Summary

Kabuki syndrome is a genetic disorder characterised by distinctive facial features, developmental delays, and multisystem congenital anomalies. Endocrine complications such as premature thelarche and short stature are common, whereas disorders of glycaemic control are less frequent. We describe a 23-year-old white female referred to the diabetes clinic for hyperglycaemia during haemodialysis. She was subsequently diagnosed with Kabuki syndrome based on characteristic clinical features, confirmed by detecting a heterozygous pathogenic variant in KMT2D. She was known to have had multiple congenital anomalies at birth, including complex congenital heart disease and a single dysplastic ectopic kidney, and received a cadaveric transplanted kidney at the age of 13. She had hyperglycaemia consistent with post-transplant diabetes mellitus (DM) and was started on insulin. Examination at the time revealed truncal obesity. She developed acute graft rejection and graft failure 14 months post-transplant and she was started on haemodialysis. Her blood glucose levels normalised post-graft explant, but she was hyperglycaemic again during haemodialysis at the age of 23. Given her clinical phenotype, negative diabetes antibodies and normal pancreas on ultrasound, she was assumed to have type 2 DM and achieved good glycaemic control with gliclazide.

Learning points

• Involve clinical genetics early in the investigative pathway of sick neonates born with multiple congenital anomalies to establish a diagnosis to direct medical care.

• Consider the possibility of Kabuki syndrome (KS) in the differential diagnoses in any neonate with normal karyotyping or microarray analysis and with multiple congenital anomalies (especially cardiac, renal, or skeletal), dysmorphic facial features, transient neonatal hypoglycaemia and failure to thrive.

• Consider the possibility of diabetes as an endocrine complication in KS patients who are obese or who have autoimmune disorders.

Summary

Non-islet cell tumour hypoglycemia (NICTH), typically mediated by insulin-like growth factor 2 (IGF-2), is a rare but highly morbid paraneoplastic syndrome associated with tumours of mesenchymal or epithelial origin. Outside of dextrose administration and dietary modification which provide transient relief of hypoglycemia, resection of the underlying tumour is the only known cure for NICTH. Available medical therapies to manage hypoglycemia include glucocorticoids, recombinant growth hormone, and pasireotide. We report two cases of IGF-2 mediated hypoglycemia. The first was managed surgically to good effect, highlighting the importance of a timely diagnosis to maximise the likelihood of a surgical cure. The second patient had unresectable disease and was managed medically, adding to a growing number of cases supporting the efficacy of glucocorticoids and recombinant growth hormone in NICTH.

Learning points

• Recurrent fasting hypoglycemia in the setting of a malignancy should raise suspicion of non-islet cell tumour hypoglycemia (NICTH), which is typically mediated by IGF-2.

• The initial workup for NICTH should include a serum glucose, C-peptide, insulin, insulin antibodies, beta-hydroxybutyrate, IGF-2, IGF-1, and sulphonylurea screen during a spontaneous or induced hypoglycemic episode.

• An IGF-2/IGF-1 ratio above 10 is highly suggestive of IGF-2-mediated hypoglycemia if the IGF-2 level is normal or elevated. False positives may be seen with sepsis and cachexia as both IGF-2 and IGF-1 are subnormal in these cases. A low IGF binding protein 3 (IGFBP3), such as in renal failure, may also result in a falsely normal or low IGF-2/IGF-1 ratio.

• Surgical resection of the associated tumour is curative in most NICTH cases.

• When the tumour is unresectable, moderate-dose glucocorticoids, low-dose glucocorticoids in combination with recombinant growth hormone, and pasireotide are medical therapies with promising results in controlling NICTH.

