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CNS Neuroscience & Therapeutics May 2024Pituitary adenoma is one of the most common brain tumors. Most pituitary adenomas are benign and can be cured by surgery and/or medication. However, some pituitary... (Review)
Review
BACKGROUND
Pituitary adenoma is one of the most common brain tumors. Most pituitary adenomas are benign and can be cured by surgery and/or medication. However, some pituitary adenomas show aggressive growth with a fast growth rate and are resistant to conventional treatments such as surgery, drug therapy, and radiation therapy. These tumors, referred to as refractory pituitary adenomas, often relapse or regrow in the early postoperative period. The tumor microenvironment (TME) has recently been identified as an important factor affecting the biological manifestations of tumors and acts as the main battlefield between the tumor and the host immune system.
MAIN BODY
In this review, we focus on describing TME in pituitary adenomas and refractory pituitary adenomas. Research on the immune microenvironment of pituitary adenomas is currently focused on immune cells such as macrophages and lymphocytes, and extensive research and experimental verifications are still required regarding other components of the TME. In particular, studies are needed to determine the role of the TME in the specific biological behaviors of refractory pituitary adenomas, such as high invasion, fast recurrence rate, and high tolerance to traditional treatments and to identify the mechanisms involved.
CONCLUSION
Overall, we summarize the similarities and differences between the TME of pituitary adenomas and refractory pituitary adenomas as well as the changes in the biological behavior of pituitary adenomas that may be caused by the microenvironment. These changes greatly affect the outcome of patients.
Topics: Pituitary Neoplasms; Humans; Tumor Microenvironment; Adenoma; Animals; Treatment Outcome
PubMed: 38738958
DOI: 10.1111/cns.14729 -
Frontiers in Endocrinology 2020Pituitary adenomas, accounting for 15% of diagnosed intracranial neoplasms, are usually benign and pharmacologically and surgically treatable; however, the critical... (Review)
Review
Pituitary adenomas, accounting for 15% of diagnosed intracranial neoplasms, are usually benign and pharmacologically and surgically treatable; however, the critical location, mass effects and hormone hypersecretion sustain their significant morbidity. Approximately 35% of pituitary tumors show a less benign course since they are highly proliferative and invasive, poorly resectable, and likely recurring. The latest WHO classification of pituitary tumors includes pituitary transcription factor assessment to determine adenohypophysis cell lineages and accurate designation of adenomas, nevertheless little is known about molecular and cellular pathways which contribute to pituitary tumorigenesis. In malignant tumors the identification of cancer stem cells radically changed the concepts of both tumorigenesis and pharmacological approaches. Cancer stem cells are defined as a subset of undifferentiated transformed cells from which the bulk of cancer cells populating a tumor mass is generated. These cells are able to self-renew, promoting tumor progression and recurrence of malignant tumors, also conferring cytotoxic drug resistance. On the other hand, the existence of stem cells within benign tumors is still debated. The presence of adult stem cells in human and murine pituitaries where they sustain the high plasticity of hormone-producing cells, allowed the hypothesis that putative tumor stem cells might exist in pituitary adenomas, reinforcing the concept that the cancer stem cell model could also be applied to pituitary tumorigenesis. In the last few years, the isolation and phenotypic characterization of putative pituitary adenoma stem-like cells was performed using a wide and heterogeneous variety of experimental models and techniques, although the role of these cells in adenoma initiation and progression is still not completely definite. The assessment of possible pituitary adenoma-initiating cell population would be of extreme relevance to better understand pituitary tumor biology and to identify novel potential diagnostic markers and pharmacological targets. In this review, we summarize the most updated studies focused on the definition of pituitary adenoma stem cell phenotype and functional features, highlighting the biological processes and intracellular pathways potentially involved in driving tumor growth, relapse, and therapy resistance.
