Management of pituitary incidentalomas. A survey of British and American endocrinologists

UK practice on incidentally detected non-functioning pituitary microadenomas: analysis of two national surveys during a 12-year interval

PURPOSE

The optimal management approach for presumed non-functioning pituitary microadenomas (microNFPAs) remains unclear. Our aim was to capture current UK practice and identify changes with time.

METHODS

Two online surveys investigating clinicians' approaches were performed in 2009-2010 and 2021-2022 (advertised through Society for Endocrinology UK).

RESULTS

150 and 214 clinicians participated in the 2021 and 2009 survey, respectively (response rates 31.2% and 35.4%, respectively). At baseline, 2021 survey respondents were more likely to measure IGF-1 (96.0% vs 74.1%, p < 0.001) and morning cortisol (87.9% vs 62.6%, p < 0.001), and less likely GH (26.2% vs 42.6% p = 0.002), 24 h urine free cortisol (3.4% vs 23.2%, p < 0.0001) or dynamically assess adrenal reserve (11.4% vs 30.4%, p < 0.001). 47.2% of clinicians in 2021 would reassess pituitary function annually until discharge (in absence of tumour growth/symptoms). The 2021 survey respondents were more likely to stop imaging at or before 3 years (81.7% vs 44.3%, p < 0.001) and at or before 5 years (86.6.% vs 72.9%, p = 0.002), whilst 2009 survey respondents were more likely to continue imaging beyond 5 years (24% vs 7%, p < 0.001). Responses on imaging frequency/intervals showed notable variability in both surveys.

CONCLUSIONS

Diagnostic and management approaches for microNFPAs have evolved in the UK. Biochemical investigations are performed in accord with consensus guidelines, though many clinicians perform annual biochemical surveillance without tumour growth/symptoms. A small number of clinicians request imaging beyond 5 years, but the frequency of imaging intervals until discharge remains variable. Robust evidence on the long-term natural history of microNFPAs is necessary to unify clinician approach.

Pituitary incidentaloma

Pituitary incidentalomas (PI) are lesions of the pituitary region discovered fortuitously by imaging for reasons unrelated to pituitary disease. They range from small cysts to large invasive adenomas. All over the world, improvements in the quality and availability of radiological examinations are leading to an increase in the discovery of PI. In the last four decades, significant advances have been made in the understanding of PI. Autopsy studies have shown that about 10% of deceased individuals harbour a PI, most often a non-functioning microadenoma. In contrast, modern patient series showed that among PIs that come to endocrinological attention, a significant proportion are macroadenomas, and many patients suffer from asymptomatic or pauci-symptomatic endocrine or ophthalmologic disturbances. Other than adenomas, empty sella, Rathke's cleft cyst, craniopharyngioma and meningioma are the most frequent types of PIs. About 10% of micro-incidentalomas and 25% of macro-incidentalomas grow over time. Most cases can be managed conservatively by mere surveillance. Follow-up is necessary in all patients with macroadenoma, but uncertainty remains for microadenomas as to the extent of endocrinological work-up as well as the necessity and duration of follow-up. Visual and endocrine anomalies constitute the most common indications for surgery. When needed, surgery yields better outcome in PIs than in symptomatic pituitary lesions.

Pituitary incidentalomas

INTRODUCTION

Incidentally discovered pituitary adenomas are more and more commonly encountered in endocrinology and neurosurgical practices. Often they present as difficult problems in management strategies. This review summarizes the latest evidence and opinions in a variety of settings in which incidental pituitary tumors are discovered, including subclinical pituitary tumor apoplexy.

METHODS

A systematic literature review was accomplished using a spectrum of contemporary sources for information regarding pituitary incidentalomas.

RESULTS

Up to date findings regarding epidemiology, definition of pituitary incidentaloma, patient evaluation, diagnostic studies, and management are presented.

CONCLUSIONS

Current experience from a multidisciplinary pituitary center is presented, with indications for treatment and longitudinal care of these challenging patients.

