ABSTRACT
A defining characteristic of mammalian prions is their capacity for self-sustained propagation. Theoretical considerations and experimental evidence suggest that prion propagation is modulated by cell-autonomous and non-autonomous modifiers. Using a novel quantitative phospholipase protection assay (QUIPPER) for high-throughput prion measurements, we performed an arrayed genome-wide RNA interference (RNAi) screen aimed at detecting cellular host-factors that can modify prion propagation. We exposed prion-infected cells in high-density microplates to 35,364 ternary pools of 52,746 siRNAs targeting 17,582 genes representing the majority of the mouse protein-coding transcriptome. We identified 1,191 modulators of prion propagation. While 1,151 modified the expression of both the pathological prion protein, PrPSc , and its cellular counterpart, PrPC , 40 genes selectively affected PrPSc . Of the latter 40 genes, 20 augmented prion production when suppressed. A prominent limiter of prion propagation was the heterogeneous nuclear ribonucleoprotein Hnrnpk. Psammaplysene A (PSA), which binds Hnrnpk, reduced prion levels in cultured cells and protected them from cytotoxicity. PSA also reduced prion levels in infected cerebellar organotypic slices and alleviated locomotor deficits in prion-infected Drosophila melanogaster expressing ovine PrPC . Hence, genome-wide QUIPPER-based perturbations can discover actionable cellular pathways involved in prion propagation. Further, the unexpected identification of a prion-controlling ribonucleoprotein suggests a role for RNA in the generation of infectious prions.
Subject(s)
Prion Diseases , Prions , Mice , Animals , Sheep/genetics , Prions/genetics , Prions/metabolism , Drosophila melanogaster/genetics , Ribonucleoproteins/metabolism , RNA Interference , RNA, Small Interfering/metabolism , Prion Diseases/genetics , Prion Diseases/pathology , Mammals/geneticsABSTRACT
Patients with prostate cancer frequently show resistance to androgen-deprivation therapy, a condition known as castration-resistant prostate cancer (CRPC). Acquiring a better understanding of the mechanisms that control the development of CRPC remains an unmet clinical need. The well-established dependency of cancer cells on the tumour microenvironment indicates that the microenvironment might control the emergence of CRPC. Here we identify IL-23 produced by myeloid-derived suppressor cells (MDSCs) as a driver of CRPC in mice and patients with CRPC. Mechanistically, IL-23 secreted by MDSCs can activate the androgen receptor pathway in prostate tumour cells, promoting cell survival and proliferation in androgen-deprived conditions. Intra-tumour MDSC infiltration and IL-23 concentration are increased in blood and tumour samples from patients with CRPC. Antibody-mediated inactivation of IL-23 restored sensitivity to androgen-deprivation therapy in mice. Taken together, these results reveal that MDSCs promote CRPC by acting in a non-cell autonomous manner. Treatments that block IL-23 can oppose MDSC-mediated resistance to castration in prostate cancer and synergize with standard therapies.
Subject(s)
Interleukin-23/antagonists & inhibitors , Interleukin-23/metabolism , Myeloid-Derived Suppressor Cells/metabolism , Prostatic Neoplasms, Castration-Resistant/pathology , Prostatic Neoplasms, Castration-Resistant/therapy , Androgen Receptor Antagonists/pharmacology , Androgen Receptor Antagonists/therapeutic use , Androgens/deficiency , Animals , Benzamides , Cell Proliferation , Cell Survival , Humans , Interleukin-23/blood , Interleukin-23/immunology , Male , Mice , Myeloid-Derived Suppressor Cells/cytology , Myeloid-Derived Suppressor Cells/immunology , Nitriles , Nuclear Receptor Subfamily 1, Group F, Member 3/metabolism , Phenylthiohydantoin/analogs & derivatives , Phenylthiohydantoin/pharmacology , Phenylthiohydantoin/therapeutic use , Prostatic Neoplasms, Castration-Resistant/blood , Prostatic Neoplasms, Castration-Resistant/metabolism , Receptors, Androgen/metabolism , Receptors, Interleukin/metabolism , Signal TransductionABSTRACT
TSH-secreting pituitary adenoma (TSHoma) is the rarest functioning pituitary tumor, with an increasing incidence over the last decades. Diagnosis is often delayed, exposing patients to a high risk of developing chronic complications of long-standing hyperthyroidism. Although thyroid hormone excess is a recognized cause of secondary osteoporosis, very few studies have investigated skeletal damage in patients with TSHoma, with data limited to bone turnover markers (BTM) and a study on the prevalence of radiological vertebral fractures (VFs) incidentally detected on chest X-ray, whereas data on bone mineral density (BMD) are anecdotal. Bone resorption is increased in TSHoma compared to controls, whereas few case reports described osteoporosis and spine fractures as early complications of TSHoma. A high prevalence of morphometric VFs was described in TSHoma compared to nonfunctioning pituitary adenoma (NFPA). Patients with fracture were older and had higher free thyroxine (fT4) levels than patients without fracture. In this specific setting, treatment with somatostatin receptor ligands seems to have a protective role on fracture risk. Based on this evidence, a comprehensive osteometabolic evaluation should be performed in all patients with TSHoma, including assessment of BTM, measurement of BMD, and morphometric evaluation of VFs, both at diagnosis and then during follow-up, particularly in patients at high risk for fragility fractures.
