Natural history of non-functioning pituitary microadenomas - results from the UK NFPA consortium

OBJECTIVE

The optimal approach to the surveillance of non-functioning pituitary microadenomas (micro-NFPAs) is not clearly established. Our aim was to generate evidence on the natural history of micro-NFPAs to support patient care.

DESIGN

Multi-centre, retrospective, cohort study involving 23 endocrine departments (UK NFPA consortium).

METHODS

Clinical, imaging, and hormonal data of micro-NFPA cases between 1/1/2008 and 21/12/2021 were analysed.

RESULTS

Data for 459 patients were retrieved [median age at detection 44 years [interquartile range (IQR) 31-57) - 152 males/307 females]. 419 patients had more than two MRIs [median imaging monitoring 3.5 years (IQR 1.71-6.1)]. One case developed apoplexy. Cumulative probability of micro-NFPA growth was 7.8% (95%CI 4.9%-8.1%) and 14.5% (95%CI 10.2%-18.8%) at 3 and 5 years, respectively, and of reduction 14.1% (95%CI 10.4-17.8%) and 21.3% (95%CI 16.4-26.2%) at 3 and 5 years, respectively. Median tumour enlargement was 2 mm (IQR 1-3) and 49% of micro-NFPAs that grew became macroadenomas (nearly all >5 mm at detection). Eight (1.9%) patients received surgery (only one had visual compromise with surgery required >3 years after micro-NFPA detection). Sex, age, size at baseline were not predictors of enlargement/reduction. At time of detection, 7.2%, 1.7% and 1.5% patients had secondary hypogonadism, hypothyroidism and hypoadrenalism, respectively. Two (0.6%) developed hypopituitarism during follow-up (after progression to macroadenoma).

CONCLUSIONS

Probability of micro-NFPA growth is low and development of new hypopituitarism is rare. Delaying first follow-up MRI to three years and avoiding hormonal re-evaluation in absence of tumour growth or clinical manifestations is a safe approach for micro-NFPA surveillance.

LBMON62 Central Diabetes Insipidus From A Patients’ Perspective- From Management To Psychological Co-morbidities And Re-naming Of The Condition

Background

Central diabetes insipidus (cDI) is a rare neuroendocrine condition characterized by deficiency of arginine vasopressin. Data about treatment-related side effects, psychological co-morbidities, and incidence of wrong management due to confusion with diabetes mellitus (DM) are scarce and limited to small studies. Furthermore, increasing interest has arisen on a potential need for re-naming the condition.

Methods

Web-based anonymous survey, developed by a team of endocrinologists and patient representatives covering issues from management of the condition and quality of life to lack of awareness amongst medical professionals. Patients were provided with the link to the online survey either via their physician during routine check-ups or the homepages of the UK Pituitary Foundation, Pituitary World News, Facebook group 'Got Diabetes Insipidus?', and Pituitary Society.

Findings: In total, 1034 patients with cDI, 47%(n=488) with isolated posterior and 53%(n=546) with combined anterior/posterior pituitary dysfunction, participated. Median [IQR] age was 42[32, 53]. Duration of cDI was 9. 0[3. 0, 19. 0] years and its aetiologies were idiopathic 30%(n=315), tumors/cysts (pre-surgical 21%(n=217), post-surgical 25%(n=254)), inflammatory/autoimmune 6%(n=61), infiltrative diseases 6%(n=62), genetic 4%(n=44), head trauma 3%(n=34), and other causes 5%(n=47). Ninety-six percent (n=994) were on desmopressin therapy - oral tablets 56%(n=575), nasal spray 23%(n=233), and sublingual tablets 12%(n=126). Among these, 26%(n=273) experienced hyponatremia at least once whilst on desmopressin. Patients who routinely omitted desmopressin to allow aquaresis had a significantly lower risk of hyponatremia compared to those not aware of this approach (OR 0.63; 95%-CI 0.42-0.92; p<0. 018). Sixty-four percent (n=660) reported low quality of life with 6[4-7] out of 10 points on a visual analogue scale. Thirty-six percent (n=369, equally prevalent in isolated posterior and combined pituitary dysfunction) experienced psychological problems after the diagnosis, of whom 70%(n=258) reported higher anxiety levels, 71%(n=263) sleep disturbances, and 65%(n=239) depressed mood. Eighty percent (n=823) encountered a situation where medical professionals, friends or family members confused the diagnosis with DM, of these, 88%(n=637) indicated that this confusion affected the management of their cDI. In total, 85% (n= 884) would prefer a re-naming of the condition; amongst those, the most common suggestion was 'vasopressin deficiency'.

