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Open access

Gemma White, Nicola Tufton and Scott A Akker

Summary

At least 40% of phaeochromocytomas and paraganglioma’s (PPGLs) are associated with an underlying genetic mutation. The understanding of the genetic landscape of these tumours has rapidly evolved, with 18 associated genes now identified. Among these, mutations in the subunits of succinate dehydrogenase complex (SDH) are the most common, causing around half of familial PPGL cases. Occurrence of PPGLs in carriers of SDHB, SDHC and SDHD subunit mutations has been long reported, but it is only recently that variants in the SDHA subunit have been linked to PPGL formation. Previously documented cases have, to our knowledge, only been found in isolated cases where pathogenic SDHA variants were identified retrospectively. We report the case of an asymptomatic suspected carotid body tumour found during surveillance screening in a 72-year-old female who is a known carrier of a germline SDHA pathogenic variant. To our knowledge, this is the first screen that detected PPGL found in a previously identified SDHA pathogenic variant carrier, during surveillance imaging. This finding supports the use of cascade genetic testing and surveillance screening in all carriers of a pathogenic SDHA variant.

Learning points:

  • SDH mutations are important causes of PPGL disease.

  • SDHA is much rarer compared to SDHB and SDHD mutations.

  • Pathogenicity and penetrance are yet to be fully determined in cases of SDHA-related PPGL.

  • Surveillance screening should be used for SDHA PPGL cases to identify recurrence, metastasis or metachronous disease.

  • Surveillance screening for SDH-related disease should be performed in identified carriers of a pathogenic SDHA variant.

Open access

Bidhya Timilsina, Niranjan Tachamo, Prem Raj Parajuli and Ilan Gabriely

Summary

A 74-year-old woman presented with progressive lethargy, confusion, poor appetite and abdominal pain. She was found to have non-PTH-mediated severe hypercalcemia with renal failure and metabolic alkalosis. Extensive workup for hypercalcemia to rule out alternate etiology was unrevealing. Upon further questioning, she was taking excess calcium carbonate (Tums) for her worsening heartburn. She was diagnosed with milk-alkali syndrome (MAS). Her hypercalcemia and alkalosis recovered completely with aggressive hydration along with improvement in her renal function. High index of suspicion should be maintained and history of drug and supplements, especially calcium ingestion, should be routinely asked in patients presenting with hypercalcemia to timely diagnose MAS and prevent unnecessary tests and treatments.

Learning points:

  • Suspect milk-alkali syndrome in patients with hypercalcemia, metabolic alkalosis and renal failure, especially in context of ingestion of excess calcium-containing supplements.

  • Careful history of over-the-counter medications, supplements and diet is crucial to diagnose milk-alkali syndrome.

  • Milk-alkali syndrome may cause severe hypercalcemia in up to 25–30% of cases.

Open access

Ming Li Yee, Rosemary Wong, Mineesh Datta, Timothy Nicholas Fazio, Mina Mohammad Ebrahim, Elissa Claire Mcnamara, Gerard De Jong and Christopher Gilfillan

Summary

Mitochondrial diseases are rare, heterogeneous conditions affecting organs dependent on high aerobic metabolism. Presenting symptoms and signs vary depending on the mutation and mutant protein load. Diabetes mellitus is the most common endocrinopathy, and recognition of these patients is important due to its impact on management and screening of family members. In particular, glycemic management differs in these patients: the use of metformin is avoided because of the risk of lactic acidosis. We describe a patient who presented with gradual weight loss and an acute presentation of hyperglycemia complicated by the superior mesenteric artery syndrome. His maternal history of diabetes and deafness and a personal history of hearing impairment led to the diagnosis of a mitochondrial disorder.

Learning points:

  • The constellation of diabetes, multi-organ involvement and maternal inheritance should prompt consideration of a mitochondrial disorder.

  • Mitochondrial encephalomyopathy, lactic acidosis, stroke-like episodes (MELAS) and maternally inherited diabetes and deafness (MIDD) are the most common mitochondrial diabetes disorders caused by a mutation in m.3243A>G in 80% of cases.

  • Metformin should be avoided due to the risk of lactic acidosis.

  • There is more rapid progression to insulin therapy and higher prevalence of diabetic complications compared to type 2 diabetes.