Topics: Adenoma; Animals; Cell Transformation, Neoplastic; Drug Resistance, Neoplasm; Humans; Neoplasm Recurrence, Local; Neoplastic Stem Cells; Pituitary Neoplasms
PubMed: 32153500
DOI: 10.3389/fendo.2020.00054 -
Frontiers in Endocrinology 2021Pituitary tumors are very complex and heterogeneous and have a very wide range of proliferative and aggressive behaviors, and how to define and classify these tumors... (Review)
Review
Pituitary tumors are very complex and heterogeneous and have a very wide range of proliferative and aggressive behaviors, and how to define and classify these tumors remains controversial. This review summarizes the epidemiology and progress in the classification and definition of pituitary tumors, as well as controversial issues. Based on the results of radiologic and autopsy studies, the prevalence of pituitary tumors has recently increased significantly. However, the majority of pituitary tumors are incidentally discovered and asymptomatic, and such tumors are called pituitary incidentalomas. Most of these incidentalomas do not induce symptoms, remain stable in size, and do not need treatment. The recent revised classification strategies mainly depend on immunohistochemistry (IHC) to detect pituitary hormones and pituitary transcription factors; therefore, the accuracy of diagnosing pituitary tumors has improved. Although new classification strategies and definitions for pituitary tumors have been presented, there are still some controversies. The term pituitary neuroendocrine tumor (PitNET) was proposed by the International Pituitary Pathology Club, and this terminology can encompass the unpredictable malignant behavior seen in the subset of aggressive pituitary adenomas (PAs). However, some endocrinologists who oppose this change in terminology have argued that the use of tumor in the terminology is misleading, as it gives PAs a harmful connotation when the majority are not aggressive. Such terminology may add new ambiguity to the origin of PAs and unnecessary anxiety and frustration for the majority of patients with benign PAs. The classification of aggressive PAs mainly relies on subjective judgment of clinical behavior and lacks objective biomarkers and unified diagnostic criteria. However, the term "refractory" could more accurately represent the characteristics of these tumors, including their clinical behaviors, radiological features, and pathologic characteristics. Moreover, the diagnostic criteria for refractory PAs are stricter, more objective, and more accurate than those for aggressive PAs. Early identification of patients with these tumors through recognition and increased awareness of the definition of refractory PAs will encourage the early use of aggressive therapeutic strategies.
Topics: Adenoma; Diagnostic Techniques, Endocrine; Humans; Neuroendocrine Tumors; Pituitary Neoplasms; Practice Guidelines as Topic
PubMed: 33815274
DOI: 10.3389/fendo.2021.604644 -
Clinical Neurology and Neurosurgery Feb 2024Pituitary adenomas are slow-growing, benign intracranial tumors that can be characterized as functional (hormone-producing) or non-functional (non-hormone producing).... (Review)
Review
Pituitary adenomas are slow-growing, benign intracranial tumors that can be characterized as functional (hormone-producing) or non-functional (non-hormone producing). Symptoms therefore arise from either endocrinologic abnormalities or mass effect on surrounding structures resulting in symptoms such as visual impairment and headache. In the last two decades, technical innovations have shifted surgical resection of such adenomas to endoscopic endonasal approaches. In this review, we describe the evolving approach to pituitary adenomas in the modern endoscopic era, including preoperative multidisciplinary review, relevant surgical anatomy, and a description of the technical nuances of standard and expanded approaches to the anterior skull base.
Topics: Humans; Pituitary Neoplasms; Endoscopy; Adenoma; Brain Neoplasms; Headache
PubMed: 38359520
DOI: 10.1016/j.clineuro.2024.108172 -
Orvosi Hetilap Mar 2020Thyrotropin-secreting pituitary tumors are rare causes of hyperthyroidism and account for less than 1% of all pituitary adenomas. The number of reported cases increased...
Thyrotropin-secreting pituitary tumors are rare causes of hyperthyroidism and account for less than 1% of all pituitary adenomas. The number of reported cases increased over the last few years as a consequence of the routine use of ultrasensitive immunometric assays for measuring thyrotropin levels. In the clinical practice, thyrotropin secreting adenomas must be considered in case of inappropriately normal to elevated thyrotropin in the presence of elevated free serum thyroid hormone levels. The authors present the case history of a middle aged female patient, who suffered from hyperthyreodism caused by a thyrotropin-secreting pituitary macroadenoma. After transient thyreostatic treatment, radical neurosurgical removal of the tumor was performed. The pituitary surgery was effective in restoring the patient's euthyreodism. The postoperative pituitary function remained intact. During follow-up, the recurrence of the disease was not detected. In our case report, the difficulties in the differential diagnoses are also discussed. Orv Hetil. 2020; 161(12): 474-478.
