Summary

Hypercalcaemia in pregnancy is uncommon, with associated adverse obstetric and perinatal outcomes for both the mother and the fetus. Determination of causality is central to its management. Diagnostic imaging techniques are limited during pregnancy and the diagnosis is made more complex by physiological changes in calcium and vitamin D homeostasis in pregnancy. Further, therapeutic options are limited due to safety considerations for the pregnant woman and the developing foetus. Three cases of hypercalcaemia in pregnancy will be presented, highlighting the distinct aetiologies and management strategies for hypercalcaemia in pregnancy and the importance of early measurement of serum calcium in pregnancy screening.

Learning points

• There are complex physiological changes in calcium balance in pregnancy, including increased calcium intestinal absorption and renal excretion.

• Hypercalcaemia in pregnancy is uncommon but has important potential maternal and foetal complications, making a compelling argument for routine antenatal, calcium screening.

• Identifying the cause of hypercalcaemia in pregnancy can be challenging due to the complex placental interplay in biochemical test interpretation and due to safety constraints restricting imaging and surgery.

• Acute medical management of hypercalcaemia must be considered in the context of both maternal and foetal well-being, along with gestational age and specific consideration for the safety of the developing fetus in late gestation.

Summary

In this case report, we describe the management of a patient who was admitted with an ectopic ACTH syndrome during the COVID pandemic with new-onset type 2 diabetes, neutrophilia and unexplained hypokalaemia. These three findings when combined should alert physicians to the potential presence of Cushing’s syndrome (CS). On admission, a quick diagnosis of CS was made based on clinical and biochemical features and the patient was treated urgently using high dose oral metyrapone thus allowing delays in surgery and rapidly improving the patient’s clinical condition. This resulted in the treatment of hyperglycaemia, hypokalaemia and hypertension reducing cardiovascular risk and likely risk for infection. Observing COVID-19 pandemic international guidelines to treat patients with CS has shown to be effective and offers endocrinologists an option to manage these patients adequately in difficult times.

Learning points

• This case report highlights the importance of having a low threshold for suspicion and investigation for Cushing’s syndrome in a patient with neutrophilia and hypokalaemia, recently diagnosed with type 2 diabetes especially in someone with catabolic features of the disease irrespective of losing weight.

• It also supports the use of alternative methods of approaching the diagnosis and treatment of Cushing’s syndrome during a pandemic as indicated by international protocols designed specifically for managing this condition during Covid-19.

Summary

Resistance to thyroid hormone (RTH) is a rare hereditary syndrome with impaired sensitivity to thyroid hormones (TH) and reduced intracellular action of triiodothyronine (T3) caused by genetic variants of TH receptor beta (TRB) or alpha (TRA). RTH type beta (RTHβ) due to dominant negative variants in the TRB gene usually occurs with persistent elevation of circulating free TH, non-suppressed serum TSH levels responding to a thyrotropin-releasing hormone (TRH) test, an absence of typical symptoms of hyperthyroidism and goiter. Here, we present a rare variant in the TRB gene reported for the first time in an Italian patient with generalized RTHβ syndrome. The patient showed elevated TH, with non-suppressed TSH levels and underwent thyroid surgery two different times for multinodular goiter. The genetic test showed a heterozygous mutation in exon 9 of the TRB gene resulting in the replacement of threonine (ACG) with methionine (ATG) at codon 310 (p.M310T). RTHβ syndrome should be considered in patients with elevated TH, non-suppressed TSH levels and goiter.

Learning points

• Resistance to thyroid hormone (RTH) is a rare autosomal dominant hereditary syndrome with impaired tissue responsiveness to thyroid hormones (TH).

• Diagnosis of RTH is usually based on the clinical finding of discrepant thyroid function tests and confirmed by a genetic test.

• RTH is a rare condition that must be considered for the management of patients with goiter, elevation of TH and non-suppressed serum TSH levels in order to avoid unnecessary treatments.

