graves' disease. Subject 1: A 34-year-old female had severe thyrotoxic symptoms for weeks. Investigations showed fT4: 98.4 (11-25 pmol/L), fT3: 46.9 (3.1-6.8 pmol/L), TSH <0.01 (0.27-4.2 mU/L) and thyrotrophin receptor antibody (TRAb): 34.8 (<0.9 U//l). She had appropriate treatment but several weeks later she became breathless despite improving thyroid function. Echocardiography showed a pericardial effusion of 2.9 cm. She responded well to steroids and NSAIDs but developed active severe Graves' orbitopathy after early total thyroidectomy. Subject 2: A 28-year-old male developed thyrotoxic symptoms (fT4: 38 pmol/L, fT3: 13.9 pmol/L, TSH <0.01 (for over 6 months) and TRAb: 9.3 U/L). One month after starting carbimazole, he developed acute heart failure (HF) due to severe dilated cardiomyopathy - EF 10-15%. He partially recovered after treatment - EF 28% and had early radioiodine treatment. Subject 3: A 42-year-old woman who had been thyrotoxic for several months (fT4: 54.3; fT3 >46.1; TSH <0.01; TRAb: 4.5) developed atrial fibrillation (AF) and heart failure. Echocardiography showed cardiomegaly - EF 29%. She maintains sinus rhythm following early total thyroidectomy (EF 50%). Significant cardiac complications may occur in previously fit young adults, who have had uncontrolled Graves' disease for weeks to months. Cardiac function recovers in the majority, but early definitive treatment should be discussed to avoid Graves' disease relapse and further cardiac decompensation.

LEARNING POINTS

Cardiac complications of Graves' disease are uncommon in young adults without previous cardiac disease. These complications may however occur if Graves' disease had been poorly controlled for several weeks or months prior to presentation. Persistent symptoms after adequate control should alert clinicians to the possibility of cardiac disease. Specific treatment of Graves' disease and appropriate cardiac intervention results in complete recovery in the majority and carries a good prognosis. Early definitive treatment should be offered to them to prevent cardiac decompensation at times of further relapse.

Propylthiouracil-induced antineutrophil cytoplasmic antibody-associated vasculitis and agranulocytosis in a patient with Graves' disease

SUMMARY

This case is the first to describe a patient who experienced concomitant agranulocytosis and anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis as an adverse effect of propylthiouracil treatment for Graves' disease. A 42-year-old female with Graves' disease presented to the emergency department (ED) with a 2-week history of fevers, night sweats, transient lower limb rash, arthralgia, myalgia and fatigue. She had been taking propylthiouracil for 18 months prior to presentation. On admission, agranulocytosis was evident with a neutrophil count of 0.36 × 109/L and immediately propylthiouracil was stopped. There was no evidence of active infection and the patient was treated with broad-spectrum antibodies and one dose of granulocyte colony-stimulation factor, resulting in a satisfactory response. On further investigation, ANCAs were positive with dual positivity for proteinase 3 and myeloperoxidase. There was no evidence of end-organ damage secondary to vasculitis, and the patient's constitutional symptoms resolved completely on discontinuation of the drug precluding the need for immunosuppressive therapy.

LEARNING POINTS

Continued vigilance and patient education regarding the risk of antithyroid drug-induced agranulocytosis is vital throughout the course of treatment. ANCA-associated vasculitis is a rare adverse effect of antithyroid drug use. Timely discontinuation of the offending drug is vital in reducing end-organ damage and the need for immunosuppressive therapy in drug-induced ANCA-associated vasculitis. Similarities in the pathogenesis of agranulocytosis and drug-induced ANCA-associated vasculitis may offer insight into an improved understanding of vasculitis and agranulocytosis.

