Summary

Paraneoplastic syndromes (PS) are uncommon and are known to mimic other clinical entities, often carrying significant morbidity and mortality. The commonest cause of extra-ocular muscle enlargement (EOME) is thyroid eye disease (TED). Rarely, PS can cause EOME and masquerade as TED. We describe a 52-year-old female who presented with diarrhoea, acute kidney injury and electrolyte imbalance. An ophthalmic review identified right upper lid retraction. MRI orbits showed increased thickness of the inferior and medial recti bilaterally, presumed as TED. Whilst investigating her diarrhoea, imaging revealed a large rectosigmoid tumour which required surgical excision. In the context of electrolyte disturbance and acute kidney injury, a diagnosis of McKittrick–Wheelock syndrome (MWS) was made. Following successful surgery, electrolyte imbalance, diarrhoea and eyelid retraction improved. Repeat MRI orbits displayed complete resolution of EOME. To our knowledge, this is the first case of MWS presenting with PS-EOME masquerading as TED.

Learning points

• McKittrick–Wheelock syndrome (MWS) is a rare disorder, although likely under-recognised, which is characterised by diarrhoea, dehydration and electrolyte depletion that results from a hypersecretory colorectal neoplasm.

• Definitive treatment of MWS involves the resection of the colorectal neoplasm.

• Bilateral ophthalmopathy that appears to be Graves’ ophthalmopathy on imaging, though clinical and biochemical evidence fails to identify a thyroid pathology, has been associated with malignancy on rare occasions. Such patients should be investigated for potential malignant causes of their ophthalmopathy.

Summary

Pathogenic variants in the nuclear receptor subfamily 5 group A member 1 gene (NR5A1), which encodes steroidogenic factor 1 (SF1), result in 46,XY and 46,XX differences of sex development (DSD). In 46,XY individuals with a pathogenic variant in the NR5A1 gene a variable phenotype ranging from mild to severe is seen, including adrenal failure, testis dysgenesis, androgen synthesis defects, hypospadias and anorchia with microphallus and infertility. We report the clinical, endocrinological and genetic characteristics of a patient with 46,XY DSD with a novel likely pathogenic missense variant in the NR5A1 gene. A retrospective evaluation of the medical history, physical examination, limited endocrinological laboratory analysis and genetic analysis with DSD gene panel testing was performed. A 1.5-month-old individual was referred with ambiguous genitalia. The karyotype was 46,XY. The endocrinological analyses were within normal male reference including a normal response of cortisol within an adrenocorticotropic hormone test. A novel heterozygous missense variant c.206G>C p.(Arg69Pro) in the NR5A1 gene was detected. This variant was present in mosaic form (~20%) in his unaffected father. Because another missense variant at the same position and other missense variants involving the same highly conserved codon have been reported, we consider this NR5A1 variant in this 46,XY DSD patient as likely pathogenic in accordance with the ACMG/AMP 2015 guidelines causing ambiguous genitalia but no adrenal insufficiency. This variant was inherited from the apparently unaffected mosaic father, which might have implications for the recurrence risk in this family.

Learning points

• The importance of performing trio (patient and parents) sequencing is crucial in pointing out the origin of inheritance.

• In a 46,XY differences of sex development patient, a normal adrenal function does not rule out an NR5A1 mutation.

• With the support of a dedicated overseas institute partnership, we could solve this complex clinical case by molecular diagnosis in a resource-limited setting.

Summary

Multiple research studies address the anti-insulinemic effect of growth hormone (GH). We report a case of a patient with anterior hypopituitarism on GH replacement who later developed type 1 diabetes mellitus (T1DM). Recombinant human growth hormone (rhGH) therapy was discontinued at the time of growth completion. Because of significantly improved glycemic control, this patient was weaned off subcutaneous insulin. He regressed from stage 3 to stage 2 T1DM and remained in this status for at least 2 years and until the writing of this paper. The diagnosis of T1DM was established based on relatively low C-peptide and insulin levels for the degree of hyperglycemia as well as seropositivity of zinc transporter antibody and islet antigen-2 antibody. Additional laboratory data obtained 2 months after discontinuing rhGH revealed improved endogenous insulin secretion. This case report calls attention to the diabetogenic effect of GH therapy in the setting of T1DM. It also demonstrates the possibility of regression from stage 3 T1DM requiring insulin therapy to stage 2 T1DM with asymptomatic dysglycemia after discontinuing rhGH.

Learning points

• Given the diabetogenic effect of growth hormone, blood glucose levels should be monitored in patients with type 1 diabetes mellitus (T1DM) on insulin therapy and recombinant human growth hormone (rhGH) replacement.

• Clinicians should closely monitor for risk of hypoglycemia after discontinuing rhGH among T1DM patients who are on insulin treatment.

• The discontinuation of rhGH in the setting of T1DM may cause regression of symptomatic T1DM to asymptomatic dysglycemia requiring no insulin treatment.

