Aggressive pituitary tumours and carcinomas, characteristics and management of 171 patients.

Objective: To describe clinical and pathological characteristics and treatment outcomes in a large cohort of aggressive pituitary tumours (APT)/pituitary carcinomas (PC).

Design: Electronic survey August 2020-May 2021.

Results: 96% of 171 (121 APT, 50 PC), initially presented as macro/giant tumours, 6 were microadenomas (5 corticotroph).

Aggressive pituitary tumours and pituitary carcinomas.

Although usually benign, anterior pituitary tumours occasionally exhibit aggressive behaviour, with invasion of surrounding tissues, rapid growth, resistance to conventional treatments and multiple recurrences. In very rare cases, they metastasize and are termed pituitary carcinomas. The time between a 'classical' pituitary tumour and a pituitary carcinoma can be years, which means that monitoring should be performed regularly in patients with clinical (invasion and/or tumour growth) or pathological (Ki67 index, mitotic count and/or p53 detection) markers suggesting aggressiveness.

GHRH secretion from a pancreatic neuroendocrine tumor causing gigantism in a patient with MEN1.

Summary: A male patient with a germline mutation in MEN1 presented at the age of 18 with classical features of gigantism. Previously, he had undergone resection of an insulin-secreting pancreatic neuroendocrine tumour (pNET) at the age of 10 years and had subtotal parathyroidectomy due to primary hyperparathyroidism at the age of 15 years. He was found to have significantly elevated serum IGF-1, GH, GHRH and calcitonin levels.

How to Classify the Pituitary Neuroendocrine Tumors (PitNET)s in 2020.

Adenohypophyseal tumors, which were recently renamed pituitary neuroendocrine tumors (PitNET), are mostly benign, but may present various behaviors: invasive, "aggressive" and malignant with metastases. They are classified into seven morphofunctional types and three lineages: lactotroph, somatotroph and thyrotroph (PIT1 lineage), corticotroph (TPIT lineage) or gonadotroph (SF1 lineage), null cell or immunonegative tumor and plurihormonal tumors. The WHO 2017 classification suggested that subtypes, such as male lactotroph, silent corticotroph and Crooke cell, sparsely granulated somatotroph, and silent plurihormonal PIT1 positive tumors, should be considered as "high risk" tumors.

A standardised diagnostic approach to pituitary neuroendocrine tumours (PitNETs): a European Pituitary Pathology Group (EPPG) proposal.

The 2017 World Health Organization (WHO) classification proposes to type and subtype primary adenohypophyseal tumours according to their cell lineages with the aim to establish more uniform tumour groups. The definition of atypical adenoma was removed in favour of high-risk adenoma, and the assessment of proliferative activity and invasion was recommended to diagnose aggressive tumours. Recently, the International Pituitary Pathology Club proposed to replace adenoma with the term of pituitary neuroendocrine tumour (PitNET) to better reflect the similarities between adenohypophyseal and neuroendocrine tumours of other organs.

Diagnosis, pathology, and management of TSH-secreting pituitary tumors. A single-center retrospective study of 20 patients from 1981 to 2014.

TSH (thyroid-stimulating hormone)-secreting tumors are the rarest type of pituitary tumor. The objective of this study was to describe initial presentation and follow-up in patients presenting TSH-secreting tumors and to characterize the pathological features, based on a cohort of 20 patients treated in our referral center, between 1981 and 2014. Most of the patients (75%) were female, aged around 50 years (mean: 50±13 years).

Three Consecutive Pregnancies in a Patient with Chronic Autoimmune Thyroid Disease Associated with Hypothyroidism and Extremely High Levels of Anti-Thyrotropin Receptor Antibodies.

Thyroid-stimulating hormone (TSH) receptor (TSHR) antibodies (TRAb) can be present in chronic autoimmune thyroiditis. Transplacental TRAb transfer can lead to fetal thyroid dysfunction and serious complications. We report the case of a woman with autoimmune hypothyroidism and extremely high TRAb levels, with blocking and stimulating activities (biological activities characterized with Chinese hamster ovary cells expressing TSHR).

Clinical, Pathological, and Molecular Factors of Aggressiveness in Lactotroph Tumours.

The behaviour of lactotroph tumours varies between benign tumours, those cured by treatment, and that of aggressive tumours, and carcinomas with metastasis. Identification of clinical, pathological and molecular factors is essential for the early identification of patients that may have such aggressive tumours. Plasma prolactin levels and tumour size and invasion, per se, are not prognostic factors.

Sex-Related Differences in Lactotroph Tumor Aggressiveness Are Associated With a Specific Gene-Expression Signature and Genome Instability.

Sex-related differences have been reported in various cancers, in particular men with lactotroph tumors have a worse prognosis than women. While the underlying mechanism of this sexual dimorphism remains unclear, it has been suggested that a lower estrogen receptor alpha expression may drive the sex differences observed in aggressive and malignant lactotroph tumors that are resistant to dopamine agonists. Based on this observation, we aimed to explore the molecular importance of the estrogen pathway through a detailed analysis of the transcriptomic profile of lactotroph tumors from 20 men and 10 women.

Pathological markers of somatotroph pituitary neuroendocrine tumors predicting the response to medical treatment.