Summary

Middle ear adenomas with neuroendocrine features (ANEF) are rare, with an estimated 150 reported cases. They usually pursue an indolent clinical course. Four reported cases of middle ear ANEF with distant metastases were treated with surgery, external beam radiation therapy (EBRT) and chemotherapy. To date, no successful systemic treatment for malignant behaviour of this rare tumour has been reported. Long-acting somatostatin analogues (SSAs) and peptide receptor radionuclide therapy (PRRT) have been used in well-differentiated metastatic neuroendocrine tumours (NETs), but their use has never been described in cases of metastatic middle ear ANEF. We report two patients with grade 1 middle ear ANEF treated with surgery and EBRT. They had stable disease for several years, until clinical symptoms appeared and extensive metastases were detected on ⁶⁸Ga-DOTA⁰-Tyr³-octreotate (DOTATATE) PET/CT. Treatment with long-acting SSA was started, with stable disease for 1 year. Afterwards, despite undergoing local treatments, both patients presented progressive disease. Due to high-uptake metastases at ⁶⁸Ga-DOTATATE PET/CT, both cases underwent four cycles of PRRT with ¹⁷⁷Lu-DOTATATE, which secured disease control and improvement of quality of life in both. Similar to other well-differentiated NETs, SSA and PRRT could constitute efficacious therapeutic options in metastatic middle ear ANEF. Its neuroendocrine differentiation, potential to metastasize and somatostatin receptor type 2 expression prompt consideration and management of this disease as a neuroendocrine neoplasm.

Learning points

• Our cases oppose the 2017 WHO classification of middle ear adenoma with neuroendocrine features as a benign disease.

• This entity warrants long-term follow-up, as local recurrence or persistence of disease is reported in up to 18% of surgically treated patients.

• PET/CT scan with ⁶⁸Ga-labelled somatostatin analogues (SSA) can be used for staging of metastatic middle ear adenoma with neuroendocrine features.

• Unlabelled SSA and peptide receptor radionuclide therapy (PRRT) with radiolabelled SSA can be the first systemic therapeutic options for patients with advanced middle ear adenoma with neuroendocrine features.

Summary

A 34-year-old woman presented 18 months post-partum with blurred vision, polyuria, amenorrhoea, headache and general malaise. Comprehensive clinical examination showed left superior temporal visual loss only. Initial investigations revealed panhypopituitarism and MRI demonstrated a sellar mass involving the infundibulum and hypothalamus. Lymphocytic hypophysitis was suspected and high dose glucocorticoids were commenced along with desmopressin and thyroxine. However, her vision rapidly deteriorated. At surgical biopsy, an irresectable grey amorphous mass involving the optic chiasm was identified. Histopathology was initially reported as granulomatous hypophysitis. Despite the ongoing treatment with glucocorticoids, her vision worsened to light detection only. Histopathological review revised the diagnosis to partially treated lymphoma. A PET scan demonstrated avid uptake in the pituitary gland in addition to splenic involvement, lymphadenopathy above and below the diaphragm, and a bone lesion. Excisional node biopsy of an impalpable infraclavicular lymph node confirmed nodular lymphocyte-predominant Hodgkin lymphoma. Hyper-CVAD chemotherapy was commenced, along with rituximab; fluid-balance management during chemotherapy (with its requisite large fluid volumes) was extremely complex given her diabetes insipidus. The patient is now in clinical remission. Panhypopituitarism persists; however, her vision has recovered sufficiently for reading large print and driving. To the best of our knowledge, this is the first reported case of Hodgkin lymphoma presenting initially as hypopituitarism.

Learning points

• Lymphoma involving the pituitary is exceedingly rare and, to the best of our knowledge, this is the first reported case of nodular lymphocyte-predominant Hodgkin lymphoma presenting as hypopituitarism.

• There are myriad causes of a sellar mass and this case highlights the importance of reconsidering the diagnosis when patients fail to respond as expected to appropriate therapeutic intervention.

• This case highlights the difficulties associated with managing panhypopituitary patients receiving chemotherapy, particularly when this involves large volumes of i.v. hydration fluid.

Summary

Lamin A/C (LMNA) gene mutations cause a heterogeneous group of progeroid disorders, including Hutchinson–Gilford progeria syndrome, mandibuloacral dysplasia, atypical progeroid syndrome (APS) and generalized lipodystrophy-associated progeroid syndrome (GLPS). All of those syndromes are associated with some progeroid features, lipodystrophy and metabolic complications but vary differently depending on a particular mutation and even patients carrying the same gene variant are known to have clinical heterogeneity. We report a new 30-year-old female patient from Russia with an APS and generalized lipodystrophy (GL) due to the heterozygous de novo LMNA p.E262K mutation and compare her clinical and metabolic features to those of other described patients with APS. Despite many health issues, short stature, skeletal problems, GL and late diagnosis of APS, our patient seems to be relatively metabolically healthy for her age when compared to previously described patients with APS.