Summary

Functioning gonadotroph adenomas with clinical manifestations are extremely rare and the majority of these are FSH-secreting macroadenomas. Clinical symptoms are due to excess gonadotrophins and sex hormones, and these may be present for a long time before the diagnosis of pituitary adenoma is made. We present the case of a 37-year-old Caucasian male with clinical manifestations of an FSH-secreting pituitary macroadenoma. He had sexual dysfunction for a year followed by bilateral testicular pain and enlargement which was initially treated as suspected recurrent epididymitis, but his symptoms did not resolve. He presented a year later with headaches and bilateral superior temporal visual field defects. Brain imaging confirmed a pituitary macroadenoma with optic chiasm compression. Pituitary profile demonstrated an unusually high FSH with high normal LH and normal testosterone level. The patient successfully underwent transsphenoidal hypophysectomy and histology confirmed gonadotroph differentiation and immunoreactivity predominantly with FSH. Gonadotrophin levels and testosterone dropped significantly after surgery, and he was started on testosterone replacement. MR imaging, 2 years post surgery, showed no recurrence of pituitary adenoma. In conclusion, testicular enlargement and hypogonadal symptoms associated with low testosterone levels are recognised features in FSH-secreting pituitary adenomas. Our patient had hypogonadal symptoms but consistently high normal testosterone levels prior to surgery. The reason for low libido despite high testosterone is unclear. Our case highlights the need to suspect such rare underlying pituitary pathology when dealing with unusual combinations of hypogonadal symptoms, testicular enlargement with low or normal testosterone levels.

Learning points

• Functioning pituitary adenomas that secrete excess follicle-stimulating hormone (FSH) are very rare and often present with symptoms related to pituitary mass effect.

• Testicular enlargement alongside sexual dysfunction are commonly reported symptoms amongst male patients.

• Pituitary profile results demonstrate a raised FSH level with either a low, normal, or even high testosterone level which may not always correlate to clinical symptoms.

• Pituitary pathology should be considered in males presenting with unusual combinations of testicular enlargement and hypogonadal symptoms even with normal testosterone levels.

Summary

The use of a low-carbohydrate diet (LCD) reduces insulin requirements in insulinopenic states such as type 1 diabetes mellitus (T1DM). However, the use of potentially ketogenic diets in this clinical setting is contentious and the mechanisms underlying their impact on glycaemic control are poorly understood. We report a case of a patient with a late-onset classic presentation of T1DM who adopted a very low-carbohydrate diet and completely avoided insulin therapy for 18 months, followed by tight glycaemic control on minimal insulin doses. The observations suggest that adherence to an LCD in T1DM, implemented soon after diagnosis, can facilitate an improved and less variable glycaemic profile in conjunction with temporary remission in some individuals. Importantly, these changes occurred in a manner that did not lead to a significant increase in blood ketone (beta-hydroxybutyrate) concentrations. This case highlights the need for further research in the form of randomised controlled trials to assess the long-term safety and sustainability of carbohydrate-reduced diets in T1DM.

Learning points

• This case highlights the potential of low-carbohydrate diets (LCDs) in type 1 diabetes mellitus (T1DM) to mediate improved diabetes control and possible remission soon after diagnosis.

• Could carbohydrate-reduced diets implemented early in the course of T1DM delay the decline in endogenous insulin production?

• Adherence to an LCD in T1DM can facilitate an improved and less variable glycaemic profile.

• This case suggests that LCDs in T1DM may not be associated with a concerning supraphysiological ketonaemia.

Summary

We report the case of a male patient with papillary thyroid cancer, familial thoracic aortic aneurysm and dissection, and a variation in the MYH11 gene. Because of considerable tumor bulk in the neck that was not resectable, the patient underwent partial resection at age 14 years. Since then, the patient has received only suppressive thyroid hormone therapy. He is now 71 years old, which is 57 years after the initial resection. The patient received care at our institution from July 2009 to August 2019, during which we documented the stability of multiple calcified masses in the neck. Follow-up examinations at another institution from September 2019 to April 2023 also confirmed the stability of the masses. The underlying cause of this unusually long indolent course of the disease is unclear. Whether extensive tumor calcifications or the MYH11 sequence variation contributed to the disease course is also uncertain.

Learning points

• Papillary thyroid cancer with neck metastases may, in some cases, be stable and remain asymptomatic for decades.

• If locoregional stability of papillary thyroid cancer is documented for many years, observation may be preferable to extensive neck surgery in selected cases.

• This is the first report of an MYH11 gene alteration and thoracic aortic aneurysm in a patient with papillary thyroid cancer with indolent neck metastases.