Topics: Adenoma; Female; Humans; Hyperthyroidism; Middle Aged; Neoplasm Recurrence, Local; Pituitary Neoplasms; Thyroid Function Tests; Thyrotropin; Treatment Outcome
PubMed: 32172585
DOI: 10.1556/650.2020.31697 -
Journal of Endocrinological... Dec 2019Thyrotropin-secreting pituitary adenomas (TSH-omas) present with signs and symptoms of hyperthyroidism and they are characterized by elevated serum levels of free... (Review)
Review
Thyrotropin-secreting pituitary adenomas (TSH-omas) present with signs and symptoms of hyperthyroidism and they are characterized by elevated serum levels of free thyroid hormones with measurable TSH levels. TSH-omas are very infrequent, accounting for less than 1% of all pituitary adenomas, thus representing a very rare cause of hyperthyroidism. For this reason, data collected on these rare disorders are relatively few, but some new researches shed new light on the etiopathogenesis, the diagnosis and the treatment of such a remarkable disease. Since the same biochemical picture is present in the syndromes of thyroid hormone resistance (RTH), in particular in the form of pituitary RTH, failure in distinguishing these clinical entities may lead to improper patient management. Conversely, early diagnosis and correct treatment of TSH-omas may prevent the occurrence of neurological and endocrinological complications, thus leading to a better rate of cure. In the present short review article, the most relevant recent advances in the pathophysiology of TSH-omas are described.
Topics: Adenoma; Humans; Hyperthyroidism; Pituitary Neoplasms; Thyroid Hormones; Thyrotropin
PubMed: 31175617
DOI: 10.1007/s40618-019-01066-x -
Mayo Clinic Proceedings Oct 2022To perform a population-based study of pituitary adenoma epidemiology, including longitudinal trends in disease incidence, treatment patterns, and outcomes.
OBJECTIVE
To perform a population-based study of pituitary adenoma epidemiology, including longitudinal trends in disease incidence, treatment patterns, and outcomes.
PATIENTS AND METHODS
In this study of incident pituitary adenomas in Olmsted County, Minnesota, from January 1, 1989, through December 31, 2019, we identified 785 patients who underwent primary screening, 435 of whom were confirmed as harboring incident pituitary adenomas and were included. Primary outcomes of interest included demographic characteristics, presenting features, and disease outcomes (tumor control, biochemical control, and complications).
RESULTS
Among our 435 study patients, 438 unique pituitary adenomas were diagnosed at a median patient age of 39 years (interquartile range [IQR], 27 to 58 years). Adenomas were incidentally identified in 164 of the 438 tumors (37%). Common symptomatic presentations included hyperprolactinemia (188 of 438 [43%]) and visual field deficit (47 of 438 [11%]). Laboratory tests confirmed pituitary hormone hypersecretion in 238 of the 435 patients (55%), which was symptomatic in 222. The median tumor diameter was 8 mm (IQR, 5 to 17 mm). Primary management strategies were observation (156 of 438 tumors [36%]), medication (162 of 438 tumors [37%]), and transsphenoidal resection (120 of 438 tumors [27%]). Tumor and biochemical control were achieved in 398 (95%) and 216 (91%) secreting tumors, respectively. New posttreatment pituitary or visual deficits were noted in 43 (11%) and 8 (2%); apoplexy occurred in 28 (6%). Median clinical follow-up was 98 months (IQR, 47 to 189 months). Standardized incidence rates were 3.77 to 16.87 per 100,000 population, demonstrating linear expansion over time (R=0.67). The mean overall standardized incidence rate was 10.1 per 100,000 population; final point prevalence was 175.1 per 100,000 population.
CONCLUSION
Pituitary adenoma is a highly incident disease, with prolactin-secreting and incidental lesions representing the majority of tumors. Incidence rates and asymptomatic detection appear to be increasing over time. Presenting symptoms and treatment pathways are variable; however, most patients achieve favorable outcomes with observation or a single treatment modality.
Topics: Adenoma; Adult; Humans; Incidence; Middle Aged; Pituitary Hormones; Pituitary Neoplasms; Prolactin; Retrospective Studies; Treatment Outcome
PubMed: 35753823
DOI: 10.1016/j.mayocp.2022.03.017 -
Endocrinology and Metabolism Clinics of... Sep 2020In most patients with pituitary adenomas magnetic resonance imaging (MRI) is essential to guide effective decision-making. T1- and T2-weighted sequences allow the... (Review)
Review
In most patients with pituitary adenomas magnetic resonance imaging (MRI) is essential to guide effective decision-making. T1- and T2-weighted sequences allow the majority of adenomas to be readily identified. Supplementary MR sequences (e.g. FLAIR; MR angiography) may also help inform surgery. However, in some patients MRI findings are 'negative' or equivocal (e.g. with failure to reliably identify a microadenoma or to distinguish postoperative change from residual/recurrent disease). Molecular imaging [e.g. C-methionine PET/CT coregistered with volumetric MRI (Met-PET/MR)] may allow accurate localisation of the site of de novo or persistent disease to guide definitive treatment (e.g. surgery or radiosurgery).
