Summary

A patient treated with intramuscular testosterone replacement therapy for primary hypogonadism developed blurred vision shortly after receiving his testosterone injection. The symptom resolved over subsequent weeks and recurred after his next injection. A diagnosis of central serous chorioretinopathy (CSR) was confirmed following ophthalmology review. A decision was made to change the patient’s testosterone regime from this 12-weekly intramuscular injection to a daily topical testosterone gel, given the possibility that peak blood levels of testosterone following intramuscular injection were causing his ocular complaint. His CSR did not recur after this change in treatment. CSR secondary to testosterone therapy is a rare finding but has been reported previously in the literature.

Learning Points

• Blurred vision in patients treated with testosterone replacement therapy (TRT) should prompt an ophthalmology review.

• The potential for reduced risk of central serous chorioretinopathy (CSR) with daily transdermal testosterone remains a matter of conjecture.

• CSR is a rare potential side effect of TRT.

Summary

Insulinomas are rare pancreatic neuroendocrine neoplasms (NENs) that are typically sporadic and solitary, with the majority being <2 cm in diameter at diagnosis. The median duration of symptoms before diagnosis is variable; however, this is usually in the region of 12–18 months. We report on an insulinoma diagnosed some 25 years following initial symptoms, having by that stage attained a diameter of 4 cm. We present a 50-year-old man who was reported with hypoglycaemic symptoms on his wedding 25 years prior to eventual confirmation of an insulinoma. He had since learned to live with the symptoms by eating frequently to manage his hypoglycaemia. However, over recent months, he reported a substantial deterioration in his symptoms, and indeed, had collapsed on two occasions. He had a fasting glucose of 2.9 mmol/L with grossly inappropriate elevated insulin and C-peptide levels. MRI demonstrated a 4.1 cm lesion at the body of pancreas and an indeterminate 9-mm liver lesion with a negative ⁶⁸Gallium-DOTATATE PET scan. Accordingly, he was initiated on diazoxide and referred to the surgical team for distal pancreatectomy: histology confirmed a 4.4-cm well-differentiated pancreatic NEN of intermediate grade (NEN G2, Grade 2, 2017 World Health Organization (WHO) pancreatic-NEN classification), with positive immunohistochemistry for insulin. His hypoglycaemia episodes have ceased, and he remains under active surveillance. Our case demonstrates the possibility of dietary control of insulinoma-induced hypoglycaemia, and the likelihood that such a prolonged delay in diagnosis has led to the uncommonly large size of the apparently benign tumour which is usually ‘small and indolent’.

Learning points

• Most patients with insulinomas have lesions that are 1–2 cm in size, with 96% being less than 3 cm.

• The mean tumour size of insulinomas found in 3 of the largest reported series was 1.5 cm, with a range of 0.1–7.0 cm.

• It is not uncommon for patients to have symptoms for several months to years before diagnosis; however, no reported cases had the symptoms such long for 25 years, and the large size of the tumour in this case may reflect the very long history.

Summary

Vasoactive intestinal peptide-secreting tumours (VIPomas) are an extremely rare form of functional pancreatic neuroendocrine tumour with an estimated annual incidence of 1 in 10 million. Associated tumour hypersecretion of other peptides, including pancreatic polypeptide (PPomas), may also be seen. These malignancies classically present with a defined triad of refractory diarrhoea, hypokalaemia and metabolic acidosis known as Verner–Morrison syndrome. Diagnosis is frequently delayed, and the majority of patients will have metastatic disease at presentation. Symptoms are usually well controlled with somatostatin analogue administration. Here we report a case of metastatic mixed VIPoma/PPoma-induced diarrhoea causing renal failure so severe that ultrafiltration was required to recover adequate renal function.

Learning points

• Profuse, watery diarrhoea is a common presenting complaint with a multitude of aetiologies. This, combined with the rarity of these tumours, makes diagnosis difficult and frequently delayed. A functional neuroendocrine tumour should be suspected when diarrhoea is unusually extreme, prolonged and common causes have been promptly excluded.

• These patients are likely to be profoundly unwell on presentation. They are extremely hypovolaemic with dangerous electrolyte and metabolic abnormalities. Aggressive initial rehydration and electrolyte replacement are imperative. A somatostatin analogue should be commenced as soon as the diagnosis is suspected.

• This is an extreme example of Verner–Morrison syndrome. We are unaware of another case where renal failure secondary to diarrhoea and dehydration was so severe that renal replacement therapy was required to restore adequate renal function, further emphasising how critically unwell these patients can be.

• Both the primary tumour and metastases showed a remarkably good and rapid response to somatostatin analogue administration. Cystic change and involution were noted on repeat imaging within days.

• Prior to his illness, this patient was extremely high functioning with no medical history. His diagnosis was an enormous psychological shock, and the consideration and care for his psychological well-being were a crucial part of his overall management. It highlights the importance of a holistic approach to cancer care and the role of the clinical nurse specialist within the cancer multidisciplinary team.