• Future studies of MYH11 gene alterations in thyroid carcinoma are needed.

Summary

Thyroid metastases from nonthyroidal malignancies (NTMs) represent a diagnostic challenge, often displaying heterogeneous clinical manifestations. These metastases are rare but significant, accounting for approximately 2% of thyroid malignancies. Distinguishing them from primary thyroid malignancies is challenging due to the lack of specific ultrasound features, and the ultrasound-based risk stratification systems offer limited utility in such cases. Fine needle aspiration cytology is crucial for definitive diagnosis, yet it may not always provide accurate results. In this case report, we describe a unique instance of thyroid metastases originating from renal cell carcinoma, emphasizing the complexities in diagnosis and the importance of considering oncological conditions when assessing thyroid masses. Awareness of thyroid metastasis from NTMs, particularly in cases of diffuse thyroid hypoechogenicity and hypothyroidism, is essential for clinicians in their diagnostic approach.

Learning points

• Thyroid metastases from nonthyroidal malignancies are diagnostic challenges due to their heterogeneous clinical presentations, often mimicking primary thyroid malignancies.

• Thyroid metastases from nonthyroidal malignancies are relatively rare, but they still account for approximately 2% of thyroid malignancies.

• It is fundamental to consider oncological conditions when assessing thyroid masses, especially in cases of diffuse thyroid hypoechogenicity, hypothyroidism, and history of other tumors.

• Thyroid presentation is quite similar to that of autoimmune hypothyroidism, endocrinologists must be aware of the possibility of thyroid hypofunction due to the massive invasion of the parenchyma.

Summary

Unlike medullary thyroid carcinomas, follicular cell-derived thyroid malignancies have rarely been associated with paraneoplastic endocrine syndromes. An ultrarare case of a middle-aged man with heavily treated broadly metastatic radioactive iodine-refractory widely invasive Hürthle cell carcinoma (HCC) of the thyroid with two synchronous paraneoplastic endocrine syndromes, T3 thyrotoxicosis and hypercalcemia of malignancy, is discussed here. The levothyroxine-induced T3 thyrotoxicosis was a gradual process that became more noticeable as the tumor burden, refractory to different modalities of therapy, expanded. The 1,25-dihydroxyvitamin-D-mediated hypercalcemia, on the other hand, developed in a manner of weeks, as it usually happens. It is important to emphasize that in patients with metastatic Hürthle cell and follicular carcinomas of the thyroid, on TSH suppressive therapy, the unexplained and progressive decline in FT4 and rise in FT3 levels, resulting in an elevated FT4/FT3 ratio, could be an indication of augmented type 1 (D1) and/or type 2 (D2) deiodinase expression in tumoral tissue, causing an increased conversion from the prohormone T4 into the active metabolite T3 via outer ring deiodination.

Learning points

• Albeit extremely rare, some patients with thyroid cancer can present with more than one concomitant paraneoplastic syndrome.

• Although medullary thyroid carcinoma is the thyroid malignancy that is usually associated with paraneoplastic endocrine syndromes, follicular cell-derived thyroid cancers have been rarely described as being the culprit.

• In patients with metastatic Hürthle cell and follicular thyroid carcinomas, the unexplained and progressive decline in FT4 and rise in FT3 levels could be an indication of augmented type 1 (D1) and/or type 2 (D2) deiodinase expression in tumoral tissue, causing an increased conversion from T4 into T3 leading to T3 thyrotoxicosis.

Summary

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can impair pituitary–gonadal axis and a higher prevalence of hypogonadism in post-coronavirus disease 2019 (COVID-19) patients compared with the general population has been highlighted. Here we report the first case of a patient affected with a long-COVID syndrome leading to hypogonadism and treated with testosterone replacement therapy (TRT) and its effects on clinical and quality of life (QoL) outcomes. We encountered a 62-year-old man who had been diagnosed with hypogonadotropic hypogonadism about 2 months after recovery from COVID-19 underwent a complete physical examination, general and hormonal blood tests, and self-reported questionnaires administration before and after starting TRT. Following the TRT, both serum testosterone level and hypogonadism-related symptoms were improved, but poor effects occurred on general and neuropsychiatric symptoms and QoL. Therefore, hypogonadism does not appear to be the cause of neurocognitive symptoms, but rather a part of the long-COVID syndrome; as a consequence, starting TRT can improve the hypogonadism-related symptoms without clear benefits on general clinical condition and QoL, which are probably related to the long-COVID itself. Longer follow-up might clarify whether post-COVID hypogonadism is a transient condition that can revert as the patient recovers from long-COVID syndrome.