ABSTRACT
PURPOSE: Vertebral fractures (VFs), the hallmark of skeletal fragility, have been reported as an emerging complication in patients with pituitary diseases associated with hormonal excess and/or deficiency, independently from bone mineral density. Non-functioning pituitary adenoma (NFPA) is amongst the most frequent pituitary adenomas; however, skeletal health in this context has never been investigated. We aimed at assessing the prevalence and the determinants of morphometric VFs in patients with NFPA. METHODS: We enrolled 156 patients (79 M/77F, mean age 55.75 ± 12.94 years) at admission in Neurosurgery Unit before trans-sphenoidal surgery and compared them with an age and sex-matched control group of subjects with neither history/risk factors for secondary osteoporosis nor pituitary disorders. We performed a vertebral morphometric evaluation of the thoracic spine on pre-operative X-ray images (MTRx) and collected biochemical, demographic, and clinical data from the entire cohort. RESULTS: The prevalence of thoracic VFs in patients with NFPA was significantly higher than the control group (26.3% vs. 10.3%; p < 0.001). In the NFPA group, 20 patients (48.8% of the fractured patients) showed multiple VFs, 14 (34.1% of them) showed moderate/severe VFs. Patients with VFs were significantly older and had lower serum free triiodothyronine (fT3) levels than non-fractured ones (p = 0.002 and p = 0.004; respectively). The prevalence of secondary male hypogonadism was higher among men with VFs as compared to those with no VFs (72% vs. 48.1%; p = 0.047). Consistently, total testosterone levels in males were significantly lower in fractured patients than in non-fractured ones (p = 0.02). The prevalence of gonadotroph adenomas was significantly higher among patients with VFs (p = 0.02). In multiple logistic regression analysis, older age and lower serum fT3 levels were independent factors predicting the risk for VFs. CONCLUSIONS: For the first time, we reported a high prevalence of thoracic radiological VFs in patients with NFPAs. Our data should prompt clinicians to proceed with a clinical bone fragility evaluation already during the diagnostic work-up, particularly in those with concomitant hypogonadism, or in those with older age and/or with lower fT3.
Subject(s)
Pituitary Neoplasms , Spinal Fractures , Humans , Middle Aged , Male , Female , Pituitary Neoplasms/diagnostic imaging , Pituitary Neoplasms/epidemiology , Pituitary Neoplasms/pathology , Pituitary Neoplasms/complications , Spinal Fractures/epidemiology , Spinal Fractures/diagnostic imaging , Aged , Prevalence , Adult , Adenoma/diagnostic imaging , Adenoma/epidemiology , Adenoma/pathology , Bone Density , Thoracic Vertebrae/diagnostic imaging , Thoracic Vertebrae/pathology , Risk FactorsABSTRACT
INTRODUCTION: The glucocorticoid receptor is pivotal to control corticotrophin (ACTH) secretion, and its function is closely linked to the heat shock protein 90 (HSP90) chaperone complex. Impaired sensitivity to glucocorticoid feedback is a hallmark of human corticotroph adenomas, i.e., Cushing's disease, a disorder with few medical treatment options. Silibinin, a HSP90 inhibitor, has been studied in tumoral corticotroph cells and its use proposed in Cushing's disease. Aim of the present study was to further investigate the effect of silibinin on human corticotroph adenomas in vitro. METHODS: Seven human ACTH-secreting pituitary adenomas were established in culture and treated with 10-50 µ
Subject(s)
ACTH-Secreting Pituitary Adenoma , Adenoma , Antineoplastic Agents , Pituitary ACTH Hypersecretion , Humans , ACTH-Secreting Pituitary Adenoma/genetics , Receptors, Glucocorticoid/genetics , Silybin/pharmacology , Pituitary ACTH Hypersecretion/drug therapy , Pro-Opiomelanocortin/metabolism , Adenoma/metabolism , Adrenocorticotropic Hormone/metabolism , Dexamethasone/pharmacologyABSTRACT
Pituitary gland tumors represent approximately 10-15% of all brain tumors and the most common neoplasms of the sellar region. Among them, pituitary adenomas are the widespread accounting for more than 80%. Recently, the fourth edition of the World Health Organization (WHO) 2017 classified pituitary tumors focusing on histopathologic and molecular genetics features and introduced new entities like pituitary blastoma. Most of pituitary gland neoplasms occur sporadically, whereas 5% are related to familial syndromes. They present with several clinical manifestations including signs and symptoms related to excessive hormone secretion by the tumor, signs of hormone deficits by the normal pituitary gland and others commonly secondary to mass effects, and compression of nearby structures such as the optic chiasm; headache and visual disturbance are the most frequent mass effect symptoms. Some tumors, however, are detected as an incidental finding on magnetic resonance