Summary

A 59-year-old male presented with an accidental thyroid mass in 2022. Ultrasound and CT scan showed a nodule 5.2 × 4.9 × 2.8 cm (EU-TIRADS 4) in the right lobe of the thyroid gland. Taking into account the results of the fine needle aspiration biopsy (Bethesda V), intrathyroid localization, and absence of clinical symptoms, a malignant tumor of the thyroid gland was suspected. The patient underwent total thyroidectomy using fluorescence angiography with indocyanine green, and two pairs of intact parathyroid glands were visualized in typical localization. Unexpected histological and immunohistochemistry examinations revealed parathyroid carcinoma. Due to the asymptomatic course of the disease and atypical localization of parathyroid tumor, primary hyperparathyroidism was not suspected before the surgery. The diagnosis of asymptomatic intrathyroid parathyroid cancer is a serious diagnostic challenge for a wide range of specialists.

Learning points

• Parathyroid cancer is a rare disease that may be asymptomatic.

• Intrathyroidal localization of parathyroid carcinoma is casuistic and challenging for diagnosis, and the treatment strategy is not well defined.

• Preoperative parathyroid hormone and serum calcium testing are recommended for patients with solid thyroid nodules (Bethesda IV–V).

Summary

Acute illness-related stress can result in severe hypercortisolism and bilateral adrenal enlargement in certain patients. We report a case of stress-induced hypercortisolism and bilateral adrenal enlargement in a patient admitted for acute respiratory distress and cardiogenic shock. Bilateral adrenal enlargement and hypercortisolism found during hospitalization for acute illness resolved 3 weeks later following the resolution of acute illness. Acute illness can be a precipitating factor for stress-induced hypercortisolism and bilateral adrenal enlargement. We hypothesize that increased adrenocorticotrophic hormone mediated by corticotrophin-releasing hormone from physical stress resulted in significant adrenal hyperplasia and hypercortisolism. This mechanism is downregulated once acute illness resolves.

Learning points

• Adrenal enlargement with abnormal adrenal function after stress is uncommon in humans; however, if present, it can have self-resolution after the acute illness is resolved.

• Stress induces enlargement of the adrenals, and the degree of cortisol elevation could be very massive. This process is acute, and the absence of cushingoid features is expected.

• Treatment efforts should be focused on treating the underlying condition.

Summary

A 77-year-old female patient with a history of treated breast cancer and a recently diagnosed laryngeal cancer presented with severe hypercalcaemia associated with suppressed parathyroid hormone (PTH) levels. Her initial investigations included 25-hydroxy vitamin D levels, short synacthen test, bone scan, myeloma screen and thyroid function tests which were within normality. A computerised tomography (CT) scan showed some right lung apical fibrotic changes. Her PTH-related peptide (PTHrP) was normal and sarcoidosis was also excluded. Her previous and current malignancies were thought to be unlikely behind her hypercalcaemia. Her 1,25-dihydroxy vitamin D (calcitriol) levels were found to be elevated. Her hypercalcaemia was initially managed with intravenous fluids and intermittent bisphosphonates infusions which would transiently reduce her calcium levels. Steroid treatment was initiated which improved her hypercalcaemia; however, the calcium levels rebounded on tapering the steroids down, a pre-requisite prior to a positron emission computerised tomography (PET-CT) scan to determine the source of the excess calcitriol production. This was cancelled following an emergency admission with marked hypercalcaemia and acute renal and liver injury. A contemporary CT scan showed a right apical lung mass with hepatic lesions suggestive of a disseminated lung primary. The histology obtained from a liver biopsy was compatible with metastatic small-cell lung carcinoma. Unfortunately, her clinical condition deteriorated further and she did not survive. To the best of our knowledge, this is the first report in the literature describing calcitriol-mediated hypercalcaemia due to a small-cell lung cancer.

Learning points

• Paraneoplastic hypercalcaemia may manifest even without overt detection of the primary cancer.

• The workup for paraneoplastic hypercalcaemia should be meticulous.

• Both bisphosphonates and steroids are useful in the initial management of calcitriol-mediated hypercalcaemia, but the definitive management is the treatment of the cause.

Summary

The anatomy of the pituitary fossa is complex. The wall of the fossa can vary, resulting in inconsistencies in the nature and integrity of the sella barrier. Cerebrospinal fluid is generally confined to the subarachnoid space and does not circulate freely in the pituitary fossa. Spontaneous haemorrhage in the fossa typically occurs in the context of pre-existing intrasellar pathology such as a pituitary adenoma. Extravasation of blood into the subarachnoid space can rarely be observed following pituitary apoplexy. We describe the unique occurrence of subarachnoid haemorrhage in a largely empty pituitary fossa after the rupture of a cerebral aneurysm.

