Pituitary tumours without distinct lineage differentiation express stem cell marker SOX2.

CONTEXT: The recent WHO 2022 Classification of pituitary tumours identified a novel group of 'plurihormonal tumours without distinct lineage differentiation (WDLD)'. By definition, these express multiple combinations of lineage commitment transcription factors, in a monomorphous population of cells. OBJECTIVES: To determine the expression of stem cell markers (SOX2, Nestin, CD133) within tumours WDLD, immature PIT-1 lineage and acidophil stem cell tumours, compared with committed cell lineage tumours. METHODS: Retrospective evaluation of surgically resected pituitary tumours from St Vincent's Hospital, Sydney. Patients were selected to cover a range of tumour types, based on transcription factor and hormone immunohistochemistry. Clinical data was collected from patient files. Radiology reports were reviewed for size and invasion. Samples were analysed by immunohistochemistry and RT-qPCR for SF-1, PIT-1, T-PIT, SOX2, Nestin and CD133. Stem cell markers were compared between tumours WDLD and those with classically "mature" types. RESULTS: On immunohistochemistry, SOX2 was positive in a higher proportion of tumours WDLD compared with those meeting WHO lineage criteria, 7/10 v 10/42 (70 v 23.4%, p = 0.005). CD133 was positive in 2/10 tumours WDLD but 0/41 meeting lineage criteria, P = 0.003. On RT-qPCR, there was no significant difference in relative expression of stem cell markers (SOX2, CD133, Nestin) between tumours with and WDLD. CONCLUSIONS: Our study is the first to biologically characterise pituitary tumours WDLD. We demonstrate that these tumours exhibit a higher expression of the stem cell marker SOX2 compared with other lineage-differentiated tumours, suggesting possible involvement of stem cells in their development.

Changing the name of diabetes insipidus: a position statement of The Working Group for Renaming Diabetes Insipidus.

"What's in a name? That which we call a rose/By any other name would smell as sweet." (Juliet, from Romeo and Juliet by William Shakespeare). Shakespeare's implication is that a name is nothing but a word and it therefore represents a convention with no intrinsic meaning. Whilst this may be relevant to romantic literature, disease names do have real meanings, and consequences, in medicine. Hence, there must be a very good rational for changing the name of a disease that has a centuries-old historical context. A working group of representatives from national and international endocrinology and pediatric endocrine societies now proposes changing the name of "diabetes insipidus" to "Arginine Vasopressin Deficiency (AVP-D)" for central etiologies, and "Arginine Vasopressin Resistance (AVP-R)" for nephrogenic etiologies. This editorial provides both the historical context and the rational for this proposed name change.

Towards precision medicine for clinically non-functioning pituitary tumours.

OBJECTIVE: Clinically non-functioning pituitary tumours (NFPT) are a heterogenous group of neoplasms with diverse outcomes. The purpose of this narrative review was to summarize available data on predictive factors, both in routine practice and research settings. DESIGN: A literature review was conducted for papers published in peer-reviewed journals, investigating clinical, radiological, pathological and genetic predictive factors in NFPT. RESULTS: Several clinical and radiological factors have been associated with NFPT recurrence and/or aggressiveness, including larger size and pre-/post-operative growth rates. Application of transcription factor immunohistochemistry has given rise to improved subtype identification, including 'higher-risk' subtypes, in routine clinical practice. Numerous other pathological and genetic biomarkers have demonstrated promise for prognostication in the research setting. CONCLUSION: NFPT are a heterogenous group of tumours, characterized by diverse presentation, pathogenesis and outcomes. Ongoing refinements in understanding of tumour biology are likely to pave the way to improved integrative prognostication and precision medicine for NFPT.

Prolactin correction for adequacy of petrosal sinus cannulation may diminish diagnostic accuracy in Cushing's disease.