imaging (MRI) or computed tomography (CT) scans performed for some other reasons. A correct evaluation involves the assessment of hypothalamic-pituitary hormonal function and an ophthalmological examination once a pituitary lesion is encountered. Surgery, more specifically transsphenoidal approach, represents the primary treatment chosen for the majority of pituitary tumors (except for prolactinomas where medical treatment is indicated) allowing for pathologic analysis and complete or partial tumor removal. On the contrary, to date, craniotomy is rarely performed. Sometimes, due to the proximity of critical structures and to tumor's location and characteristics, a successful surgical procedure may often not be achievable due to the high risks related to the procedure itself. Therefore, the treatment of pituitary tumors commonly requires a multimodal approach, including surgery, radiosurgery, radiation therapy, and medical therapy. Aggressive pituitary tumors or carcinomas are associated with poor prognosis due to limited therapeutic options. Furthermore, they tend to recur quickly after initial surgical treatment or present metastasis, may be unresponsive to therapy, and are difficult to manage. In this chapter, we provide an overview of the most common pituitary gland tumors focusing on epidemiology, new pathological features, diagnosis, available treatment, and prognosis.
Subject(s)
Adenoma , Pituitary Neoplasms , Humans , Pituitary Neoplasms/diagnostic imaging , Pituitary Neoplasms/genetics , Neoplasm Recurrence, Local , Pituitary Gland/pathology , Adenoma/diagnosis , Adenoma/pathology , Adenoma/surgery , Hormones , Magnetic Resonance ImagingABSTRACT
Craniopharyngiomas are rare malignancies of dysembryogenic origin, involving the sellar and parasellar areas. These low-grade, epithelial tumors account for two main histological patterns (adamantinomatous craniopharyngioma and papillary craniopharyngioma), which differ in epidemiology, pathogenesis, and histomorphological appearance. Adamantinomatous craniopharyngiomas typically show a bimodal age distribution (5-15 years and 45-60 years), while papillary craniopharyngiomas are limited to adult patients, especially in the fifth and sixth decades of life. Recently, craniopharyngioma histological subtypes have been demonstrated to harbor distinct biomolecular signatures. Somatic mutations in CTNNB1 gene encoding ß-catenin have been exclusively detected in adamantinomatous craniopharyngiomas, which predominantly manifest as cystic lesions, while papillary craniopharyngiomas are driven by BRAF V600E mutations in up to 95% of cases and are typically solid masses. Despite the benign histological nature (grade I according to the World Health Organization classification), craniopharyngiomas may heavily affect long-term survival and quality of life, due to their growth pattern in a critical region for the presence of eloquent neurovascular structures and possible neurological sequelae following their treatment. Clinical manifestations are mostly related to the involvement of hypothalamic-pituitary axis, optic pathways, ventricular system, and major blood vessels of the circle of Willis. Symptoms and signs referable to intracranial hypertension, visual disturbance, and endocrine deficiencies should promptly raise the clinical suspicion for sellar and suprasellar pathologies, advocating further neuroimaging investigations, especially brain MRI. The optimal therapeutic management of craniopharyngiomas is still a matter of debate. Over the last decades, the surgical strategy for craniopharyngiomas, especially in younger patients, has shifted from the aggressive attempt of radical resection to a more conservative and individualized approach via a planned subtotal resection followed by adjuvant radiotherapy, aimed at preserving functional outcomes and minimizing surgery-related morbidity. Whenever gross total removal is not safely feasible, adjuvant radiotherapy (RT) and stereotactic radiosurgery (SRS) have gained an increasingly important role to manage tumor residual or recurrence. The role of intracavitary therapies, including antineoplastic drugs or sealed radioactive sources, is predominantly limited to monocystic craniopharyngiomas as secondary therapeutic option. Novel findings in genetic profiling of craniopharyngiomas have unfold new scenarios in the development of targeted therapies based on brand-new biomolecular markers, advancing the hypothesis of introducing neoadjuvant chemotherapy regimens in order to reduce tumor burden prior to resection. Indeed, the rarity of these neoplasms requires a multispecialty approach involving an expert team of endocrinologists, neurosurgeons, neuro-ophthalmologists, neuroradiologists, radiotherapists, and neuro-oncologists, in order to pursue a significant impact on postoperative outcomes and long-term prognosis.