Interpretation: This is the so far largest survey conducted in patients with cDI using a web-based method and patient involvement in the survey development. We show a high percentage of treatment-related side effects, high prevalence of psychological co-morbidities and clear need for re-naming the condition from patients’ perspective.

Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Central diabetes insipidus from a patient's perspective: management, psychological co-morbidities, and renaming of the condition: results from an international web-based survey

BACKGROUND

Central diabetes insipidus is a rare neuroendocrine condition. Data on treatment-associated side-effects, psychological comorbidities, and incorrect management are scarce. The aim of this study was to investigate patients' perspectives on their disease.

METHODS

This study used a cross-sectional, web-based, anonymous survey, developed by endocrinologists and patient representatives, to collect the opinions of patients with central diabetes insipidus on management and complications of their disease, psychological comorbidities, degree of knowledge and awareness of the condition among health-care professionals, and renaming the disease to avoid confusion with diabetes mellitus (diabetes).

FINDINGS

Between Aug 23, 2021, and Feb 7, 2022, 1034 patients with central diabetes insipidus participated in the survey. 91 (9%) participants were children and adolescents (37 [41%] girls and 54 [59%] boys; median age 10 years [IQR 6-15]) and 943 (91%) were adults (757 [80%] women and 186 [20%] men]; median age 44 years [34-54]). 488 (47%) participants had isolated posterior pituitary dysfunction and 546 (53%) had combined anterior and posterior pituitary dysfunction. Main aetiologies were idiopathic (315 [30%] of 1034 participants) and tumours and cysts (pre-surgical 217 [21%]; post-surgical 254 [25%]). 260 (26%; 95% CI [0·23-0·29]) of 994 patients on desmopressin therapy had hyponatraemia leading to hospitalisation. Patients who routinely omitted or delayed desmopressin to allow intermittent aquaresis had a significantly lower prevalence of hyponatraemia compared with those not aware of this approach (odds ratio 0·55 [95% CI 0·39-0·77]; p=0·0006). Of patients who had to be hospitalised for any medical reason, 71 (13%; 95% CI 0·10-0·16) of 535 patients did not receive desmopressin while in a fasting state (nil by mouth) without intravenous fluid replacement and reported symptoms of dehydration. 660 (64%; 0·61-0·67) participants reported lower quality of life, and 369 (36%; 0·33-0·39) had psychological changes subjectively associated with their central diabetes insipidus. 823 (80%; 0·77-0·82) participants encountered a situation where central diabetes insipidus was confused with diabetes mellitus (diabetes) by health-care professionals. 884 (85%; 0·83-0·88) participants supported renaming the disease; the most favoured alternative names were vasopressin deficiency and arginine vasopressin deficiency.

INTERPRETATION

This is the largest survey of patients with central diabetes insipidus, reporting a high prevalence of treatment-associated side-effects, mismanagement during hospitalisation, psychological comorbidities, and a clear support for renaming the disease. Our data are the first to indicate the value of routinely omitting or delaying desmopressin.

FUNDING

Swiss National Science Foundation, Swiss Academy of Medical Sciences, and G&J Bangerter-Rhyner-Foundation.

Succinate dehydrogenase and MYC-associated factor X mutations in pituitary neuroendocrine tumours

Pituitary neuroendocrine tumours (PitNETs) associated with paragangliomas or phaeochromocytomas are rare. SDHx variants are estimated to be associated with 0.3-1.8% of PitNETs. Only a few case reports have documented the association with MAX variants. Prolactinomas are the most common PitNETs occurring in patients with SDHx variants, followed by somatotrophinomas, clinically non-functioning tumours and corticotrophinomas. One pituitary carcinoma has been described. SDHC, SDHB and SDHA mutations are inherited in an autosomal dominant fashion and tumorigenesis seems to adhere to Knudson's two-hit hypothesis. SDHD and SDHAF2 mutations most commonly have paternal inheritance. Immunohistochemistry for SDHB or MAX and loss of heterozygosity analysis can support the assessment of pathogenicity of the variants. Metabolomics is promising in the diagnosis of SDHx-related disease. Future research should aim to further clarify the role of SDHx and MAX variants or other genes in the molecular pathogenesis of PitNETs, including pseudohypoxic and kinase signalling pathways along with elucidating epigenetic mechanisms to predict tumour behaviour.