OBJECTIVE: Petrosal venous prolactin concentrations have been promoted to improve the diagnostic accuracy of inferior petrosal sinus sampling (IPSS), beyond that achieved with ACTH measurement alone, in diagnosing a pituitary ACTH source and determining corticotrophinoma side (L/R). Our objective was to assess the effect of using prolactin to confirm adequacy of petrosal cannulation in a cohort of patients with ACTH-dependent Cushing's syndrome. DESIGN: Retrospective cohort study. PATIENTS: Thirteen patients with clinical and biochemical Cushing's syndrome who underwent IPSS. MEASUREMENTS: Serum prolactin and ACTH in peripheral and inferior petrosal sinus blood before and after corticotrophin-releasing hormone (CRH) injection. RESULTS: Thirteen consecutive patients were diagnosed with Cushing's disease using uncorrected ACTH ratios. The side of PRL excess was the same as the side of ACTH excess in all cases. Use of various published prolactin-related equations suggested that the ACTH non-dominant side was not cannulated in four, six or seven patients depending on the equation used. The equations generally decreased the central-to-peripheral gradient on the uncorrected ACTH dominant side, increased the central-to-peripheral gradient on the contralateral side and diminished or even reversed the ACTH intersinus gradient. CONCLUSIONS: Consistent co-lateralisation of prolactin and ACTH in IPSS strongly suggests that prolactin cannot act as an independent guide to the diagnosis and lateralisation of Cushing's disease. All patients with Cushing's disease had a prolactin intersinus gradient towards the tumourous side of the pituitary, for likely biological reasons. PRL-corrected ACTH concentrations may threaten the sensitivity and specificity of IPSS in diagnosing Cushing's disease and conceal lateralisation.

Approach to the patient: New era emerges for craniopharyngioma management.

Papillary craniopharyngioma (PCP) and adamantinomatous craniopharyngioma (ACP) are distinct, slow growing tumors of the suprasellar region. Their location, composition and biology have historically evaded successful surgical, radiation, and medical therapy. Meanwhile compromise of critical structures either by tumor or treatments increase morbidity, impacting patient and carer quality of life. There has been a paradigm shift in the management of PCP, stemming from the discovery of BRAFV600E mutation in its tumorigenesis. Such a treatment breakthrough may soon be the case for ACP, changing the landscape of craniopharyngioma management. We use a case of ACP, partially responding to ERK inhibitor therapy to demonstrate chronicity of disease progression and discuss modern management strategies highlighting the importance of access to tumour agnostic clinical trials, and future directions.

The evolution in pituitary tumour classification: a clinical perspective.

Objective: Pituitary tumours comprise a pathologically and clinically diverse group of neoplasms. Classification frameworks have changed dramatically in the past two decades, reflecting improving understanding of tumour biology. This narrative review examines the evolution of pituitary tumour classification, from a clinical perspective. Results: In 2004, pituitary tumours were classified as 'typical' or 'atypical', based on the presence of markers of proliferation, Ki67, mitotic count and p53. In 2017, the new WHO marked a major paradigm shift, with a new focus on lineage-based classification, determined by transcription factor and hormonal immunohistochemistry. The terms 'typical' and 'atypical' were omitted, though the importance of proliferative markers Ki67 and mitotic count was acknowledged. The recent WHO 2022 classification incorporates further refinements, specifically recognising some less common types that may represent less well-differentiated tumours. Whilst 'high risk' tumour types have been identified, further work is still required to improve prognostication. Conclusions: Recent WHO classifications have marked significant progress in the diagnostic evaluation of pituitary tumours, though shortcomings and challenges remain for both clinicians and pathologists in managing these tumours.

Predictors of pituitary tumour behaviour: an analysis from long-term follow-up in 2 tertiary centres.