Subject(s)
Craniopharyngioma , Pediatrics , Pituitary Neoplasms , Radiosurgery , Child , Humans , Adult , Child, Preschool , Adolescent , Craniopharyngioma/genetics , Craniopharyngioma/therapy , Craniopharyngioma/diagnosis , Quality of Life , Pituitary Neoplasms/genetics , Pituitary Neoplasms/therapy , Pituitary Neoplasms/diagnosisABSTRACT
Sellar melanocytomas represent a small subgroup of primary melanocytic tumors arising from leptomeningeal melanocytes. They are benign, slow-growing tumors with a high risk of recurrence. We report two cases of sellar melanocytoma treated at the same institute. A 35-year-old woman presented with amenorrhea and an intrasellar mass with suprasellar extension simulating a hemorrhagic pituitary adenoma. The second case is a 51-year-old man with progressive visual loss and a recurrence of primary sellar and suprasellar melanocytoma. The first patient underwent gross total resection and the second patient underwent subtotal resection. Neither of them was treated with postoperative adjuvant therapies. The second patient had tumor regrowth 75 months after surgery; he therefore underwent gamma knife radiosurgery. Both patients are alive and well at the last follow-up (140 and 93 months, respectively).
Subject(s)
Adenoma , Pituitary Neoplasms , Adult , Female , Humans , Male , Middle Aged , Adenoma/surgery , Combined Modality Therapy , Magnetic Resonance Imaging , Pituitary Neoplasms/diagnostic imaging , Pituitary Neoplasms/surgery , SkullABSTRACT
PURPOSE: Patients suffering from craniopharyngiomas currently have good survival rates, but long-term sequelae, such as development of obesity, worsen their quality of life. Optimal treatment is still controversial and changed during the decades, becoming less aggressive. Transcranial (TC) surgery was the first approach to be used, followed by extended transsphenoidal (eTNS) access. This study aims to compare the two approaches in terms of risk of hypothalamic damage leading to obesity. METHODS: This is a monocentric retrospective analysis of post-puberal patients treated for primary craniopharyngioma. Postoperative obesity and percentual postsurgical BMI variation were considered proxy for hypothalamic function and used to fit regression models with basal BMI, type of surgery, tumor volume and hypothalamic involvement (anterior vs. anteroposterior). RESULTS: No difference in radicality was observed between the two approaches; eTNS was more effective in ameliorating visual function but was significantly associated with CSF leaks. The TC approach was associated with a higher incidence of diabetes insipidus. Regression analysis showed only tumor volume and basal BMI resulted as independent predictors for both postoperative obesity (respectively, OR 1.15, P = 0.041, and OR 1.57, P < 0.001) and percentual BMI variation (respectively, + 0.92%, P = 0.005, and - 1.49%, P = 0.001). CONCLUSIONS: Larger lesions portend a higher risk to develop postoperative obesity, independently of hypothalamic involvement. Interestingly, basal BMI is independent of lesional volume and is associated with postoperative obesity, but lesser postoperative BMI variation. The surgical approach does not influence the obesity risk. However, eTNS proves valid in managing large tumors with important hypothalamic invasion.