Learning points

• Pituitary apoplexy and subarachnoid haemorrhage (SAH) are both high in the differential diagnosis of sudden onset severe headaches.

• Haemorrhagic pituitary apoplexy may result in extravasation into the subarachnoid space, resulting in typical SAH symptoms and signs.

• This is the first reported case of primary SAH resulting in blood pooling in an empty sella arising from previous surgical resection of a large macroadenoma.

Summary

A 64-year-old man with progressive metastatic castrate-resistant prostate adenocarcinoma presented with recurrent fluid overload, severe hypokalaemia with metabolic alkalosis and loss of glycaemic control. Clinical features were facial plethora, skin bruising and proximal myopathy. Plasma adrenocorticotrophic hormone (ACTH), serum cortisol and 24-h urinary cortisol levels were elevated. Low-dose dexamethasone failed to suppress cortisol. Pituitary MRI was normal and ⁶⁸Gallium-DOTATATE PET–CT scan showed only features of metastatic prostate cancer. He was diagnosed with ectopic ACTH syndrome secondary to treatment-related neuroendocrine prostate cancer differentiation. Medical management was limited by clinical deterioration, accessibility of medications and cancer progression. Ketoconazole and cabergoline were utilised, but cortisol remained uncontrolled. He succumbed 5 months following diagnosis. Treatment-related neuroendocrine differentiation of prostate adenocarcinoma is a rare cause of ectopic ACTH syndrome.

Learning points

• Neuroendocrine differentiation following prostate adenocarcinoma treatment with androgen deprivation has been described.

• Ectopic adrenocorticotrophic hormone (ACTH) syndrome should be considered where patients with metastatic prostate cancer develop acute electrolyte disturbance or fluid overload.

• Ketoconazole interferes with adrenal and gonadal steroidogenesis and can be used in ectopic ACTH syndrome, but the impact may be insufficient. Inhibition of gonadal steroidogenesis is favourable in prostate cancer.

• More data are required to evaluate the use of cabergoline in ectopic ACTH syndrome.

• Ectopic ACTH syndrome requires prompt management and is challenging in the face of metastatic cancer.

Summary

Iron metabolism and markers hereof are altered in anorexia nervosa (AN) but far from completely understood. We report a case of extreme hyperferritinemia in a patient with AN and discuss the possible mechanisms and current knowledge about the association between hyperferritinemia and AN. A 20-year-old woman with a history of AN presented with bradycardia, weariness, and malaise in addition to an incidentally very high ferritin level. The symptoms disappeared spontaneously after a short admission. There were no signs suggestive of systemic, hematological, or malignant disease causing the very high concentration of ferritin. Her body weight was in decline, leading up to admission, but did initially increase after discharge accompanied by declining ferritin concentration. However, a clear association between ferritin dynamics and weight changes or physical activity was not identified and neither were other causes of the hyperferritinemia. Around one in four patients with AN have increased ferritin concentrations. Our case represents the highest ferritin concentration reported in a patient with AN without other underlying causes or comorbidities.

Learning points

• Perturbed iron metabolism is frequent in restrictive type anorexia nervosa but incompletely understood.

• Altered ferritin in anorexia nervosa may be linked to nutritional status.

Summary

A 47-year-old man was diagnosed with a left adrenal incidentaloma at 40 years of age. The tumor had irregular margins and grew from 18 mm to 30 mm in maximum diameter over 7 years. On computed tomography scan, the mass appeared to localize within the tip of the lateral limb of the left adrenal gland, and between the left adrenal gland and the posterior wall of the stomach. The plasma corticotropin and cortisol concentrations and the 24-h urine fractionated metanephrine levels were normal. ¹²³I-metaiodobenzylguanidine scintigraphy showed tumor avidity consistent with a hormonally inactive pheochromocytoma. A laparoscopic left adrenalectomy was performed; however, no tumor was present in the resected specimen. Abdominal computed tomography postoperatively showed that the tumor remained intact and appeared to connect to the posterior wall of the stomach. A laparotomy was performed and the tumor was removed. The tumor was localized to the intraperitoneal space and isolated from the posterior wall of the stomach. The pathological diagnosis was a gastrointestinal stromal tumor. Clinicians need to be aware of the limitations of diagnostic imaging studies in diagnosing non-functioning adrenal incidentalomas, which require a pathological analysis for the final diagnosis. Moreover, clinicians need to provide patients with sufficient informed consent when deciding on treatment strategies.

Learning points

• Anatomic structures and tumors that develop in neighboring tissues to the adrenal glands may be confused with primary adrenal tumors.

• ¹²³I- metaiodobenzylguanidine (MIBG) scintigraphy is specific for diagnosing pheochromocytomas and paragangliomas; however, it has been reported that ¹²³I-MIBG may accumulate in neuroendocrine tumors as well as other tumors.

• Clinicians should recognize the limitations of imaging studies and the uncertainty of an imaging-based preoperative diagnosis.