OBJECTIVES: To determine the clinical utility of assessment of tumour invasion, markers of proliferation, and the French clinicopathological classification in pituitary tumour prognostication. METHODS: This is a retrospective evaluation of adult patients undergoing pituitary surgery at Oxford University and St Vincent's Hospitals, between 1989 and 2016, with at least 12 months of clinical data. Invasion was assessed radiologically, proliferative markers (Ki67, mitotic count, p53) by immunohistochemistry. Tumours were graded according to the clinicopathological classification. Intra- and interlaboratory variability of histopathology reporting was evaluated. OUTCOMES: (1) Tumour recurrence (radiological or reintervention ≥12 months postoperatively) and/or (2) "aggressive behaviour" (≥4 interventions and/or invasive tumour with recurrence/reintervention between 12 and 24 months postoperatively). RESULTS: A total of 386 patients were included, age at surgery was 56 (interquartile range [IQR] 41-67) years, 54% were male, and median follow-up was 90 months (range 44-126). Tumours were predominantly clinically nonfunctioning (252, 65%), with overall 53% invasive, and 10% that demonstrated ≥2 proliferative marker positivity. Recurrence was predicted by invasiveness (hazards ratio [HR] 1.6 [1.10-2.37], P .02), elevated mitotic count (HR 2.17 [1.21-3.89], P .01), grade (2b vs 1a HR 2.32 [1.06-5.03], P .03), and absence of gross total resection (HR 3.70 [1.72-8.00], P .01). Clinically defined aggressiveness was associated with elevated Ki67, mitotic count, and invasiveness. Ki67 reporting methodologies showed moderate correlation across laboratories (Phi 0.620), whereas p53 reporting reproducibility was poor (Phi 0.146). CONCLUSIONS: Proliferative markers, including Ki67 and mitotic count, but not p53, are important in predicting the development of aggressive pituitary tumour behaviour.

Female Representation: Australian Diabetes and Endocrinology Societies.

Background: Endocrinology has one of the highest proportions of female specialists and trainees, however females have traditionally been underrepresented in leadership positions and as speakers at scientific meetings. Hypothesis: Females would represent less than half of invited speakers (plenary, symposium sessions) at endocrinology conferences and in leadership positions of endocrinology societies. Method: An audit of Australian diabetes and endocrinology societies and their respective annual scientific meetings between 2016 - 2020. Analysis of the gender of conference speakers across oral, symposium and plenary sessions, session chairs, program organising committees and society committees. Results: A total of 1638 speakers (females 856, 52.3%) across 550.4 hours (females 273.6, 49.7%) of presentations at the conferences were identified. Among plenary sessions of all 3 societies there were more male (61%) than female speakers. A total of 608 session chairs were identified, with 313 (51.5%) females. The majority of organising committee members (n=116) were female (56%), however the representation across each organising committee varied. There was a low proportion of society female council members (39% female). Conclusion: There was an equal representation of females and males as conference speakers and session chairs. However, there was an underrepresentation of women in more prestigious roles of plenary speakers and society council members. We implore conscious efforts to address this disparity.

Changing the name of diabetes insipidus: a position statement of The Working Group for Renaming Diabetes Insipidus.

'What's in a name? That which we call a rose/By any other name would smell as sweet.' (Juliet, from Romeo and Juliet by William Shakespeare). Shakespeare's implication is that a name is nothing but a word and it therefore represents a convention with no intrinsic meaning. Whilst this may be relevant to romantic literature, disease names do have real meanings, and consequences, in medicine. Hence, there must be a very good rationale for changing the name of a disease that has a centuries-old historical context. A working group of representatives from national and international endocrinology, nephrology and pediatric societies now proposes changing the name of 'diabetes insipidus' to 'arginine vasopressin deficiency (AVP-D)' for central etiologies and 'arginine vasopressin resistance (AVP-R)' for nephrogenic etiologies. This editorial provides both the historical context and the rationale for this proposed name change.

Changing the name of diabetes insipidus: a position statement of The Working Group for Renaming Diabetes Insipidus.

'What's in a name? That which we call a rose/By any other name would smell as sweet' (Juliet, from Romeo and Juliet by William Shakespeare). Shakespeare's implication is that a name is nothing but a word, and it therefore represents a convention with no intrinsic meaning. While this may be relevant to romantic literature, disease names do have real meanings, and consequences, in medicine. Hence, there must be a very good rationale for changing the name of a disease that has a centuries-old historical context. A working group of representatives from national and international endocrinology, and pediatric endocrine societies now proposes changing the name of 'diabetes insipidus' to 'arginine vasopressin deficiency (AVP-D)' for central etiologies, and 'arginine vasopressin resistance (AVP-R)' for nephrogenic etiologies. This article provides both the historical context and the rationale for this proposed name change.