Pituitary incidentalomas: application of an evidence-based approach at the individual patient and population levels

With the widespread use of imaging techniques, incidental discovery of clinically unsuspected pituitary adenomas is increasing in frequency and will increase further. The Endocrine Society Task Force on Pituitary Incidentalomas has developed practice guidelines which reflect the best available evidence combined with the opinions of experts in pituitary diseases. For incidental macroadenomas, evidence supporting comprehensive evaluation (for hyperfunction, hypopituitarism and anatomy) and management (whether surgical or careful follow-up) is strong. By contrast, evidence supporting approaches to microadenomas without clinical suggestion of hormonal hypersecretion are relatively weak and practice varies. Developing more evidence will require approaches other than randomized controlled trials, such as comparative effectiveness studies. Incidentalomas represent part of a larger societal issue, that being overdiagnosis and its consequences.

Evidence-based endocrinology: illustrating its principles in the management of patients with pituitary incidentalomas

Incidentally discovered pituitary lesions are commonly encountered in the current era of ever-increasing imaging. Individualizing a particular approach implies a thorough analysis of existing evidence and balancing it against different patient expectations. We will illustrate the application of principles of Evidence-Based Medicine to a case of a pituitary incidentaloma by formulating questions that are important to patient care and finding related evidence. Our objective is to reflect the opportunities and the challenges that an evidence-based clinical approach offers to clinicians and patients.

Incidentally discovered pituitary masses: pituitary incidentalomas

With the widespread use of computed tomography and MRI, the incidental discovery of pituitary incidentalomas is increasing in frequency. The most common cause of a pituitary mass is a pituitary adenoma (90% of all pituitary masses); however, the differential diagnosis remains extensive. The challenge is to distinguish those that can or will cause morbidity/mortality from those that will not. Opinions on approaching management of these lesions vary. This article will review current data regarding the prevalence, natural history and potential morbidity associated with this entity and describe an epidemiological approach based on four questions: does an incidental mass put the patient at increased risk for an adverse outcome? Can individuals with treatable syndromes be accurately diagnosed? Is the treatment of these syndromes more effective in presymptomatic patients? And do the beneficial effects of presymptomatic detection and treatment of these patients justify the costs incurred? We recommend the following approach: recognizing that one size does not fit all and that the approach should be tailored to the needs of the particular case. If the mass was discovered on a computed tomography, an enhanced MRI is recommended. Detailed history and physical examination should be carried out to look for signs of functional or 'subclinically' functional tumor. Size and structure should be assessed, especially proximity to the optic chiasm. Laboratory evaluation with a serum prolactin for small tumors is cost effective, other lab testing is indicated if metabolic problems are present. Care should be taken to assess for hypopituitarism, clinically and biochemically, if the mass is large, that is, more than 1 cm, visual field testing is also recommended. Note that the vast majority of patients with pituitary incidentalomas that are microadenomas die with them, not from them.

Pituitary incidentalomas--how often is too often?

INTRODUCTION

Clinical nonfunctional pituitary microadenomas, also known as incidentalomas are accidental observations made due to the application of high resolution imaging techniques as computed tomography or magnetic resonance. There are no standards regarding the follow-up of these tumors and taking into account their increased frequency among general population (during the last years they were based on the high performances of the imaging methods), we decided to study their dimensions and their evolution over time. We have also analysed their behavior with respect to their endocrine phenotype and the minimum period of time needed for the repetition of the imagistic procedure.

AIM

To observe the natural evolution of tumors' dimensions in a group of patients, diagnosed with nonfunctional pituitary microadenomas based upon hormonal measurements and computed tomography scan.

METHOD

There is a retrospective observational study on 149 patients hospitalized in our Clinic between 1994 and 2006. Initially, all the pituitary hormones and the computed tomography were performed. Only nonfunctional microadenomas were included (the maximum diameter 11 mm). 69 patients were examined for a long period of time--29.75 +/- 24.79 months by CT scan and secretory profile, repeated at different periods of time.

RESULTS

At the end of 29.75 months, the aspect of microadenoma was still present, without any statistically significant changes of the diameter. One of the cases became macroadenoma and another proved to be a microprolactinoma. Only 5 cases of all 149 presented a double lesion. No case of pituitary apoplexy was registered. These observations lead to the conclusion that it is not necessary to repeat the computed tomography scan sooner than 2 years once the diagnosis ofincidentaloma was established.