Summary

The coexistence of autoimmune diabetes and maturity-onset diabetes (MODY) is rare. The absence of pancreatic autoantibodies is a key factor prompting MODY genetic testing. In this study, we report three cases of young-onset diabetes with progressive beta-cell dysfunction, strongly positive glutamic acid decarboxylase (GAD) antibodies, and genetic confirmation of pathogenic gene variants of HNF-1A, HNF-4A, and ABCC8-MODY. The first case is a woman diagnosed with HNF-1A-MODY diabetes more than 30 years after her diagnosis of adult-onset diabetes at 25 years. She required insulin after her fourth pregnancy. She became ketotic on oral hypoglycaemic agents (OHAs) and subsequently, her GAD antibodies tested positive. The second case is a woman diagnosed with diabetes at 17 years who was subsequently diagnosed with HNF-4A-MODY after many hypoglycaemic episodes on low-dose insulin. GAD antibodies were strongly positive. The last case is a man diagnosed with diabetes at 26 years who was well controlled on OHAs and required insulin years later due to sudden deterioration in glycaemic control. His ABCC8-MODY was diagnosed upon realisation of strong family history and his GAD antibodies tested positive. All subjects are now treated with insulin. Less than 1% of subjects with MODY have positive autoantibodies. These cases highlight individuals who may have two different types of diabetes simultaneously or consecutively. Deterioration of glycaemic control in subjects with MODY diabetes should highlight the need to look for the emergence of autoantibodies. At each clinic visit, one should update the family history as MODY was diagnosed in each case after the development of diabetes in their offspring.

Learning points

• These cases highlight the rare coexistence of autoimmune diabetes and MODY.

• Deterioration of glycaemic control in subjects with MODY diabetes should highlight the emergence of autoantibodies.

• One should revise and update the family history as the diagnosis of MODY was made after the development of diabetes in offspring.

• Understanding the spectrum of diabetes allows for precision medicine.

Summary

Hyponatraemia is the most common electrolyte disturbance in hospitalised patients and is associated with numerous adverse outcomes. Patients with schizophrenia are particularly susceptible to hyponatraemia, in part due to the close association between this condition and primary polydipsia. We report the case of a 57-year-old woman with schizophrenia and primary polydipsia who was receiving inpatient psychiatric care. She became increasingly confused, had multiple episodes of vomiting, and collapsed 1 week after being commenced on quetiapine 300 mg. On examination, she was hypertensive and her Glasgow coma scale was nine. She had a fixed gaze palsy and a rigid, flexed posture. Investigations revealed extreme hyponatraemia with a serum sodium of 97 mmol/L. A CT brain demonstrated diffused cerebral oedema with sulcal and ventricular effacement. A urine sodium and serum osmolality were consistent with SIAD, which was stimulated by the introduction of quetiapine. The antidiuretic effect of vasopressin limited the kidney’s ability to excrete free water in response to the patients' excessive water intake, resulting in extreme, dilutional hyponatraemia. The patient was treated with two 100 mL boluses of hypertonic 3% saline but deteriorated further and required intubation. She had a complicated ICU course but went on to make a full neurological recovery. This is one of the lowest sodium levels attributed to primary polydipsia or second-generation antipsychotics reported in the literature.

Learning points

• The combination of primary polydipsia and SIAD can lead to a life-threatening, extreme hyponatraemia.

• SIAD is an uncommon side effect of second-generation anti-psychotics.

• Serum sodium should be monitored in patients with primary polydipsia when commencing or adjusting psychotropic medications.

• Symptomatic hyponatraemia is a medical emergency that requires treatment with boluses of hypertonic 3% saline.

• A serum sodium of less than 105 mmol/L is associated with an increased risk of osmotic demyelination syndrome, therefore the correction should not exceed 8 mmol/L over 24 h.

Summary

A 32-year-old Caucasian male presented to the emergency department with a one-day history of acute severe bilateral lower limb weakness, three days after competing in a bodybuilding competition. He consumed large quantities of carbohydrate-rich foods following the competition. His past medical history was significant for anxiety, and family history was non-contributory. Examination was normal except for reduced power and hyporeflexia in both legs, despite his muscular physique. He was noted to have severe hypokalaemia (K⁺= 1.9 mmol/L). His thyroid function tests were consistent with thyrotoxicosis. He reported taking thyroxine and several other agents to facilitate muscle mass generation before the bodybuilding competition. His presentation was reminiscent of thyrotoxic periodic paralysis, albeit uncommon with Caucasian ethnicity. He also had transient hyperglycaemia at presentation with concomitant hyperinsulinaemia, which could be attributed to the carbohydrate load and may have exacerbated his hypokalaemia through a transcellular shift. Urine toxicology screen subsequently ruled out the use of diuretics but confirmed the presence of a long-acting beta agonist (clenbuterol) which, along with other substances, may have aggravated the hypokalaemia further. After 12 h of i.v. replacement, the potassium level normalised and leg weakness resolved. The patient agreed to stop taking thyroxine and beta agonists and was well during the clinic visit at one month follow-up. This case highlights the potential for thyrotoxicosis factitia to exacerbate hypokalaemia and muscle weakness from other causes in bodybuilders presenting with acute severe weakness, irrespective of ethnicity.