Safety of growth hormone replacement in survivors of cancer and intracranial and pituitary tumours: a consensus statement.

Growth hormone (GH) has been used for over 35 years, and its safety and efficacy has been studied extensively. Experimental studies showing the permissive role of GH/insulin-like growth factor 1 (IGF-I) in carcinogenesis have raised concerns regarding the safety of GH replacement in children and adults who have received treatment for cancer and those with intracranial and pituitary tumours. A consensus statement was produced to guide decision-making on GH replacement in children and adult survivors of cancer, in those treated for intracranial and pituitary tumours and in patients with increased cancer risk. With the support of the European Society of Endocrinology, the Growth Hormone Research Society convened a Workshop, where 55 international key opinion leaders representing 10 professional societies were invited to participate. This consensus statement utilized: (1) a critical review paper produced before the Workshop, (2) five plenary talks, (3) evidence-based comments from four breakout groups, and (4) discussions during report-back sessions. Current evidence reviewed from the proceedings from the Workshop does not support an association between GH replacement and primary tumour or cancer recurrence. The effect of GH replacement on secondary neoplasia risk is minor compared to host- and tumour treatment-related factors. There is no evidence for an association between GH replacement and increased mortality from cancer amongst GH-deficient childhood cancer survivors. Patients with pituitary tumour or craniopharyngioma remnants receiving GH replacement do not need to be treated or monitored differently than those not receiving GH. GH replacement might be considered in GH-deficient adult cancer survivors in remission after careful individual risk/benefit analysis. In children with cancer predisposition syndromes, GH treatment is generally contraindicated but may be considered cautiously in select patients.

Aggressive pituitary tumours: the role of temozolomide and the assessment of MGMT status.

BACKGROUND: Aggressive pituitary tumours are associated with substantial morbidity and mortality. Treatment options are often limited, and chemotherapy has been reserved as salvage therapy although historically results have often been disappointing. However, temozolomide, an oral alkylating agent, has recently demonstrated significant activity against these tumours. A DNA repair protein, 06-methylguanine-DNA methyltransferase (MGMT) has been suggested as a biomarker to predict response to temozolomide in pituitary tumours. MATERIALS AND METHODS: This paper will review the current literature on temozolomide and pituitary tumours and discuss the recent controversy surrounding the value of determining the MGMT status in this tumour group. A PubMed search was performed to retrieve articles, using the terms 'pituitary tumour' and 'temozolomide'. RESULTS: Overall, 24/40 (60%) of the published cases demonstrated a response to temozolomide therapy. The highest response rates were seen amongst prolactinomas (73%) and ACTH-secreting tumours (60%), whilst nonfunctioning pituitary tumours exhibit lower response rates (40%). Responsivity is typically evident in the first 3 months of therapy and may be dramatic and sustained. Low MGMT expression, as determined by immunohistochemistry, is associated with a high response rate (76%), whilst high MGMT expression has not been associated with responses. MGMT promoter methylation does not correlate with temozolomide response. CONCLUSIONS: Temozolomide is the first chemotherapeutic agent to show substantial response rates in aggressive pituitary tumours. MGMT immunohistochemistry, but not MGMT methylation analysis, shows promise as a predictive tool. Prospective clinical trials are now necessary to more accurately determine the efficacy of this agent in this patient group.

Transcription factor immunohistochemistry in the diagnosis of pituitary tumours.