Adrenocortical carcinoma masquerading as pheochromocytoma: a histopathologic dilemma

SUMMARY

Adrenocortical carcinoma (ACC) is an aggressive cancer that originates in the cortex of the adrenal gland and generally has a poor prognosis. ACC is rare but can be more commonly seen in those with cancer predisposition syndromes (e.g. Li-Fraumeni and Lynch Syndrome). The diagnosis of ACC is sometimes uncertain and it requires the use of precise molecular pathology; the differential diagnosis includes pheochromocytoma, adrenal adenoma, renal carcinoma, or hepatocellular carcinoma. We describe a case of a 57-year-old woman with Lynch Syndrome and metastatic ACC who was initially diagnosed as having pheochromocytoma. The tumor was first identified at 51 years of age by ultrasound followed by a CT scan. She underwent a left adrenalectomy, and the histopathology identified pheochromocytoma. Two years later, she had tumor recurrence with imaging studies showing multiple lung nodules. Following a wedge resection by video-assisted thoracoscopic surgery (VATS), histopathology was read as metastatic pheochromocytoma at one institution and metastatic ACC at another institution. She later presented to the National Institutes of Health (NIH) where the diagnosis of ACC was confirmed. Following her ACC diagnosis, she was treated with mitotane and pembrolizumab which were stopped due to side effects and progression of disease. She is currently receiving etoposide, doxorubicin, and cisplatin (EDP). This case highlights the importance of using a multi-disciplinary approach in patient care. Thorough evaluation of the tumor's pathology and analysis of the patient's genetic profile are necessary to obtain the correct diagnosis for the patient and can significantly influence the course of treatment.

LEARNING POINTS

Making the diagnosis of ACC can be difficult as the differential diagnosis includes pheochromocytoma, adrenal adenoma, renal carcinoma, or hepatocellular carcinoma. Patients with Lynch Syndrome should undergo surveillance for ACC as there is evidence of an association between Lynch Syndrome and ACC. Conducting a complete tumor immunoprofile and obtaining a second opinion is very important in cases of suspected ACC in order to confirm the proper diagnosis. A multi-disciplinary approach including genetic testing and a thorough evaluation of the tumor's pathology is imperative to ensuring that the patient receives an accurate diagnosis and the appropriate treatment.

Hypercalcitoninaemia in pseudohypo-parathyroidism type 1A and type 1B

Pseudohypoparathyroidism (PHP) is a heterogeneous group of rare endocrine disorders characterised by normal renal function and renal resistance to the action of the parathyroid hormone. Type 1A (PHP1A), which is the most common variant, also include developmental and skeletal defects named as Albright hereditary osteodystrophy (AHO). We present two cases, a 54- and a 33-year-old male diagnosed with PHP who were referred to us for persistently high levels of serum calcitonin. AHO and multinodular goitre were present in the 54-year-old male, while the second patient was free of skeletal deformities and his thyroid gland was of normal size and without nodular appearance. We performed GNAS molecular analysis (methylation status and copy number analysis by MS-MLPA) in genomic DNA samples for both patients. The analysis revealed a novel missense variant c.131T>G p.(Leu44Pro) affecting GNAS exon 1, in the patient with the clinical diagnosis of PHP1A. This amino acid change appears to be in accordance with the clinical diagnosis of the patient. The genomic DNA analysis of the second patient revealed the presence of the recurrent 3-kb deletion affecting the imprinting control region localised in the STX16 region associated with the loss of methylation (LOM) at the GNAS A/B differentially methylated region and consistent with the diagnosis of an autosomal dominant form of PHP type 1B (PHP1B). In conclusion, hypercalcitoninaemia may be encountered in PHP1A and PHP1B even in the absence of thyroid pathology. Learning points: We describe a novel missense variant c.131T>G p.(Leu44Pro) affecting GNAS exon 1 as the cause of PHP1A. Hypercalcitoninaemia in PHP1A is considered an associated resistance to calcitonin, as suggested by the generalised impairment of Gsα-mediated hormone signalling. GNAS methylation defects, as in type PHP1B, without thyroid pathology can also present with hypercalcitoninaemia.

