Summary

A 52-year-old female patient with breast cancer presented with a history of fatigue and malaise 1 year prior. She was diagnosed with isolated adrenocorticotropic hormone (ACTH) deficiency (IAD) on endocrinological examination. Her pituitary gland showed normal morphology. Paraneoplastic IAD associated with breast cancer was suspected; however, immunofluorescence staining revealed no ectopic ACTH or proopiomelanocortin expression in the tumor tissue. Subsequently, the patient was diagnosed with idiopathic acquired IAD concurrent with breast cancer, ruling out paraneoplastic syndrome. Although malignancy should be considered a potential cause of IAD, not all patients with concurrent IAD and malignancy necessarily develop paraneoplastic syndrome.

Learning points

• Several adrenal insufficiency symptoms are similar to the nonspecific symptoms associated with malignancies, and therefore, the diagnosis of IAD remains challenging, especially in patients with cancer.

• When we encounter a case of IAD accompanied by a malignant tumor, it is important to suspect that paraneoplastic IAD, a novel clinical condition as secondary hypophysitis, may be the etiologic agent.

• Although malignant tumours should be considered a potential cause of IAD, not all patients with concurrent IAD and malignancy necessarily develop paraneoplastic autoimmune hypophysitis.

Summary

ACTH-secreting pituitary adenomas causing Cushing’s disease (CD) typically present with weight gain, whereas weight loss and hypokalemia in endogenous Cushing’s patients are suggestive of ectopic ACTH production. We report a case of CD presenting with atypical features of marked weight loss and hypokalemia. A 75-year-old female was admitted to the hospital with a history of profound weight loss, associated with uncontrolled hypertension, hyperglycemia, severe proximal muscle weakness, and hypokalemia. Subsequent investigations, including 24-h urinary free cortisol, 48-h low-dose dexamethasone suppression test, MRI of the sella, and bilateral inferior petrosal sinus sampling, confirmed CD without any evidence of ectopic ACTH production. She became eucortisolemic with medical therapy of ketoconazole and cabergoline, subsequently regained her weight, and became normokalemic. This case illustrates that patients with CD may present with symptoms and biochemical findings that would otherwise suggest ectopic ACTH production.

Learning points

• Patients with CD do not always present with classical clinical features and may present with symptoms and biochemical findings that would otherwise suggest ectopic ACTH production.

• While most patients with CD typically lose weight after biochemical remission, some patients gain weight after the normalization of cortisol levels.

• This case highlights the need to entertain a broad differential in patients presenting with hypokalemia and weight loss and the need to exclude hypercortisolemia.

Summary

Brain metastases as the first clinical presentation of a papillary thyroid carcinoma (PTC) are exceptional, while cavernous angiomas are common cerebral malformations. We report the case of a 36-year-old male with an incidental brain lesion mimicking a cavernous angioma on MRI. Gamma knife radiosurgery was performed, but after 6 months, the patient developed neurological symptoms, and a repeat brain MRI revealed a significant increase in the mass. The patient underwent neurosurgery, and the histological examination of the lesion revealed metastatic carcinoma of thyroid origin. PET–CT and neck ultrasound, subsequently performed, were concordant for the presence of a right lobe nodule and ipsilateral lymph nodes, both with ultrasound features suspicious of malignancy. Total thyroidectomy with central and right lateral neck dissection was performed, and histology confirmed an intrathyroidal multifocal PTC with lymph node metastases. Postoperative radioiodine was administered, and focal uptake within the thyroid bed, without distant metastases or brain remnants, was found on the post-therapeutic whole-body scan. At 2 years from diagnosis, the patient is in good health and undergoes clinical and imaging follow-up.

Learning points

• Brain cavernous angiomas are common cerebral vascular malformations that are usually diagnosed by MRI.

• Despite the high accuracy of MRI, the exam is not pathognomonic, and misdiagnosis cannot be excluded.

• Brain metastases from PTC are very rare; however, they can mimic a cavernous angioma. Therefore, the differential diagnosis should always be considered.