OBJECTIVE: The clinical utility and prognostic value of WHO 2017 lineage-based classification of pituitary tumours have not been assessed. This study aimed to (1) determine the clinical utility of transcription factor analysis for classification of pituitary tumours and (2) determine the prognostic value of improved lineage-based classification of pituitary tumours. METHODS: This was a retrospective evaluation of patients who underwent surgical resection of pituitary tumours at St Vincent's Public and Private Hospitals, Sydney, Australia between 1990 and 2016. Included patients were at least 18 years of age and had complete histopathological data, forming the 'histological cohort'. Patients with at least 12 months of post-surgical follow-up were included in the subgroup 'clinical cohort'. The diagnostic efficacy of transcription factor immunohistochemistry in conjunction with hormone immunohistochemistry was compared with hormone immunohistochemistry alone. The prognostic value of identifying 'higher-risk' histological subtypes was assessed. RESULTS: There were 171 patient tumour samples analyzed in the histological cohort. Of these, there were 95 patients forming the clinical cohort. Subtype diagnosis was changed in 20/171 (12%) of tumours. Within the clinical cohort, there were 21/95 (22%) patients identified with higher-risk histological subtype tumours. These were associated with tumour invasiveness (P = 0.050), early recurrence (12-24 months, P = 0.013), shorter median time to recurrence (49 (IQR: 22.5-73.0) vs 15 (IQR: 12.0-25.0) months, P = 0.005) and reduced recurrence-free survival (P = 0.031). CONCLUSIONS: Application of transcription factor analysis, in addition to hormone immunohistochemistry, allows for refined pituitary tumour classification and may facilitate an improved approach to prognostication.

Case Report: A Case of Pituitary Carcinoma Treated With Sequential Dual Immunotherapy and Vascular Endothelial Growth Factor Inhibition Therapy.

Aggressive pituitary tumors (APTs) are associated with significant morbidity and mortality, and effective treatment options are limited. Immune checkpoint inhibitors (ICIs) have revolutionized clinical cancer care; however, there is little experience with these agents in the management of APTs. Vascular endothelial growth factor (VEGF) targeted therapy has reported success in a small number of APT case reports. Here we describe a case of pituitary carcinoma responding to ICI therapy and subsequently VEGF inhibition. We discuss the possible mechanisms and experience with ICI therapy and VEGF inhibitors in the management of APTs, biomarkers that may predict response, and the potential role of combination therapies including ICIs and temozolomide.

Exploring the Role of Novel Medical Therapies for Aggressive Pituitary Tumors: A Review of the Literature-"Are We There Yet?"

Aggressive pituitary tumors account for up to 10% of pituitary tumors and are characterized by resistance to medical treatment and multiple recurrences despite standard therapies, including surgery, radiotherapy, and chemotherapy. They are associated with increased morbidity and mortality, particularly pituitary carcinomas, which have mortality rates of up to 66% at 1 year after diagnosis. Novel targeted therapies under investigation include mammalian target of rapamycin (mTOR), tyrosine kinase, and vascular endothelial growth factor (VEGF) inhibitors. More recently, immune checkpoint inhibitors have been proposed as a potential treatment option for pituitary tumors. An increased understanding of the molecular pathogenesis of aggressive pituitary tumors is required to identify potential biomarkers and therapeutic targets. This review discusses novel approaches to the management of aggressive pituitary tumors and the role of molecular profiling.

MANAGEMENT OF ENDOCRINE DISEASE: Does gender matter in the management of acromegaly?

Gonadal steroids modulate the effects of GH, with oestrogens attenuating and androgens augmenting GH action. Whether these divergent effects influence the clinical manifestation, management and prognosis of acromegaly have not been carefully reviewed. This review examines whether there is a gender difference in epidemiology, presentation, quality of life (QoL), morbidity, treatments and mortality of acromegaly. Acromegaly is more common in women who present at an older age with longer diagnostic delay. At presentation, women have a higher GH relative to IGF-1 level than men. QoL is more adversely affected in women both before and after treatment. Prevalence of hypertension and diabetes are greater in women than in men with acromegaly. Treatment outcomes with SSAs are comparable between sexes, but women may require a higher dose of pegvisomant for equivalent response. Mortality in untreated acromegaly is more profoundly affected in women; however, improved treatments in recent decades have resulted in normalisation of standard mortality ratios in both sexes. We conclude that gender does matter in the management of acromegaly, with women presenting later in life, with greater diagnostic delay, higher prevalence of comorbidities and experiencing worse QoL.