Osteopetrosis - A Case Series Exploring Complications and Multidisciplinary Management

Background: Osteopetrosis is a group of rare inherited skeletal dysplasias, with each variant sharing the hallmark of increased bone mineral density (BMD). Abnormal osteoclast activity produces overly dense bone predisposing to fracture and skeletal deformities. Whilst no cure for these disorders exists, endocrinologists play an important role in surveillance and management of complications.

Clinical Cases: A 43-year-old female had findings suggestive of increased BMD on radiographic imaging performed to investigate shoulder and back pain. X-ray of lumbar spine demonstrated a ‘rugger jersey’ spine appearance, while shoulder X-ray revealed mixed lucency and sclerosis of the humeral head. DXA scan showed T-scores of +11 at the hip and +12.5 at the lumbar spine. MRI of head displayed bilateral narrowing and elongation of the internal acoustic meatus and narrowing of the orbital foramina. Genetic assessment confirmed autosomal dominant osteopetrosis with a CLCN7 variant. Oral colecalciferol supplementation was commenced and multi-disciplinary management instigated with referral to ophthalmology and ENT teams. A 25-year-old male presented with a seven-year history of low back pain and prominent bony swelling around the tibial tuberosities and nape of neck. Past medical history included repeated left scaphoid fracture in 2008 and 2018. Recovery from his scaphoid fracture was complicated by non-union requiring bone grafting with open reduction and fixation. Plain X-rays of the spine again demonstrated ‘rugger jersey’ spine. DXA scan was notable for elevated T scores; +2.9 at hip and +5.8 lumbar spine. MRI spine showed vertebral endplate cortical thickening and sclerosis at multiple levels. The patient declined genetic testing and is under clinical review. A 62-year-old male was referred to the bone metabolism service following a DXA scan showing T scores of +11. 7 at the hip and +13 at the lumbar spine. His primary complaint was of neck pain and on MRI there was multi-level nerve root impingement secondary to facet joint hypertrophy. Past medical history was significant for a long history of widespread joint pains; previous X-ray reports described generalized bony sclerosis up to 11 years previously. Clinical and radiological monitoring continues. Conclusion: Individuals with osteopetrosis require a multidisciplinary approach to management. There is no curative treatment and mainstay of therapy is supportive with active surveillance for complications.

Corticotroph Aggressive Pituitary Tumors and Carcinomas Frequently Harbor ATRX Mutations

CONTEXT

Aggressive pituitary tumors (APTs) are characterized by unusually rapid growth and lack of response to standard treatment. About 1% to 2% develop metastases being classified as pituitary carcinomas (PCs). For unknown reasons, the corticotroph tumors are overrepresented among APTs and PCs. Mutations in the alpha thalassemia/mental retardation syndrome X-linked (ATRX) gene, regulating chromatin remodeling and telomere maintenance, have been implicated in the development of several cancer types, including neuroendocrine tumors.

OBJECTIVE

To study ATRX protein expression and mutational status of the ATRX gene in APTs and PCs.

DESIGN

We investigated ATRX protein expression by using immunohistochemistry in 30 APTs and 18 PCs, mostly of Pit-1 and T-Pit cell lineage. In tumors lacking ATRX immunolabeling, mutational status of the ATRX gene was explored.

RESULTS

Nine of the 48 tumors (19%) demonstrated lack of ATRX immunolabelling with a higher proportion in patients with PCs (5/18; 28%) than in those with APTs (4/30;13%). Lack of ATRX was most common in the corticotroph tumors, 7/22 (32%), versus tumors of the Pit-1 lineage, 2/24 (8%). Loss-of-function ATRX mutations were found in all 9 ATRX immunonegative cases: nonsense mutations (n = 4), frameshift deletions (n = 4), and large deletions affecting 22-28 of the 36 exons (n = 3). More than 1 ATRX gene defect was identified in 2 PCs.

CONCLUSION

ATRX mutations occur in a subset of APTs and are more common in corticotroph tumors. The findings provide a rationale for performing ATRX immunohistochemistry to identify patients at risk of developing aggressive and potentially metastatic pituitary tumors.

New Treatments for the Carcinoid Syndrome

Neuroendocrine tumors, including carcinoids, are rare and insidiously growing tumors. Related to their site of origin, tumors can be functional, causing various forms of the carcinoid syndrome, owing to the overproduction of serotonin, histamine, or other bioactive substances. They often invade adjacent structures or metastasize to the liver and elsewhere. Treatment includes multimodal approaches, including cytoreductive surgery, locoregional embolization, cytotoxic therapy, peptide receptor radionuclide therapy, and various targeted therapies with goals of symptom relief and control of tumor growth. This article summarizes current and emerging approaches to management and reviews several promising future therapies.