Learning points

• Atypical progeroid syndromes (APS) are rare and heterogenic with different age of onset and degree of metabolic disorders, which makes this diagnosis very challenging for clinicians and may be missed until the adulthood.

• The clinical picture of the APS depends on a particular mutation in the LMNA gene, but may vary even between the patients with the same mutation.

• The APS due to a heterozygous LMNA p.E262K mutation, which we report in this patient, seems to have association with the generalized lipodystrophy, short stature and osteoporosis, but otherwise, it seems to cause relatively mild metabolic complications by the age of 30.

• The patients with APS and lipodystrophy syndromes require a personalized and multidisciplinary approach, and so they should be referred to highly specialized reference-centres for diagnostics and treatment as early as possible.

• Because of the high heterogeneity of such a rare disease as APS, every patient’s description is noteworthy for a better understanding of this challenging syndrome, including the analysis of genotype-phenotype correlations.

Summary

A 38-year-old female was identified as carrying a heterozygous pathogenic MEN1 variant (c.1304delG) through predictive genetic testing, following a diagnosis of familial hyperparathyroidism. Routine screening for parathyroid and pituitary disease was negative. However, cross-sectional imaging by CT revealed a 41 mm pancreatic tail mass. Biopsy via endoscopic ultrasound confirmed the lesion to be a well-differentiated (grade 1) pancreatic neuroendocrine tumour (pNET) with MIB1<1%. Biochemically, hyperinsulinaemic hypoglycaemia was confirmed following an overnight fast, which was subsequently managed by diet alone prior to definitive surgery. Pre-operative work-up with octreotide SPECT CT demonstrated avid tracer uptake in the pancreatic lesion and, unexpectedly, a focal area of uptake in the left breast. Further investigation, and subsequent mastectomy, confirmed ductal carcinoma in situ pT2 (23 mm) grade 1, N0 (ER positive; HER2 negative). Following mastectomy, our patient underwent a successful distal pancreatectomy to resect the pNET. Loss of heterozygosity (LOH) at the MEN1 locus was found in both the breast tumour and pNET, thereby in keeping with a 'two-hit' hypothesis of oncogenesis, a suggestive but non-definitive clue for causation. To obtain further support for a causative relationship between MEN1 and breast cancer, we undertook a detailed review of the published literature which overall supports the notion that breast cancer is a MEN1-related malignancy that presents at a younger age and histologically, is typically of ductal subtype. Currently, clinical guidance regarding breast cancer surveillance in MEN1 does not exist and further research is required to establish a clinical and cost-effective surveillance strategy).

Learning points

• We describe a case of pNET and breast cancer diagnosed at a young age of 38 years in a patient who is heterozygous for a pathogenic MEN1 variant. Loss of the wild-type allele was seen in both breast tissue and pNET specimen.

• Breast cancer may be an under-recognised MEN1-associated malignancy that presents at a younger age than in the general population with a relative risk of 2–3.

• Further research is required to determine the cost-effectiveness of breast cancer surveillance approach at a younger age in MEN1 patients relative to the general population .

Summary

Gynecomastia is a symptom with a potential high disease burden. It has a variety of underlying causes, such as malignant, drug-related or hormonal. The presence of gynecomastia can be explained in thyrotoxicosis due to a concomitant disbalance of sex hormones. Interestingly, it rarely is the presenting symptom of Graves’ disease. A 49-year-old man presented to our outpatient clinic with right-sided gynecomastia. After thorough history taking, more symptoms of thyrotoxicosis were present. Treatment was started with thiamazole and later levothyroxine. Three months after this treatment the gynecomastia and other symptoms resolved completely. A disbalance of sex hormones due to an increased expression of the protein sex hormone-binding globulin (SHBG) caused by thyrotoxicosis could result in gynecomastia. In vitro and in vivo research in mice suggest that the pathophysiology of thyrotoxicosis-associated gynecomastia is due to upregulation of hepatocyte nuclear factor-4α (HNF4A) in liver cells. Subsequent increase of SHBG results in a decrease of free testosterone levels.

Learning points

• Gynecomastia is a common finding (up to almost 40%) on physical examination in patients with hyperthyroidism.

• In gynecomastia, thyroid function tests should be examined on initial presentation because of the relative simple treatment.