Summary

Multiple endocrine neoplasia type 1 (MEN1) requires a high level of suspicion, and late diagnosis can lead to dire outcomes. Genetic counselling is an important part of management, with a lack of evidence surrounding an optimal approach in Aboriginal Australian populations. Our case surrounds a remote-dwelling 48-year-old Aboriginal Australian female who was reviewed by an inpatient endocrine team in 2020 for persistent hypercalcaemia on a background of a parathyroidectomy in 2011 for primary hyperparathyroidism (PHPT), while she was admitted to a local hospital for acute chronic abdominal pain. Relevant medical history included multiple pulmonary embolisms/deep vein thrombosis, myocardial infarction, atrial fibrillation, chronic thromboembolic pulmonary hypertension, right heart failure, human T-lymphotropic virus 1, recurrent abdominal pain, and gastro-oesophageal reflux disorder. Gastroscopies from 2013 and 2015 demonstrated chronic gastritis with hundreds of gastric polyps. Subsequent laboratory studies, neuroendocrine tumour (NET) screening, and CT imaging demonstrated a recurrence of PHPT and a new diagnosis of Zollinger–Ellison syndrome. A 68-gallium-DOTATATE PET/CT was in keeping with metastatic NET. Pituitary studies were normal. Genetic testing confirmed a rare heterozygous variant of c.207dupC in exon 2 of the MEN1 gene. Treatment was symptom based due to terminal comorbidities. Genetic counselling was attempted; however, cultural and logistical barriers were identified and the family declined further testing. Unfortunately, she died in 2021 from multifactorial respiratory failure. This case highlights the need for better approaches to genetic counselling systems for remote Aboriginal Australians and emphasizes the importance of early recognition and the challenges faced in remote areas in making such rare diagnoses.

Learning points

• Remote healthcare systems often lack access to adequate specialist care, resulting in delayed diagnosis of rare conditions and leading to morbidity and mortality.

• Further research and work need to be done to provide culturally appropriate genetic counselling systems in remote Aboriginal Australians.

• A high index of suspicion is required to diagnose MEN1.

• Consider MEN1 in any patient diagnosed with primary hyperparathyroidism, with age <40, and/or with the presence of multiglandular disease or with the presence of Zollinger–Ellison syndrome.

• MEN1 may be under-recognized in Aboriginal Australians.

Summary

Congenital adrenal hyperplasia (CAH) is one of the most common inherited rare endocrine disorders. This case report presents two female siblings with delayed diagnosis of non-classical CAH 3β-hydroxysteroid dehydrogenase type 2 (3βHSD2D/HSD3B2) despite early hospital admission and apparent CAH manifestations such as infections, hirsutism, menstrual disturbances, and PCOS phenotype. Initially, sister 1 was misdiagnosed with PCOS and then 11-hydroxylase deficiency (CYP11B1), based on ultrasound, biochemical findings, and negative genetic testing for 21-hydroxylase deficiency (CYP21A2). Additional diagnostic workup was performed when sister 2also presented with symptoms of androgen excess. Genetic testing for CAH/steroid disorders finally revealed that both siblings were compound heterozygous for two variants in the HSD3B2 gene: a frameshift variant, c.558dup, p.(Thr187Hisfs*17) and a novel missense variant, c.65T>C, p.(Leu22Ser). A Synacthen test showed an insufficient cortisol increase. In vitro studies of the variants in a cell model revealed loss of function for the p.(Thr187Hisfs*17) and partial activity for p.(Leu22Ser) confirming non-classic CAH. Overlapping symptomatology and lack of specialized knowledge on steroid biosynthesis and associated rarest forms of CAH may explain the delayed diagnosis. However, with newer diagnostic methods comprising a less biased approach, very rare forms of non-classical CAH may no longer be overlooked in the future.

Learning points

• Non-classic 3βHSD2 is likely underdiagnosed.

• Late diagnosis of mild non-classic 3βHSD2 does occur and one should be aware of this diagnosis.

• Early diagnosis of NCCAH may prevent many consequences such as severe hirsutism, prolonged menstrual irregularities, infertility, or even adrenal crisis with severe infections.

• Comprehensive steroid profiling and genetic testing should be used earlier, especially when in doubt about a diagnosis.