Impulse Control Disorders in Dopamine Agonist-Treated Hyperprolactinemia: Prevalence and Risk Factors.

CONTEXT: There are growing reports of dopamine agonist (DA)-induced impulse control disorders (ICDs) in hyperprolactinemic patients. However, the magnitude of this risk and predictive factors remain uncertain. OBJECTIVE: To determine ICD prevalence and risk factors in DA-treated hyperprolactinemic patients compared to community controls. DESIGN, SETTING AND PARTICIPANTS: Multicenter cross-sectional analysis of 113 patients and 99 healthy controls. MAIN OUTCOME MEASURES: Participants completed a neuropsychological questionnaire consisting of the Depression Anxiety Stress Scale (DASS21), Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease (QUIP-S), Hypersexual Behavior Inventory (HBI), Hypersexual Behavior Consequences Scale and Social Desirability Response Set Scale. Demographic and clinical data were collated to determine ICD risk factors. Patients testing positive for an ICD were offered a semistructured psychological interview. RESULTS: Patients were more likely than controls to test positive by QUIP-S for any ICD (61.1 vs 42.4%, P = .01), hypersexuality (22.1 vs 8.1%, P = .009), compulsive buying (15.9 vs 6.1%, P = .041) and punding (18.6 vs 6.1%, P = 0.012), and by HBI for hypersexuality (8.0 vs 0.0%, P = 0.004). Independent risk factors were male sex (odds ratio [OR] 13.85), eugonadism (OR 7.85), Hardy's tumor score and psychiatric comorbidity (OR 6.86) for hypersexuality, and age (OR 0.95) for compulsive buying. DASS21 subset scores were higher in patients vs controls and in patients with vs without different ICDs. Only 19/51 (37.3%) interviewed patients were aware of the relationship between DAs and ICDs before the study. CONCLUSIONS: DA therapy poses a high, previously underestimated risk of ICDs, especially in the form of hypersexuality in eugonadal men.

Low O6-methylguanine-DNA methyltransferase (MGMT) expression and response to temozolomide in aggressive pituitary tumours.

CONTEXT: Recent case reports detail the successful use of temozolomide in the management of aggressive pituitary tumours. O(6)-methylguanine-DNA methyltransferase (MGMT) is a DNA repair protein that counteracts the effect of temozolomide. OBJECTIVE: To study MGMT expression in pituitary tumours and consider whether MGMT expression is associated with response to temozolomide therapy in aggressive pituitary tumours. PATIENTS: We report two patients with aggressive pituitary tumours treated with temozolomide, one who responded to temozolomide and the other who did not. MGMT expression was assessed in a further 88 archived pituitary tumour samples. DESIGN: MGMT expression was assessed by immunohistochemistry. MGMT promoter methylation was studied by methylation-specific polymerase chain reaction (MSP), sequencing of MGMT was performed and loss of heterozygosity (LOH) analysis undertaken. RESULTS: Low MGMT expression and MGMT promoter methylation were found in the pituitary tumour of the patient who responded to temozolomide. Conversely, high MGMT expression was seen in the patient demonstrating a poor response to temozolomide. Eleven out of 88 archived tumour samples (13%) had low MGMT expression. Prolactinomas were more likely to have low MGMT expression compared with other pituitary tumour subtypes (P < 0.001). There was no significant difference in MGMT expression between invasive and noninvasive tumours, or between recurrent and nonrecurrent tumours. A significant inverse correlation was found between MGMT expression and promoter methylation (P = 0.012). CONCLUSION: MGMT expression as assessed by immunohistochemistry may predict response to temozolomide therapy in patients with aggressive pituitary tumours. MGMT promoter methylation is likely to explain low MGMT expression in some, but not all, pituitary tumours.