Acromegaly is mainly due to the somatotroph pituitary neuroendocrine tumors (PitNET)s. These have been subtyped into densely granulated (DG) and sparsely granulated (SG) tumors, which differ in clinical, histological and biological characteristics and in response to somatostatin analogs (SA)s. The variable remission rate after surgical resection, as first line treatment, has increased interest in identifying pathological markers to better predict the response to medical treatment.

A common classification framework for neuroendocrine neoplasms: an International Agency for Research on Cancer (IARC) and World Health Organization (WHO) expert consensus proposal.

The classification of neuroendocrine neoplasms (NENs) differs between organ systems and currently causes considerable confusion. A uniform classification framework for NENs at any anatomical location may reduce inconsistencies and contradictions among the various systems currently in use. The classification suggested here is intended to allow pathologists and clinicians to manage their patients with NENs consistently, while acknowledging organ-specific differences in classification criteria, tumor biology, and prognostic factors.

Aggressive pituitary tumours and carcinomas: two sides of the same coin?

The European Society of Endocrinology (ESE) survey reported on the largest cohort of 125 aggressive pituitary tumours (APT) and 40 pituitary carcinomas (PC). Whilst the survey focused on treatment effectiveness, all pathological data were not explored in detail. Here, we comment on some interesting pathological findings, notably the difference between APT and PC.

Treatment of aggressive pituitary tumours and carcinomas: results of a European Society of Endocrinology (ESE) survey 2016.

Objective: To collect outcome data in a large cohort of patients with aggressive pituitary tumours (APT)/carcinomas (PC) and specifically report effects of temozolomide (TMZ) treatment.

Design: Electronic survey to ESE members Dec 2015-Nov 2016.

Results: Reports on 166 patients (40 PC, 125 APT, 1 unclassified) were obtained.

European Society of Endocrinology Clinical Practice Guidelines for the management of aggressive pituitary tumours and carcinomas.

Background: Pituitary tumours are common and easily treated by surgery or medical treatment in most cases. However, a small subset of pituitary tumours does not respond to standard medical treatment and presents with multiple local recurrences (aggressive pituitary tumours) and in rare occasion with metastases (pituitary carcinoma). The present European Society of Endocrinology (ESE) guideline aims to provide clinical guidance on diagnosis, treatment and follow-up in aggressive pituitary tumours and carcinomas.

Serotonin, ATRX, and DAXX Expression in Pituitary Adenomas: Markers in the Differential Diagnosis of Neuroendocrine Tumors of the Sellar Region.

Differential diagnosis based on morphology and immunohistochemistry between a clinically nonfunctioning pituitary neuroendocrine tumor (NET)/pituitary adenoma and a primary or secondary NET of nonpituitary origin in the sellar region may be difficult. Serotonin, a frequently expressed marker in the NETs, has not been systematically evaluated in pituitary NETs. Although mutations in ATRX or DAXX have been reported in a significant proportion of pancreatic NETs, the mutational status of ATRX and DAXX and their possible pathogenetic role in pituitary NETs are unknown.

Risks and Benefits of Endoscopic Transsphenoidal Surgery for Nonfunctioning Pituitary Adenomas in Patients of the Ninth Decade.

Background: The population older than 80 years of age (very elderly) is increasing, and the management of these patients with pituitary surgery is controversial.

Objective: To determine the prevalence of pituitary tumors in elderly patients and to determine the safety of endoscopic transsphenoidal pituitary surgery for nonfunctioning pituitary adenomas in patients aged older than 80 years.

Methods: This retrospective study included elderly (65-75 years old) and very elderly consecutive patients operated between 2007 and 2015 for nonfunctioning pituitary adenomas.

Risk of Recurrence in Pituitary Neuroendocrine Tumors: A Prospective Study Using a Five-Tiered Classification.

Background: Most pituitary neuroendocrine tumors (PitNETs) show benign behavior, but a substantial number are invasive, recur, or resist medical treatment. Based on a retrospective case-control study, we recently proposed a classification of PitNETs of prognostic relevance. This prospective study aims to test the value of this classification in an independent patient cohort.

From pituitary adenoma to pituitary neuroendocrine tumor (PitNET): an International Pituitary Pathology Club proposal.

The classification of neoplasms of adenohypophysial cells is misleading because of the simplistic distinction between adenoma and carcinoma, based solely on metastatic spread and the poor reproducibility and predictive value of the definition of atypical adenomas based on the detection of mitoses or expression of Ki-67 or p53. In addition, the current classification of neoplasms of the anterior pituitary does not accurately reflect the clinical spectrum of behavior. Invasion and regrowth of proliferative lesions and persistence of hormone hypersecretion cause significant morbidity and mortality.

MicroRNAs in pituitary tumors.

Since the presence of microRNAs was first observed in normal pituitary, the majority of scientific publications addressing their role and the function of microRNAs in the pituitary have been based on pituitary tumor studies. In this review, we briefly describe the involvement of microRNAs in the synthesis of pituitary hormones and we present a comprehensive inventory of microRNA suppressors and inducers of pituitary tumors. Finally, we summarize the functional role of microRNAs in tumorigenesis, progression and aggressiveness of pituitary tumors, mechanisms contributing to the regulation (transcription factors, genomic modifications or epigenetic) or modulation (pharmacological treatment) of microRNAs in these tumors, and the interest of thoroughly studying the expression of miRNAs in body fluids.