Summary

Multiple endocrine neoplasia type 2 (MEN2) is a hereditary cancer syndrome caused by germline-activating pathogenic variants in the RET proto-oncogene. MEN2A is the most common subtype, with a risk for medullary thyroid cancer (MTC), pheochromocytoma (PHEO), and primary hyperparathyroidism (PHPT), whereas MEN2B is less common and associated with MTC and PHEO along with mucosal neuromas. Little is known about the specific RET germline heterozygous variant K666N. This variant has been described in very few families, and in most cases, patients were diagnosed with a very indolent MTC as the only feature. There is one case of MTC and bilateral PHEO. The RET K666N variant is not stratified yet by the American Thyroid Association, and data are limited on pathogenicity; therefore, appropriate screening and treatment of asymptomatic RET K666N carriers are unclear. Here, we report a family with a heterozygous germline RET K666N variant. The proband was identified when she experienced cardiogenic shock and multi-organ failure after an elective hysterectomy and subsequently was found to have PHEO, with genetic testing revealing the RET K666N germline variant. Patient consent was obtained through IRB protocol COMIRB #15-0516.

Learning Points

• The specific RET germline heterozygous variant K666N is rare and described in very few families, and in most cases, patients were diagnosed with a very indolent MTC as the only feature. Our proband is much younger and has PHEO, MTC, and PHPT.

• The RET K666N germline variant appears to be a low penetrance variant for MEN2.

Summary

An 82-year-old woman with a 60-year history of a lung tumor presented with hypoglycemia. Non-islet cell tumor hypoglycemia (NICTH) was suspected; however, her hypoglycemia stabilized with supplemental food. She was discharged, based on her wishes, and planned to undergo surgery later. After discharge, the hypoglycemia worsened rapidly and required immediate resection. Postoperatively, the hypoglycemia resolved. Western immunoblot analysis confirmed the presence of big insulin-like growth factor 2, confirming NICTH. This patient experienced the rapid progression of symptoms after an unprecedentedly long-term asymptomatic state. Therefore, when NICTH is suspected, early intervention is recommended regardless of the presence of asymptomatic state.

Learning points

• In patients with NICTH, the onset of hypoglycemia is usually within a year of tumor detection, and few reports regarding long-term asymptomatic NICTH have been documented.

• NICTH can cause rapidly progressive symptoms after a long-term asymptomatic state, as in this case, and an asymptomatic state does not preclude the necessity for intervention, especially when patients are at risk for malnutrition.

• Tumor resection is the only curative treatment for patients with NICTH, but there is no consensus regarding the timing of surgery. However, considering the possibility of rapid symptom progression, patients should be examined and treated in a timely manner.

Summary

Familial renal glucosuria (FRG) is a rare renal tubular disorder characterized by increased urinary glucose excretion despite normoglycemia. It is most commonly caused by pathogenic variants in the solute carrier family V member 2 (SLC5A2) gene. This gene encodes the sodium–glucose cotransporter 2, crucial for glucose reabsorption. We report the case of a 44-year-old male referred to the endocrinology outpatient clinic for unexplained glucosuria despite well-controlled diabetes mellitus with metformin and gliclazide therapy. His main complaints were nocturia and an unintentional 5 kg weight loss in 1 year. A 24-h urinary collection revealed overt glucosuria (23.3 g/1.73 m²/24 h), generalized aminoaciduria, and increased uric acid excretion (fractional excretion: 6.4%). Whole-exome sequencing revealed a novel heterozygous c.469-1G>A likely pathogenic variant in the SLC5A2 gene. Specific analysis of the maturity-onset diabetes of the young type (MODY) gene panel showed no pathogenic variants in the hepatocyte nuclear factor-1A (HNF-1A; MODY3) nor in other MODY-associated genes. We assume that the association of glucosuria, aminoaciduria, and increased uric acid excretion can be explained by the combination of diabetes and the likely pathogenic SLC5A2 variant in this patient. In conclusion, we describe a well-controlled diabetic patient with FRG, associated with a novel heterozygous c.469-1G>A likely pathogenic variant in the SLC5A2 gene.

Learning points

• The diagnosis of a renal tubular disorder should be considered in patients with unexplained glucosuria and diabetes mellitus, especially if the latter is well controlled.

• FRG usually presents with glucosuria but may be associated with generalized aminoaciduria and hyperuricosuria.