  • Diagnosis of a mitochondrial disorder leads to family screening, education and surveillance for future complications.

  • Superior mesenteric artery syndrome, an uncommon but important cause of intestinal pseudo-obstruction in cases of significant weight loss, has been reported in MELAS patients.

Open access

Daniela Regazzo, Marina Paola Gardiman, Marily Theodoropoulou, Carla Scaroni, Gianluca Occhi and Filippo Ceccato

Summary

Tuberous sclerosis complex (TSC) is an autosomal dominant multisystem hereditary cutaneous condition, characterized by multiple hamartomas. In rare cases, pituitary neuroendocrine tumors (PitNETs) have been described in patients with TSC, but the causal relationship between these two diseases is still under debate. TSC is mostly caused by mutations of two tumor suppressor genes, encoding for hamartin (TSC1) and tuberin (TSC2), controlling cell growth and proliferation. Here, we present the case of a 62-year-old Caucasian woman with TSC and a silent gonadotroph PitNET with suprasellar extension, treated with transsphenoidal endoscopic neurosurgery with complete resection. Therapeutic approaches based on mTOR signaling (i.e. everolimus) have been successfully used in patients with TSC and tested in non-functioning PitNET cellular models with promising results. Here, we observed a reduction of cell viability after an in vitro treatment of PitNET’s derived primary cells with everolimus. TSC analysis retrieved no disease-associated variants with the exception of the heterozygous intronic variant c.4006-71C>T found in TSC2: the computational tools predicted a gain of a new splice site with consequent intron retention, not confirmed by an in vitro analysis of patient’s lymphocyte-derived RNA. Further analyses are therefore needed to provide insights on the possible mechanisms involving the hamartin-tuberin complex in the pathogenesis of pituitary adenomas. However, our data further support previous observations of an antiproliferative effect of everolimus on PitNET.

Learning points:

  • Pituitary neuroendocrine tumors (PitNET) in patients with tuberous sclerosis complex (TSC) are rare: only few cases have been reported in literature.

  • Therapeutic approach related to mTOR signaling, such as everolimus, may be used in some patients with PitNETs as well as those with TSC.

  • We reported a woman with both non-secreting PitNET and TSC; PitNET was surgically removed and classified as a silent gonadotroph tumor.

  • Everolimus treatment in PitNET’s-derived primary cells revealed a significant decrease in cell viability.

  • Considering our case and available evidence, it is still unclear whether a PitNET is a part of TSC or just a coincidental tumor.

Open access

Anne de Bray, Zaki K Hassan-Smith, Jamal Dirie, Edward Littleton, Swarupsinh Chavda, John Ayuk, Paul Sanghera and Niki Karavitaki

Summary

A 48-year-old man was diagnosed with a large macroprolactinoma in 1982 treated with surgery, adjuvant radiotherapy and bromocriptine. Normal prolactin was achieved in 2005 but in 2009 it started rising. Pituitary MRIs in 2009, 2012, 2014 and 2015 were reported as showing empty pituitary fossa. Prolactin continued to increase (despite increasing bromocriptine dose). Trialling cabergoline had no effect (prolactin 191,380 mU/L). In January 2016, he presented with right facial weakness and CT head was reported as showing no acute intracranial abnormality. In late 2016, he was referred to ENT with hoarse voice; left hypoglossal and recurrent laryngeal nerve palsies were found. At this point, prolactin was 534,176 mU/L. Just before further endocrine review, he had a fall and CT head showed a basal skull mass invading the left petrous temporal bone. Pituitary MRI revealed a large enhancing mass within the sella infiltrating the clivus, extending into the left petrous apex and occipital condyle with involvement of the left Meckel’s cave, internal acoustic meatus, jugular foramen and hypoglossal canal. At that time, left abducens nerve palsy was also present. CT thorax/abdomen/pelvis excluded malignancy. Review of previous images suggested that this lesion had started becoming evident below the fossa in pituitary MRI of 2015. Temozolomide was initiated. After eight cycles, there is significant tumour reduction with prolactin 1565 mU/L and cranial nerve deficits have remained stable. Prolactinomas can manifest aggressive behaviour even decades after initial treatment highlighting the unpredictable clinical course they can demonstrate and the need for careful imaging review.

Learning points:

  • Aggressive behaviour of prolactinomas can manifest even decades after first treatment highlighting the unpredictable clinical course these tumours can demonstrate.