Evaluation and management of pituitary incidentalomas--revisiting an acquaintance

Incidentalomas of the pituitary gland have been described with increasing frequency, paralleling the advances in diagnostic imaging modalities. Several approaches have been proposed in order to appropriately evaluate their impact on patients, some recommending extensive investigations, while others advocate a more focused and potentially more cost-effective approach. The first part of this article will review current data about the prevalence, natural history and potential morbidity associated with these tumors. The second part will focus on imaging and hormonal evaluation of the incidental mass and suggest an updated management algorithm.

Incidentalomas hipofisários

Lesões hipofisárias clinicamente inaparentes são demonstradas através da ressonância magnética em aproximadamente 10% da população geral adulta, caracterizando os chamados incidentalomas hipofisários. A história natural dessas lesões ainda não está completamente estabelecida. Embora sejam tipicamente pequenos (< 10mm no seu maior diâmetro) e clinicamente silenciosos, alguns incidentalomas hipofisários podem secretar hormônios ou causar efeitos de massa por compressão sobre estruturas vizinhas. Além disso, uma minoria dessas lesões, principalmente aquelas com mais de 10mm (macroincidentalomas) podem crescer com o tempo; assim, o seguimento a longo prazo se faz necessário. Intervenções terapêuticas estão indicadas para os incidentalomas funcionantes (uso de agonistas dopaminérgicos ou ressecção transesfenoidal) ou para aqueles que causem efeitos de massa ou aumentem de tamanho durante o seguimento (ressecção transesfenoidal). Significante extensão supra-selar ou hipopituitarismo podem ser indicações adicionais para o tratamento cirúrgico, mesmo na ausência de compressão quiasmática.

Diagnostic and Therapeutic Approach to Pituitary Incidentalomas

OBJECTIVE

To review data on epidemiology, differential diagnosis, clinical, laboratory, and imaging findings, natural history, and management of incidentally discovered pituitary lesions (pituitary incidentalomas).

METHODS

A nonsystematic review was conducted, including articles indexed in Index Medicus that contained reference to incidentally discovered pituitary masses (pituitary incidentalomas).

RESULTS

Both autopsy and sensitive neuroimaging studies (including magnetic resonance imaging) suggest that pituitary incidentalomas are common, affecting approximately 10% of the general population. Although typically small (less than 10 mm in greatest diameter) and clinically silent, some pituitary incidentalomas may be hormonally active or cause mass effects by compressing neighboring structures. In addition, a minority of these lesions may grow over time; hence, long-term follow-up is necessary. Therapeutic interventions, including dopamine agonist therapy (in the case of prolactin-secreting adenomas) or transsphenoidal resection, are indicated in the case of pituitary lesions that are hormonally active, cause mass effects, or increase in size.

CONCLUSION

Pituitary incidentalomas are common and constitute a heterogeneous group with regard to pathologic features, clinical, laboratory, and imaging characteristics, natural history, and growth potential. Currently available evidence suggests that many hormonally nonfunctioning pituitary incidentalomas causing no mass effects can be safely managed by follow-up surveillance. Nonetheless, more data are needed for further elucidation of the natural history of these lesions and for improvement in accurate and noninvasive diagnosis and in prediction of growth potential of pituitary incidentalomas. Improved understanding of the pathogenesis of this heterogeneous group of lesions may also lead to the development of novel, noninvasive therapeutic agents, rationally designed to interact with well-characterized molecular targets.

Pituitary tumor diagnosis and treatment

Over the past few years, significant contributions have been made to the understanding, diagnosis, and treatment of pituitary tumors. This article reviews recent advances in the areas of biology, diagnostic imaging, medical diagnosis and treatment, surgical results and technique, and adjuvant therapy in the form of radiotherapy and radiosurgery. Of particular note are the roles of endoscopy, intraoperative magnetic resonance imaging, radiosurgery, and radiation for nonfunction tumors, the diagnosis of Cushing's disease, the management of "incidentalomas," and new medication therapies.