Learning points

• Hypogonadism is more prevalent in post-COVID-19 patients compared with the general population.

• In these patients, hypogonadism may be part of long-COVID syndrome, and it is still unclear whether it is a transient condition or a permanent impairment of gonadal function.

• Testosterone replacement therapy has positive effects on hypogonadism-related clinic without clear benefits on general symptomatology and quality of life, which are more likely related to the long-COVID itself.

Summary

Pheochromocytomas are rare adrenal tumors characterized by excessive catecholamine secretion. Symptoms and signs associated with pheochromocytomas are usually intermittent and chronic but can rarely develop into life-threatening crises. We describe a case of acute severe congestive heart failure in a previously healthy female, who recovered rapidly (4 days after admission) with acute medical therapy. The etiology on evaluation was a spontaneous bleed in a previously undiagnosed pheochromocytoma, resulting in a pheochromocytoma crisis and transient stress cardiomyopathy, followed by quick recovery of cardiac function. Our aim is to describe pheochromocytoma as a rare cause of stress cardiomyopathy. We discuss the evaluation of pheochromocytoma during critical illness and triggers/treatment strategies for pheochromocytoma crises.

Learning points

• Hemorrhage in a pheochromocytoma can result in a pheochromocytoma crisis, with sudden release of excess catecholamines resulting in multisystem organ dysfunction and high mortality.

• Acute decompensated heart failure can be a rare presentation of pheochromocytoma, in a patient with no cardiac risk factors.

• Measurement of metanephrines in acutely stressful clinical situations can have considerable overlap with the biochemical picture of pheochromocytoma. Early imaging studies may help with the differential diagnosis.

• Pheochromocytoma should be ruled out before performing an adrenal biopsy.

• Emergent adrenalectomy in pheochromocytoma crisis results in high mortality. Medical management of the acute crisis followed by elective adrenalectomy after alpha-blockade results in better outcomes.

Summary

Barakat syndrome, also called HDR syndrome, is a rare genetic disorder encompassing hypoparathyroidism (H), sensorineural deafness (D) and renal disease (R). A 64-year-old woman was referred to our endocrinology clinic for a switch in treatment (from dihydrotachysterol to calcitriol). She had progressive sensorineural deafness since the age of 18 and idiopathic hypoparathyroidism diagnosed at age of 36. Her medical history included osteoporosis with hip/spine fractures, nephrolithiasis and a family history of hearing loss, osteoporosis and kidney disease. The patient’s clinical presentation indicated Barakat syndrome. Genetic analysis found a GATA3:c.916C>T nonsense variant. Further tests such as audiometry, labs and renal imaging supported the diagnosis. Due to rarity and manifold symptoms, diagnosis can be challenging. Optional GATA3 testing was suggested in 2018, except in cases of isolated sensorineural deafness or renal disease with pertinent family history. In isolated ‘H’ cases without ‘D’ and ‘R’, GATA3 studies are not required, as no haploinsufficiency cases were reported. Given the rise in genetic disorders, physicians should consistently consider rare genetic disorders in patients with suggestive symptoms, even decades after onset. Although diagnosis might not always impact management directly, it aids patients in accepting their condition and has broader family implications.

Learning points

• There is currently an important increase in genetic and clinical characterization of new orphan diseases and their causative agents.

• Unbiased re-evaluation for possible genetic disorders is necessary at every consultation.

• It is essential to recognize the differential diagnosis of idiopathic hypoparathyroidism.

• The patient’s clinical presentation and family history can be important to establish the correct diagnosis.

• Physicians should not hesitate to search a patient’s signs and symptoms online.