  • Escape from control of hyperprolactinaemia in the absence of sellar adenomatous tissue requires careful and systematic search for the anatomical localisation of the lesion responsible for the prolactin excess.

  • Temozolomide is a valuable agent in the therapeutic armamentarium for aggressive/invasive prolactinomas, particularly if they are not amenable to other treatment modalities.

Open access

Kate Laycock, Abhijit Chaudhuri, Charlotte Fuller, Zahra Khatami, Frederick Nkonge and Nemanja Stojanovic

Summary

Hashimoto’s encephalopathy (HE) is rarely reported with only a few hundred cases published. Diagnosis is made in patients with an appropriate clinical picture and high antithyroperoxidase (anti-TPO) antibodies after infectious, toxic and metabolic causes of encephalopathy have been excluded. There is little objective data on the neurocognitive impairment in patients with HE and their improvement with treatment. We present the case of a 28-year-old woman with HE. Approach to management was novel as objective neuropsychological assessment was used to assess her clinical condition and response to treatment. Intravenous immunoglobulin (IVIg) as the first-line treatment instead of steroids. She responded well. The case illustrates that a different approach is required for the diagnosis and treatment of HE. A new diagnostic criteria is proposed that includes neurocognitive assessment, serum and CSF antibodies, an abnormal EEG and exclusion of other causes of encephalopathy. Furthermore, treatment should be tailored to the patient.

Learning points:

  • Neurocognitive assessment should be carried out to assess the extent of brain involvement in suspected Hashimoto’s encephalopathy pre- and post- treatment.

  • Treatment of Hashimoto’s encephalopathy should be tailored to the patient.

  • Unifying diagnostic criteria for Hashimoto’s encephalopathy must be established.

Open access

Snezana Burmazovic, Christoph Henzen, Lukas Brander and Luca Cioccari

Summary

The combination of hyperosmolar hyperglycaemic state and central diabetes insipidus is unusual and poses unique diagnostic and therapeutic challenges for clinicians. In a patient with diabetes mellitus presenting with polyuria and polydipsia, poor glycaemic control is usually the first aetiology that is considered, and achieving glycaemic control remains the first course of action. However, severe hypernatraemia, hyperglycaemia and discordance between urine-specific gravity and urine osmolality suggest concurrent symptomatic diabetes insipidus. We report a rare case of concurrent manifestation of hyperosmolar hyperglycaemic state and central diabetes insipidus in a patient with a history of craniopharyngioma.

Learning points:

  • In patients with diabetes mellitus presenting with polyuria and polydipsia, poor glycaemic control is usually the first aetiology to be considered.

  • However, a history of craniopharyngioma, severe hypernatraemia, hyperglycaemia and discordance between urine-specific gravity and osmolality provide evidence of concurrent diabetes insipidus.

  • Therefore, if a patient with diabetes mellitus presents with severe hypernatraemia, hyperglycaemia, a low or low normal urinary-specific gravity and worsening polyuria despite correction of hyperglycaemia, concurrent diabetes insipidus should be sought.

Open access

Jordan Yardain Amar, Kimberly Borden, Elizabeth Watson and Talin Arslanian

Summary

Isolated Growth Hormone Deficiency (IGHD) is a rare cause of short stature, treated with the standard regimen of subcutaneous synthetic growth hormone (GH). Patients typically achieve a maximum height velocity in the first year of treatment, which then tapers shortly after treatment is stopped. We report a case of a 9-year-old male who presented with short stature (<3rd percentile for age and race). Basal hormone levels showed undetectable serum IGF1. Skeletal wrist age was consistent with chronologic age. Cranial MRI revealed no masses or lesions. Provocative arginine-GH stimulation testing demonstrated a peak GH level of 1.4 ng/mL. Confirmatory genetic testing revealed a rare autosomal recessive single-nucleotide polymorphism (SNP) with mutational frequency of 2%. GH supplementation was started and pursued for 2 years, producing dramatically increased height velocity. This velocity persisted linearly through adolescence, several years after treatment had been discontinued. Final adult height was >95th percentile for age and race. In conclusion, this is a case of primary hypopituitarism with differential diagnosis of IGHD vs Idiopathic Short Stature vs Constitutional Growth Delay. This case supports two objectives: Firstly, it highlights the importance of confirmatory genetic testing in patients with suspected, though diagnostically uncertain, IGHD. Secondly, it demonstrates a novel secondary growth pattern with implications for better understanding the tremendous variability of GH treatment response.