Topics: Diagnostic Imaging; Endocrinology; Humans; Medical Oncology; Pituitary Neoplasms
PubMed: 32741476
DOI: 10.1016/j.ecl.2020.06.002 -
AJNR. American Journal of Neuroradiology Sep 2022Granulomatous hypophysitis is a rare inflammatory condition of the pituitary gland with an imaging appearance that can overlap with that of pituitary adenoma.... (Review)
Review
BACKGROUND AND PURPOSE
Granulomatous hypophysitis is a rare inflammatory condition of the pituitary gland with an imaging appearance that can overlap with that of pituitary adenoma. Differentiating the two before surgical resection can have important treatment implications. The purpose of our study was to determine whether it was possible to differentiate between granulomatous hypophysitis and pituitary adenoma on the basis of diffuse enhancing infrasellar basisphenoid bone marrow.
MATERIALS AND METHODS
We present 3 cases, initially thought to be pituitary adenomas, that were pathology-proved granulomatous hypophysitis. The preoperative MR images were reviewed for diffuse, enhancing infrasellar basisphenoid bone marrow. For comparison, we reviewed 100 cases of pathology-proved pituitary adenoma for the same finding. Additionally, imaging findings including the sphenoid sinus pneumatization pattern, clinical history, laboratory values, and pathology results were reviewed.
RESULTS
All 3 cases of granulomatous hypophysitis had diffuse enhancing infrasellar basisphenoid bone marrow. Conversely, this was not seen in any of the 100 pituitary adenomas. The patients with granulomatous hypophysitis were all women. Two patients had idiopathic granulomatous hypophysitis, and 1 had secondary granulomatous hypophysitis with sarcoidosis. Of the 100 patients with pituitary adenomas, 67 were women. The basisphenoid pneumatization patterns was as follows: 15 (type 2), 40 (type 3), and 45 (type 4).
CONCLUSIONS
We present 3 cases of granulomatous hypophysitis with diffuse enhancement of the infrasellar basisphenoid bone marrow that was not seen in our 100 cases of pituitary adenomas. This imaging feature may be valuable for suggesting a diagnosis of granulomatous hypophysitis and avoiding surgical resection of what might otherwise be misdiagnosed as a pituitary adenoma.
Topics: Humans; Female; Male; Pituitary Neoplasms; Diagnosis, Differential; Hypophysitis; Pituitary Gland; Autoimmune Hypophysitis; Magnetic Resonance Imaging
PubMed: 36007945
DOI: 10.3174/ajnr.A7618 -
Ulusal Travma Ve Acil Cerrahi Dergisi =... Apr 2022Pituitary apoplexy is an emergent and potential life-threatening complication of pituitary adenomas if not managed properly. The aim of our study is to present our...
BACKGROUND
Pituitary apoplexy is an emergent and potential life-threatening complication of pituitary adenomas if not managed properly. The aim of our study is to present our series of pituitary adenomas and to focus on the clinical, radiological, and surgical characteristics of this rare complication.
METHODS
In this study, a total of 143 patients with pituitary adenoma underwent surgical treatment between 2016 and 2018. All patients were operated using endoscopic endonasal transsphenoidal (EET) technique. The data of pituitary apoplexy cases were recorded. Resection rates, hormonal results, and visual outcomes of patients with pituitary apoplexy were evaluated.
RESULTS
Of the 143 patients, 8 (5.59%) were presented with the symptoms and radiological findings of pituitary apoplexy. The mean age was 26.75 years, and 4 (50%) of them were male and 4 were female. Pre-operative mean Knosp grading score was 2.1 All of eight patients underwent emergent surgical intervention and total resection was achieved in 75% of patients with apoplexy. Hormone levels were significantly decreased after surgery (p<0.05), except prolactin (p>0.05). Cerebrospinal fluid leakage occurred in one pa-tient. None of the patient with pituitary apoplexy died in our series.
CONCLUSION
Pituitary apoplexy is an important complication of pituitary adenomas. Early diagnosis and surgical intervention provide excellent ophthalmological and hormonal outcomes. Emergent EET approach is crucial for patients with ophthalmological findings and macroadenomas.
Topics: Adenoma; Adult; Endoscopy; Female; Humans; Male; Pituitary Apoplexy; Pituitary Neoplasms; Retrospective Studies
PubMed: 35485523
DOI: 10.14744/tjtes.2021.93539