Subject(s)
Craniopharyngioma , Pituitary Neoplasms , Craniopharyngioma/surgery , Humans , Obesity , Pituitary Neoplasms/surgery , Postoperative Complications , Quality of Life , Retrospective Studies , Treatment OutcomeABSTRACT
OBJECTIVE: Gamma knife radiosurgery (GKRS) has proven to be an effective adjuvant treatment for patients with acromegaly. We performed the present study to investigate, which would be the outcome of GKRS, independently on the response to somatostatin receptor ligand (SRL). DESIGN: Retrospective, observational study. PATIENTS: Ninety-six patients with active acromegaly were included. MEASUREMENTS: The cumulative probability of normalisation of insulin-like growth factor 1 (IGF-1) levels after GKRS was assessed by the Kaplan-Meier method. The association of several clinical characteristics with GKRS outcomes was explored with the use of a Cox proportional-hazard model with the relative hazard ratio and 95% confidence interval (CI). RESULTS: Resistance to SRL occurred in 39 of the 96 patients (40.6%). After GKRS, patients resistant to SRL had a 5- and 10-year probability of remission of 40.7% (95% CI: 23.7%-57.7%) and 75.9% (95% CI: 57.9%-93.9%), respectively. Patients responding to SRL had a 5- and 10-year probability of remission of 46.8% (95% CI: 32.2%-61.4%) and 58.1% (95% CI: 41.5%-74.7%), respectively. The difference was not significant (p = .48 by the log-rank test). Multivariate Cox analysis confirmed that the only independent variables associated with GKRS outcome were basal growth hormone (GH; p = .001) and IGF-1 multiple of the upper limit of normal levels before GKRS (p = .013). CONCLUSION: We demonstrate for the first time that the responsiveness to SRL has no effect on the probability to obtain remission of acromegaly after GKRS. The remission of disease occurred more frequently in patients who had lower GH and IGF-1 levels before GKRS.
Subject(s)
Acromegaly , Radiosurgery , Acromegaly/drug therapy , Acromegaly/surgery , Humans , Ligands , Receptors, Somatostatin , Retrospective Studies , Treatment OutcomeABSTRACT
BACKGROUND: Widespread use of silver in its different forms raises concerns about potential adverse effects after ingestion, the main exposure route for humans. The aim of this study was to investigate in CD-1 (ICR) male mice the tissue distribution and in vivo effects of 4-week oral exposure to 0.25 and 1 mg Ag/kg bw 10 nm citrate coated silver nanoparticles (AgNPs) and 1 mg Ag/kg bw silver acetate (AgAc) at the end of treatment (EoT) and after 4 weeks of recovery. RESULTS: There were no treatment-related clinical signs and mortality, and no significant effects on body and organ weights at the EoT and after recovery. Treatment-related changes in hematology and clinical chemistry were found after recovery, the most relevant being a dose-dependent lymphopenia and increased triglycerides in AgNP-treated mice, and increased levels of urea in all treated groups, associated with decreased albumin only in AgAc-treated mice. At the EoT the highest silver concentration determined by Triple Quadrupole ICP-MS analysis was found in the brain, followed by testis, liver, and spleen; much lower concentrations were present in the small intestine and kidney. Tissue silver concentrations were slightly higher after exposure to AgAc than AgNPs and dose dependent for AgNPs. After recovery silver was still present in the brain and testis, highlighting slow elimination. No histopathological changes and absence of silver staining by autometallography were observed in the organs of treated mice. At the EoT GFAP (astrocytes) immunoreactivity was significantly increased in the hippocampus of AgNP-treated mice in a dose-dependent manner and Iba1 (microglial cells) immunoreactivity was significantly increased in the cortex of 1 mg/kg bw AgNP-treated mice. After recovery, a significant reduction of Iba1 was observed in the cortex of all treated groups. TEM analysis of the hippocampus revealed splitting of basement membrane of the capillaries and swelling of astrocytic perivascular end-feet in 1 mg/kg bw AgNP- and AgAc-treated mice at the EoT. CONCLUSIONS: Our study revealed accumulation and slow clearance of silver in the brain after oral administration of 10 nm AgNPs and AgAc at low doses in mice, associated with effects on glial cells and ultrastructural alterations of the Blood-Brain Barrier.
Subject(s)
Metal Nanoparticles/toxicity , Silver/toxicity , Administration, Oral , Animals , Brain , Male , Mice , Mice, Inbred ICR , Tissue DistributionABSTRACT
PURPOSE: To analyse the efficacy and safety of the transsphenoidal microsurgical approach with open sella technique (OST) for the treatment of pituitary adenoma (PA) with suprasellar extension. METHODS: We retrospectively reviewed 2305 consecutive patients with PA who underwent their first surgery through the transsphenoidal microsurgical approach at our department between 1990 and 2018. Focusing on tumours with suprasellar extension, in particular, grade B, C and D adenomas according to Wilson-Hardy's classification, 376 patients who received the OST surgery were identified. Outcomes and complications were evaluated and compared with those obtained in patients who underwent a standard transsphenoidal approach (TSM). RESULTS: Two-hundred and sixty-four of 376 patients (70.2%) were found to be suffering from a non-functioning pituitary adenoma, whereas 112 of 376 patients (29.8%) from a hormone-secreting PA. The mean craniocaudal diameter of the tumor was 30.6 ± 0.3 mm (range, 21-75 mm) and 151 patients (40.1%) had a cavernous sinus invasion too. An overall surgical remission rate of 50.3% was achieved in the OST group, whereas the recurrence rate was 10.5%. Patients were followed for a mean period of 68 ± 1.4 months (range, 6-96 months). Less postoperative intrasellar haemorrhages have been recorded in the OST group than the TSM one (1.1% vs. 4.6%, p = 0.02). CONCLUSIONS: In experienced hands, OST represents an effective and safe treatment strategy for PA with suprasellar extension.