Managing thymic enlargement in Graves' disease

Thymic enlargement (TE) in Graves' disease (GD) is often diagnosed incidentally when chest imaging is done for unrelated reasons. This is becoming more common as the frequency of chest imaging increases. There are currently no clear guidelines for managing TE in GD. Subject 1 is a 36-year-old female who presented with weight loss, increased thirst and passage of urine and postural symptoms. Investigations confirmed GD, non-PTH-dependent hypercalcaemia and Addison's disease (AD). CT scans to exclude underlying malignancy showed TE but normal viscera. A diagnosis of hypercalcaemia due to GD and AD was made. Subject 2, a 52-year-old female, was investigated for recurrent chest infections, haemoptysis and weight loss. CT thorax to exclude chest malignancy, showed TE. Planned thoracotomy was postponed when investigations confirmed GD. Subject 3 is a 47-year-old female who presented with breathlessness, chest pain and shakiness. Investigations confirmed T3 toxicosis due to GD. A CT pulmonary angiogram to exclude pulmonary embolism showed TE. The CT appearances in all three subjects were consistent with benign TE. These subjects were given appropriate endocrine treatment only (without biopsy or thymectomy) as CT appearances showed the following appearances of benign TE - arrowhead shape, straight regular margins, absence of calcification and cyst formation and radiodensity equal to surrounding muscle. Furthermore, interval scans confirmed thymic regression of over 60% in 6 months after endocrine control. In subjects with CT appearances consistent with benign TE, a conservative policy with interval CT scans at 6 months after endocrine control will prevent inappropriate surgical intervention. Learning points: Chest imaging is common in modern clinical practice and incidental anterior mediastinal abnormalities are therefore diagnosed frequently. Thymic enlargement (TE) associated with Graves' disease (GD) is occasionally seen in view of the above. There is no validated strategy to manage TE in GD at present. However, CT (or MRI) scan features of the thymus may help characterise benign TE, and such subjects do not require thymic biopsy or surgery at presentation. In them, an expectant 'wait and see' policy is recommended with GD treatment only, as the thymus will show significant regression 6 months after endocrine control.

An evolving spectrum of diabetes in a woman with GCK-MODY

Coexistence of autoimmune diabetes and maturity-onset diabetes of the young (MODY) is rare. We report the first case of coexisting latent autoimmune diabetes of adulthood (LADA) and glucokinase (GCK) MODY. A 32-year-old woman was treated with insulin for gestational diabetes at age 32 years; post-partum, her fasting blood glucose was 6.0 mmol/L and 2-h glucose was 11.8 mmol/L following an oral glucose tolerance test, and she was maintained on diet alone. Five years later, a diagnosis of LADA was made when she presented with fasting blood glucose of 20.3 mmol/L and HbA1C 125 mmol/mol (13.6%). GCK-MODY was identified 14 years later when genetic testing was prompted by identification of a mutation in her cousin. Despite multiple daily insulin injections her glycaemic control remained above target and her clinical course has been complicated by multiple episodes of hypoglycaemia with unawareness. Although rare, coexistence of latent autoimmune diabetes of adulthood and monogenic diabetes should be considered if there is a strong clinical suspicion, for example, family history. Hypoglycaemic unawareness developed secondary to frequent episodes of hypoglycaemia using standard glycaemic targets for LADA. This case highlights the importance of setting fasting glucose targets within the expected range for GCK-MODY in subjects with coexisting LADA. Learning points: We report the first case of coexisting latent autoimmune diabetes of adulthood (LADA) and GCK-MODY. It has been suggested that mutations in GCK may lead to altered counter-regulation and recognition of hypoglycaemia at higher blood glucose levels than patients without such mutation. However, in our case, hypoglycaemic unawareness developed secondary to frequent episodes of hypoglycaemia using standard glycaemic targets for LADA. This case highlights the importance of setting fasting glucose targets within the expected range for GCK-MODY in subjects with coexisting LADA to avoid hypoglycaemia.