Learning points

• In patients presenting with muscle weakness and hypokalaemia, early consideration of thyrotoxicosis is essential, even in the absence of a past history of thyroid disease or specific symptoms of thyrotoxicosis, in order to allow prompt initiation of appropriate treatment and to prevent recurrence.

• Bodybuilders may constitute a uniquely ‘at-risk’ group for thyrotoxic periodic paralysis secondary to thyrotoxicosis factitia, especially where there is concomitant use of beta-adrenergic agonists, even in the absence of diuretic use.

• Although rare and usually described in patients of Asian or Polynesian ethnicity, this case highlights that thyrotoxic periodic paralysis secondary to thyrotoxicosis factitia can also occur in patients with Caucasian ethnicity.

• We speculate that consuming large quantities of carbohydrates may induce hyperinsulinaemia, which could theoretically contribute to worse hypokalaemia, though mechanistic studies would be needed to explore this further.

Summary

Adrenocortical carcinoma (ACC) is a rare malignancy with an incidence of 0.7–2.0 cases/million/year. A majority of patients present with steroid hormone excess or abdominal mass effects, and in 15% of patients ACC is discovered incidentally. We present a case of 30-year-old otherwise asymptomatic Caucasian male who presented with a testicular swelling. Subsequent imaging and investigations revealed disseminated sarcoidosis and an 11 cm adrenal lesion. An adrenalectomy was performed. Histological examination of the resected specimen confirmed an ACC and also demonstrated a thin rim of adrenal tissue containing non-caseating granulomas, consistent with adrenal sarcoid.

Learning points

• This case highlights an unusual presentation of two uncommon diseases.

• This case also highlights how separate and potentially unrelated disease processes may occur concomitantly and the importance, therefore, of keeping an open mind when dealing with unusual diagnostic findings.

• We also hypothesize a potential link between the ACC and sarcoidosis in our patient.

Summary

Phaeochromocytoma is a rare catecholamine-producing tumour. We present the case of phaeochromocytoma in a young man with a background history of a double-lung transplant for cystic fibrosis (CF). Clinical case: A 25-year-old man, with a background history of CF, CF-related diabetes (CFRD) and a double-lung transplant in 2012 was presented to the emergency department with crampy abdominal pain, nausea and vomiting. He was diagnosed with distal intestinal obstructions syndrome (DIOS). Contrast-enhanced CT imaging of the abdomen and pelvis showed a 3.4 cm right adrenal lesion. This was confirmed by a subsequent MRI of adrenal glands that demonstrated moderate FDG uptake, suggestive of a diagnosis of phaeochromocytoma. The patient was noted to be hypertensive with a blood pressure averaging 170/90 mm/Hg despite treatment with three different anti-hypertensive medications – amlodipine, telmisartan and doxazosin. He had hypertension for the last 3 years and had noted increasingly frequent sweating episodes recently, without palpitations or headache. Laboratory analysis showed elevated plasma normetanephrines (NMN) of 3167 pmol/L (182–867) as well as elevated metanephrines (MN) of 793 pmol/L (61–377) and a high 3-MT of 257 pmol/L (<185). Once cathecholamine excess was identified biochemically, we proceeded to functional imaging to further investigate. MIBG scan showed a mild increase in the uptake of tracer to the right adrenal gland compared to the left. The case was discussed at a multidisciplinary (MDT) meeting at which the diagnosis of phaeochromocytoma was made. Following a challenging period of 4 weeks to control the patient’s blood pressure with an alpha-blocker and beta-blocker, the patient had an elective right adrenalectomy, with normalisation of his blood pressure post-surgery. The histopathology of the excised adrenal gland was consistent with a 3 cm phaeochromocytoma with no adverse features associated with malignant potential.

Learning points

• Five to ten per cent of patients have a secondary cause for hypertension. Phaeochromocytomas are rare tumours, originating in chromaffin cells and they represent 0.1–1.0% of all secondary hypertension cases.

• Secondary causes should be investigated in cases where:

• Patient is presenting <20 years of age or >50 years of age,

• There is refractory hypertension, or

• There is serious end-organ damage present.

• Patients may present with the triad of headache, sweating and palpitations or more vague, non-specific symptoms.

• Patients with suspected phaeochromocytoma should have 24-h urinary catecholamines measured and if available, plasma metanephrines measured. Those with abnormal biochemical tests should be further investigated with imaging to locate the tumour.

• Medical treatment involves alpha- and beta-blockade for at least 2 to 3 weeks before surgery as well as rehydration.

• There is a possibility of relapse so high-risk patients require life-long follow-up.

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.

Learning points:

• Infiltrating metastases into pituitary adenomas are very rare but do occur.

• To our knowledge this is the third case of breast adenocarcinoma metastasising to a gonadotroph pituitary adenoma.

• Pituitary metastases should always be considered in rapidly evolving pituitary symptoms in a cancer patient.

• Not all complex pituitary lesions are associated with panhypopituitarism.

• Early invasive local management (TSS and post TSS radiotherapy) can provide rapid satisfactory outcomes.