ABSTRACT
Surgical experience is of paramount importance to reach therapeutic success and minimize operative complications. In the field of pituitary surgery, this led to the concept of Pituitary Center of Excellence (PTCOE) defined as a center where an interdisciplinary team works in collaboration and where surgeons can be trained appropriately to reach and keep excellence in daily practice. To review the literature to define the optimal referral population size to establish a PTCOE to optimize both training and specific field research. A review of the literature was performed about epidemiology. The time needed to observe 200 cases of PAs in a single PTCOE and to reach the minimal surgical experience threshold (MSET) was calculated for different referral population groups. The time needed to reach MSET decreased as population size increased. We defined a population as the optimal one to be served by a single PTCOE with a single dedicated neurosurgeon. PTCOEs should be established after an analysis of the referral population, number of cases suitable for surgical treatment and number of dedicated neurosurgeons.
Subject(s)
Clinical Competence/statistics & numerical data , Neurosurgeons/statistics & numerical data , Neurosurgical Procedures/statistics & numerical data , Pituitary Neoplasms/surgery , Referral and Consultation/statistics & numerical data , Tertiary Care Centers/statistics & numerical data , HumansABSTRACT
The 13th Acromegaly Consensus Conference was held in November 2019 in Fort Lauderdale, Florida, and comprised acromegaly experts including endocrinologists and neurosurgeons who considered optimal approaches for multidisciplinary acromegaly management. Focused discussions reviewed techniques, results, and side effects of surgery, radiotherapy, and medical therapy, and how advances in technology and novel techniques have changed the way these modalities are used alone or in combination. Effects of treatment on patient outcomes were considered, along with strategies for optimizing and personalizing therapeutic approaches. Expert consensus recommendations emphasize how best to implement available treatment options as part of a multidisciplinary approach at Pituitary Tumor Centers of Excellence.
Subject(s)
Acromegaly/therapy , Consensus , Dopamine Agonists/therapeutic use , Neurosurgical Procedures , Patient Care Team , Practice Guidelines as Topic , Radiotherapy , Receptors, Somatotropin/antagonists & inhibitors , Somatostatin/analysis , Acromegaly/diagnosis , Humans , Neurosurgical Procedures/methods , Neurosurgical Procedures/standards , Radiotherapy/methods , Radiotherapy/standardsABSTRACT
Parasellar tumours represent a wide group of intracranial lesions, both benign and malignant. They may arise from several structures located within the parasellar area or they may infiltrate or metastasize this region. The treatment of the tumours located in these areas is challenging because of their complex anatomical location and their heterogenous histology. It often requires a multimodal approach, including surgery, radiation therapy (RT), and medical therapy. Due to the proximity of critical structures and the risks of side effects related to the procedure, a successful surgical resection is often not achievable. Thus, RT plays a crucial role in the treatment of several parasellar tumours. Conventional fractionated RT and modern radiation techniques, like stereotactic radiosurgery and proton beam RT, have become a standard management option, in particular for cases with residual or recurrent tumours after surgery and for those cases where surgery is contraindicated. This review examines the role of RT in parasellar tumours analysing several techniques, outcomes and side effects.