• The pathophysiology of thyrotoxicosis-associated gynecomastia is well understood by a sex-hormonal disbalance due to an increased expression of SHBG.

• Due to the well explainable pathophysiology, reduction of symptoms can be expected after treatment.

• The underlying mechanism of an increased expression of SHBG is not well understood. However, in vitro and in vivo research in mice suggests that thyrotoxicosis causes an increased expression of HNF4A in liver cells. Thus, upregulating the expression of SHBG.

• Interestingly, HNF4A is suspected to play an important role in MODY. Future research will clarify the importance of this gene and might open up new insights for therapy.

Summary

A 41-year-old male presented to the Emergency Department with a 6-month history of back and hip pain. Skeletal survey revealed bilateral pubic rami fractures and MRI of the spine demonstrated multiple thoracic and lumbar fractures. Secondary work up for osteoporosis was undertaken. There was no evidence of hyperparathyroidism and the patient was vitamin D replete. Testosterone (T) was low at 1.7 nmol/L (8.6–29.0) and gonadotrophins were undetectable. The patient failed a 1 mg dexamethasone suppression test (DST) with a morning cortisol of 570 nmol/L (<50) and subsequently a low dose DST with a cortisol post 48 h of dexamethasone of 773 nmol/L (<50) and an elevated ACTH 98 ng/L. A corticotropin-releasing factor (CRF) test suggested ectopic ACTH secretion. The patient was commenced on teriparatide for osteoporosis and metyrapone to control the hypercortisolaemia. A positron emission tomography (PET) scan to look for the source of ACTH secretion demonstrated right neck adenopathy. Biopsy and subsequent lymph node dissection were performed and histology revealed a metastatic neuroendocrine tumour. Immunostaining was positive for calcitonin and thyroid transcription factor 1 (TTF1). Serum calcitonin was also significantly elevated at 45 264 ng/L (<10). The patient proceeded to a total thyroidectomy and left neck dissection. Histology confirmed a 7 mm medullary thyroid carcinoma (MTC). Post-operatively, the patient commenced vandetanib therapy and achieved a clinical and biochemical response. After approximately 18 months of vandetanib therapy, the patient developed recurrent disease in his neck. He is currently on LOXO-292 and is doing well 36 months post-diagnosis.

Learning points

• Unexplained osteoporosis requires thorough investigation and the workup for secondary causes is not complete without excluding glucocorticoid excess.

• MTC should be considered when searching for sources of ectopic ACTH secretion.

• Resistance to tyrosine kinase inhibitors is well described with MTC and clinicians should have a low threshold for screening for recurrent disease.

Summary

A phaeochromocytoma is a rare neuroendocrine tumour derived from the chromaffin cells of the adrenal medulla. Tumours can produce excessive amounts of catecholamines. The presenting symptoms can vary but often include the classic triad of episodic headaches, sweating and palpitations. Due to catecholamine excess, patients can develop cardiomyopathy. Bradycardia and collapse could be the result of sinus node dysfunction or transient dysregulation of the autonomic nervous system. Patients with co-existing diabetes can have improvement or resolution of their diabetes after successful adrenalectomy. We report a case of an 87-year-old lady who initially presented with sweating, palpitations and collapse, resulting in a permanent pacemaker insertion. She was later found to have a large adrenal incidentaloma with subsequent markedly elevated plasma metanephrine levels. She later presented with chest pain and in acute pulmonary oedema with normal coronary arteries visualised on coronary angiogram. After surgical excision of her phaeochromocytoma, her diabetes resolved with her HbA1c improving from 68 to 46 mmol/mol, with no further requirement for diabetic medications. Her pulmonary oedema improved with no ongoing need for diuretic therapy. This case highlights that phaeochromocytomas can affect multiple systems and there should be a very high index of suspicion in patients presenting with sweating, palpitations, hypertension and a history of diabetes and even in those with collapse.

Learning points

• There should be a high index of suspicion for phaeochromocytomas in patients with palpitations, diaphoresis, anxiety, hypertension and diabetes.

• Rarely phaeochromocytomas can present as bradycardia and collapse due to sinus node dysfunction or transient autonomic dysregulation and that should be considered in older patients.

• Catecholamine cardiomyopathy can occur in phaeochromocytoma with potential resolution after successful surgical excision.

• Diabetes can resolve after successful surgical treatment of a phaeochromocytoma.