Learning points:

  • GHD is a common cause of growth retardation, and IGHD is a specific subtype of GHD in which patients present solely with short stature.

  • The standard treatment for IGHD is subcutaneous synthetic GH until mid-parental height is reached, with peak height velocity attained in the 1st year of treatment in the vast majority of patients.

  • Genetic testing should be strongly considered in cases of diagnostic uncertainty prior to initiating treatment.

  • Future investigations of GH treatment response that stratify by gene and specific mutation will help guide treatment decisions.

  • Response to treatment in patients with IGHD is variable, with some patients demonstrating little to no response, while others are ‘super-responders.’

Open access

Hans-Christof Schober, Christian Kneitz, Franziska Fieber, Kathrin Hesse and Henry Schroeder

Summary

Tumor-induced osteomalacia (TIO) is caused by the hormone fibroblast growth factor 23 (FGF-23). It is mainly produced in the tissue of mesenchymal tumors. Patients with TIO frequently suffer from a chronic decompensated pain syndrome and/or muscle weakness with postural deformity. Despite the severity of the disease, the diagnosis is frequently established late. In some cases, it takes several years to establish the condition. This case report concerning a 68-year old woman demonstrates the selective blood sampling for FGF-23 as path-breaking diagnostics to confirm the diagnosis of a neuroendocrine tumor.

Learning points:

  • Tumor-induced osteomalacia is a rare condition compared to other paraneoplastic syndromes.

  • It causes complex symptoms such as progressive reduction of physical capacity, exhaustion, fatigue, a decompensated pain syndrome of the musculoskeletal system and fractures of several bones.

  • Elevated serum levels of FGF-23 implicate massive phosphate elimination and resulting hypophosphatemia.

  • The diagnosis is often established over a period of several years because the localization of small FGF-23-producing tumors is complicated.

  • It is the combination of MRI and selective blood sampling for FGF-23 which permits reliable identification of tumors causing TIO and leads to accurate localization.

  • In a patient with generalized pain and reduced physical capacity, osteological parameters such as phosphate, 25-OH vitamin D3 and 1,25-(OH)2D3, as well as bone-specific alkaline phosphatase levels in serum should be determined. Hypophosphatemia should always lead to further diagnostic investigations aiming at the detection of an FGF-23-producing tumor.

Open access

Kingsley Okolie, Sumathy Perampalam, Anthony Barker and Christopher J Nolan

Klinefelter syndrome (KS) is a chromosomal disorder affecting males, with the typical karyotype of 47,XXY due to a supernumerary X chromosome, which causes progressive testicular failure resulting in androgen deficiency and infertility. Despite it being the most common sex chromosomal disorder, its diagnosis is easily missed. In addition to its classical clinical features of tall stature, gynaecomastia, small testes, and symptoms and signs of hypogonadism including infertility, KS is also often associated with neurocognitive, behavioural and psychiatric disorders.

We present a 44-year-old man with KS who, despite having erectile dysfunction, paradoxically had increased libido. He used sildenafil to overcome his erectile dysfunction. Hypersexuality was manifested by very frequent masturbation, multiple sexual partners most of whom were casual, and a sexual offence conviction at the age of 17 years.

Discussion focuses on the frequent failure of clinicians to diagnose KS, the neurocognitive, behavioural and psychiatric aspects of KS, this unusual presentation of hypersexuality in a man with KS, and the challenges of medical management of hypogonadism in a man with a history of a sexual offence.

Learning points:

  • Klinefelter syndrome (KS) is common in men (about 1 in 600 males), but the diagnosis is very often missed.

  • In addition to classic features of hypogonadism, patients with KS can often have associated neurocognitive, behavioural and/or psychiatric disorders.

  • More awareness of the association between KS and difficulties related to verbal skills in boys could improve rates of early diagnosis and prevent longer-term psychosocial disability.

  • Hypersexuality in the context of hypogonadism raises the possibility of sex steroid independent mechanistic pathways for libido.

  • Testosterone replacement therapy in KS with hypersexuality should be undertaken with caution using a multidisciplinary team approach.