Subject(s)
Brain Neoplasms/radiotherapy , Chondrosarcoma/radiotherapy , Chordoma/radiotherapy , Cranial Irradiation/standards , Craniopharyngioma/radiotherapy , Meningeal Neoplasms/radiotherapy , Meningioma/radiotherapy , Pituitary Neoplasms/radiotherapy , Radiosurgery/standards , Cranial Irradiation/adverse effects , Humans , Radiosurgery/adverse effectsABSTRACT
BACKGROUND: Somatic mutations in the ubiquitin-specific protease 8 (USP8) gene have recently been shown to occur in ACTH-secreting pituitary adenomas, thus calling attention to the ubiquitin system in corticotrope adenomas. OBJECTIVES: Assess the consequences of USP8 mutations and establish the role of ubiquitin on ACTH turnover in human ACTH-secreting pituitary adenomas. METHODS: USP8 mutation status was established in 126 ACTH-secreting adenomas. Differences in ACTH secretion and POMC expression from adenoma primary cultures and in microarray gene expression profiles from archival specimens were sought according to USP8 sequence. Ubiquitin/ACTH coimmunoprecipitation and incubation with MG132, a proteasome inhibitor, were performed in order to establish whether ubiquitin plays a role in POMC/ACTH degradation in corticotrope adenomas. RESULTS: USP8 mutations were identified in 29 adenomas (23%). Adenomas presenting USP8 mutations secreted greater amounts of ACTH and expressed POMC at higher levels compared to USP wild-type specimens. USP8 mutant adenomas were also more sensitive to modulation by CRH and dexamethasone in vitro. At microarray analysis, genes associated with endosomal protein degradation and membrane components were downregulated in USP8 mutant adenomas as were AVPR1B, IL11RA, and PITX2. Inhibition of the ubiquitin-proteasome pathway increased ACTH secretion and POMC itself proved a target of ubiquitylation, independently of USP8 sequence status. CONCLUSIONS: Our study has shown that USP8 mutant ACTH-secreting adenomas present a more "typical" corticotrope phenotype and reduced expression of several genes associated with protein degradation. Further, ubiquitylation is directly involved in intracellular ACTH turnover, suggesting that the ubiquitin-proteasome system may represent a target for treatment of human ACTH-secreting adenomas.
Subject(s)
ACTH-Secreting Pituitary Adenoma/genetics , ACTH-Secreting Pituitary Adenoma/metabolism , Adenoma/genetics , Adenoma/metabolism , Endopeptidases/genetics , Endosomal Sorting Complexes Required for Transport/genetics , Pituitary ACTH Hypersecretion/metabolism , Pro-Opiomelanocortin/metabolism , Ubiquitin Thiolesterase/genetics , Ubiquitination , Adolescent , Adult , Aged , Female , Gene Expression Profiling , Humans , Male , Middle Aged , Tumor Cells, Cultured , Young AdultABSTRACT
PURPOSE: Aggressive pituitary adenomas (APAs) and pituitary carcinomas (PCs) are challenging for their invasive nature, resistance to treatment and recurrences. Temozolomide (TMZ) is used with benefit and well-tolerated toxicity profile in APAs and PCs. In most studies patients received ≤ 12 cycles but the best length of treatment is debated since other options after discontinuation are scarce and a second course is mainly unsuccessful. METHODS: We report outcomes of 8 patients with APAs and PCs treated with TMZ for more than 12 continuous cycles with a literature review. Data were retrospectively collected from Padua and Milan University Hospitals. TMZ was used as a single agent (150-200 p.o. mg/m2 daily, 5/28 days) for 14 to 45 cycles. RESULTS: Eight patients (7 M), 7 APAs and 1 PC. Previous treatments included neurosurgery and radiotherapy in all cases except two giant masses (ACTH-silent APA and prolactinoma). No patient had progression disease (PD) during long-term treatment nor toxicities. No one had complete response (CR) but four had partial response (PR). Four ACTH+ tumors maintained stable disease (SD) but the secretion pattern improved in all. After drug withdrawal, three had delayed PD (2 after 18 and one after 29 months, all ACTH+); two are still in SD. CONCLUSIONS: TMZ may be useful and well-tolerated in APAs and PCs as a long-term therapy. PR appears within the first cycles with no escape throughout the treatment; most patients achieve SD. We suggest extended protocols particularly in responsive ACTH+ PAs and PCs, when further therapies may be unsuccessful.