• Genetic analysis should be considered in patients with young-onset diabetes and glucosuria, particularly with a positive family history.

Summary

Bariatric surgery is increasingly being accepted as a viable treatment for managing the growing obesity epidemic. Roux-en-Y gastric bypass (RYGB) is one of the most commonly performed procedures. Perforated duodenal ulcer following RYGB is a rare condition with a low incidence. We report a case of a patient with a perforated duodenal ulcer post RYGB, and the surgical approach. A 66-year-old man with hypertension and a history of laparoscopic RYGB for class III obesity was admitted to the emergency department with severe epigastric pain radiating to the right side of his abdomen and right shoulder, associated with nausea and vomiting. Computed tomography (CT) showed intraperitoneal free fluid, a thickened wall of the duodenum and free air, duodenal perforation was suspected. The patient underwent exploratory laparoscopy that revealed a perforated duodenal ulcer that was closed with an absorbable barbed suture and omental patch. Perforated ulcers in excluded segments after RYGB are a rare entity with a challenging diagnosis, and clinicians should be aware of and have a low threshold for diagnostic laparoscopy.

Learning points

• Roux-en-Y gastric bypass (RYGB) is one of the most commonly performed procedures in bariatric surgery.

• Perforated ulcers in excluded segments after RYGB are a rare entity with a challenging diagnosis.

• The pathophysiology of this perforation is not clear, but several mechanisms have been proposed. Helicobacter pylori has been implicated.

• Clinicians should be aware and have a low threshold for diagnostic laparoscopy for a patient who has acute abdominal pain after RYGB, despite negative diagnostic measures.

Summary

Hypoglycemia is one of the paraneoplastic syndrome manifestations that arise from primary and secondary liver cancer. Hypoglycemia usually presents in the late stage of the disease and indicates a poor prognosis. This case series displays the characteristics profile of patients with primary and secondary liver cancer who are presented with hypoglycemia in a tertiary referral hospital in Indonesia. The study included 41 liver cancer patients who were presented with hypoglycemia. Hepatocellular carcinoma was diagnosed in 51.2% of patients, metastatic liver disease in 14.6% of patients, and undiagnosed liver cancer in 34.1% of patients. The mean age was 47.7 years with male predominance (65.9%). Jaundice was found in 58.5% and hepatomegaly in 70.7% of patients. The mean (± S.D.) initial blood glucose was 42.15 ± 17.11 mg/dL and the Child–Pugh score was 9.93 ± 2.11. Based on imaging, tumor diameter was 12.6 ± 6.9 cm, multiple (61%), and involving both lobes (61%). Treatments for hypoglycemia included oral/enteral feeding, intravenous dextrose, and steroids. No treatment was given for the cancer because all patients were in an advanced stage. The treatment resulted in 41.5% blood glucose being controlled, 56.1% refractory, and 2.4% persistent. Mortality was 70.7% and in average occurred 5.76 ± 4.99 days after hypoglycemia. The mainstay of treatment in these cases is treating the tumor with cytoreduction. However, it was difficult to do cytoreduction because the tumor was already in an advanced stage. Beneficial supportive treatments for maintaining normal blood glucose are frequent meals, dextrose infusion, steroids, and glucagon.

Learning points

• Hypoglycemia in liver cancer occurs due to the failure of the liver to fulfill body glucose demand because the liver parenchyma has been largely replaced by the tumor, in addition to the high production of insulin growth factor (IGF).

• Hypoglycemia is often caused by islet cell and non-islet cell tumors, with a higher occurrence in non-islet cell tumors due to paraneoplastic syndrome and the high metabolic requirements of the tumor.

• The mainstay of NICTH treatment is treating the tumor with cytoreduction. However, in an advanced stage, cytoreduction therapy is often challenging to conduct. Beneficial supportive treatments for controlling blood glucose are frequent meals, dextrose infusion, and the injection of steroids and glucagon.

• Steroids play a beneficial role in the treatment of persistent hypoglycemia in hepatocellular carcinoma by stimulating gluconeogenesis and increasing lipolysis. Steroids also have roles in the inhibition of peripheral glucose intake, suppression of big IGF-2 production, and modulation of the GH–IGF axis.