Subject(s)
Adenoma/drug therapy , Antineoplastic Agents, Alkylating/therapeutic use , Carcinoma/drug therapy , Duration of Therapy , Neoplasm Recurrence, Local/drug therapy , Pituitary Neoplasms/drug therapy , Temozolomide/therapeutic use , ACTH-Secreting Pituitary Adenoma/drug therapy , ACTH-Secreting Pituitary Adenoma/pathology , Adenoma/pathology , Adult , Aged , Carcinoma/pathology , Chemotherapy, Adjuvant , Female , Humans , Italy , Male , Middle Aged , Neoplasm Recurrence, Local/pathology , Neurosurgical Procedures , Pituitary Neoplasms/pathology , Progression-Free Survival , Prolactinoma/drug therapy , Prolactinoma/pathology , Radiosurgery , Radiotherapy, AdjuvantABSTRACT
PURPOSE: Acromegaly may be associated with an increased risk of complex intraoperative management and anesthetic complications. No study addressed whether pretreatment with somatostatin receptor ligands (SRLs) affects anesthesiologic management. METHODS: We studied 211 consecutive acromegalic patients who had a recorded intraoperative computerized anesthetic record (ICAR) available for analysis. Ninety-six (45.5%) patients were SRL-pretreated while 115 patients were treatment naïve. RESULTS: Treatment with SRLs reduced mean basal growth hormone level from 23.8 ± 4.2 to 5.9 ± 1.3 µg/L. Normalization of insulin-like growth factor-1 was achieved in 26 patients (27.1%). The frequency of comorbidities at surgery was similar in the two groups. Five patients with difficult intubation were naïve (4.3%) as compared with 5 SRL-pretreated patients (5.2%; P = 1.0). ICAR registration did not show any significant change of intraoperative vital parameters in the two groups of patients as well as in the intraoperative utilization of drugs. Total duration of anesthesia and surgery were similar in the two groups. Four patients with an intraoperative adverse event were naïve (3.5%) as compared with 4 SRL-pretreated patients (4.2%; P = 1.00). Remission of disease occurred in 83 of 114 naïve patients (72.8%) and in 57 of 93 SRL-pretreated patients (61.3%; P = 0.11). CONCLUSIONS: SRL-pretreatment of patients with acromegaly had no significant impact on intraoperative anesthesiologic management. Despite a better Cormack-Lehane score in SRL-pretreated than in naïve patients, the rate of difficult intubation was similar in both groups. SRL-pretreatment did not affect the rate of surgical remission or complications as well.
Subject(s)
Anesthesia/methods , Pituitary Neoplasms/drug therapy , Somatostatin/analogs & derivatives , Somatostatin/therapeutic use , Acromegaly , Female , Humans , Male , Middle Aged , Monitoring, Intraoperative , Pituitary Neoplasms/metabolism , Receptors, Somatostatin/metabolism , Retrospective StudiesABSTRACT
Encephalocele is a rare malformation consisting in herniation of cranial contents through a cranial defect. A transsphenoidal location is uncommon, representing 5% of all basal encephaloceles. The surgical treatment of transsphenoidal encephaloceles is challenging. An optimal approach has not yet been determined, and it varies according to the surgical experience. We report the surgical management of a transsphenoidal encephalocele. The encephalocele and the sellar defect were repaired through a sublabial transsphenoidal microsurgical approach (TSM). Preoperative magnetic resonance imaging (MRI) and computed tomography (CT) scans were crucial for surgical planning. The sublabial transsphenoidal microsurgical approach offered a good and complete exposure of both the sac and the bone defect. Therefore, the congenital defect was successfully repaired with complete resolution of the encephalocele without any surgical or medical complications. Postoperative CT scan and MRI showed the restoration of the bone defect and the recovery of a normal anatomy with herniated structures pushed back into the sella. The described sublabial transsphenoidal microsurgical approach represents a minimally invasive, safe, and effective treatment strategy for transsphenoidal encephalocele.
Subject(s)
Encephalocele/congenital , Encephalocele/surgery , Microsurgery/methods , Child, Preschool , Humans , Labial Frenum , Magnetic Resonance Imaging , Male , Sphenoid Bone/surgery , Tomography, X-Ray Computed , Treatment OutcomeABSTRACT
PURPOSE: Chiasmapexy is a poorly described surgical procedure adopted to correct the downward displacement of suprasellar visual system (SVS) into an empty sella (ES) causing visual worsening. The aim of our study is to define the indications for extradural and intradural chiasmapexy. METHODS: A systematic literature review has been performed on MEDLINE database (US National Library of Medicine), including only articles that depicted cases of surgically treated patients affected by ES and progressive delayed visual worsening. Moreover, we have reported three cases of secondary ES syndrome (SESS) with visual worsening treated in our Department with transsphenoidal (TS) microsurgical intradural approach. Finally, we have compared the results of extradural and intradural chiasmapexy described in literature. RESULTS: The etiology of visual impairment is different in primary and secondary ESS. In primary ESS (PESS) the only predisposing factor is a dehiscence of diaphragma sellae, and the anatomical distortion caused by displacement of optic chiasm or traction of pituitary stalk and infundibulum may determine a direct injury of neural fibers and ischemic damage of SVS. In PESS the mechanical elevation of SVS performed through extradural approach is sufficient to resolve the main pathologic mechanism. In SESS, arachnoidal adhesions play an important role in addition to downward herniation of SVS. Consequently, the surgical technique should provide elevation of SVS combined to intradural release of scar tissue and arachnoidal adhesions. In treatment of SESS, the intradural approaches result to be more effective, guaranteeing the best visual outcomes with the lowest complications rates. CONCLUSIONS: The intradural chiasmapexy is indicated in treatment of SESS, instead the extradural approaches are suggested for surgical management of PESS.