Common mutations of beta-catenin in adamantinomatous craniopharyngiomas but not in other tumours originating from the sellar region

Multi-omics analysis of adamantinomatous craniopharyngiomas reveals distinct molecular subgroups with prognostic and treatment response significance

BACKGROUND

Adamantinomatous craniopharyngioma (ACP) is the commonest pediatric sellar tumor. No effective drug is available and interpatient heterogeneity is prominent. This study aimed to identify distinct molecular subgroups of ACP based on the multi-omics profiles, imaging findings, and histological features, in order to predict the response to anti-inflammatory treatment and immunotherapies.

METHODS

Totally 142 Chinese cases diagnosed with craniopharyngiomas were profiled, including 119 ACPs and 23 papillary craniopharyngiomas. Whole-exome sequencing (151 tumors, including recurrent ones), RNA sequencing (84 tumors), and DNA methylome profiling (95 tumors) were performed. Consensus clustering and non-negative matrix factorization were used for subgrouping, and Cox regression were utilized for prognostic evaluation, respectively.

RESULTS

Three distinct molecular subgroups were identified: WNT, ImA, and ImB. The WNT subgroup showed higher Wnt/β-catenin pathway activity, with a greater number of epithelial cells and more predominantly solid tumors. The ImA and ImB subgroups had activated inflammatory and interferon response pathways, with enhanced immune cell infiltration and more predominantly cystic tumors. Mitogen-activated protein kinases (MEK/MAPK) signaling was activated only in ImA samples, while IL-6 and epithelial-mesenchymal transition biomarkers were highly expressed in the ImB group, mostly consisting of children. The degree of astrogliosis was significantly elevated in the ImA group, with severe finger-like protrusions at the invasive front of the tumor. The molecular subgrouping was an independent prognostic factor, with the WNT group having longer event-free survival than ImB (Cox, P = 0.04). ImA/ImB cases were more likely to respond to immune checkpoint blockade (ICB) therapy than the WNT group ( P <0.01). In the preliminary screening of subtyping markers, CD38 was significantly downregulated in WNT compared with ImA and ImB ( P = 0.01).

CONCLUSIONS

ACP comprises three molecular subtypes with distinct imaging and histological features. The prognosis of the WNT type is better than that of the ImB group, which is more likely to benefit from the ICB treatment.

Rathke's Cleft Cyst and Craniopharyngioma: A Continuum of the Same Spectrum? Insights from an Interesting Case and Previous Literature

Rathke's Cleft Cysts (RCCs) and Craniopharyngiomas (CPs) may represent disease entities on the same etio-pathological spectrum. We report the case of a 36-year-old female presenting with vision loss and menstrual irregularities, imaging shows a predominantly cystic lesion in the sellar region with suprasellar extension. She underwent a microscopic transnasal resection of the lesion. She later presented with recurrent symptoms and increased residual lesion size on imaging, a transcranial excision of the lesion was performed. Histopathology from the initial operative specimen revealed RCC with squamous metaplasia which was BRAF negative, while the specimen from the second surgery revealed BRAF positive papillary stratified squamous architecture suggestive of Papillary CP. This case adds to the evidence that both RCCs and papillary CPs may be the spectrum of the same disease. Further, papillary CPs may be an evolution from the RCCs.

Integrating Systemic Therapies into the Multimodality Therapy of Patients with Craniopharyngioma

OPINION STATEMENT

The integration of targeted therapy into the multimodal management of craniopharyngiomas represents a significant advancement in the field of neuro-oncology. Historically, the management of these tumors has been challenging due to their proximity to vital brain structures, necessitating a delicate balance between tumor control and the preservation of neurological function. Traditional treatment modalities, such as surgical resection and radiation, while effective, carry their own set of risks, including potential damage to surrounding healthy tissues and the potential for long-term side effects. Recent insights into the molecular biology of craniopharyngiomas, particularly the discovery of the BRAF V600E mutation in nearly all papillary craniopharyngiomas, have paved the way for a targeted systemic treatment approach. However, advances have been limited for adamantinomatous craniopharyngiomas. The success of BRAF/MEK inhibitors in clinical trials underscores the potential of these targeted therapies not only to control tumor growth but also to reduce the need for more invasive treatments, potentially minimizing treatment-related complications. However, the introduction of these novel therapies also brings forth new challenges, such as determining the optimal timing, sequencing, and duration of targeted treatments. Furthermore, there are open questions regarding which specific BRAF/MEK inhibitors to use, the potential need for combination therapy, and the strategies for managing intolerable adverse events. Finally, ensuring equitable access to these therapies, especially in healthcare systems with limited resources, is crucial to prevent widening healthcare disparities. In conclusion, targeted therapy with BRAF/MEK inhibitors holds great promise for improving outcomes and quality of life for patients with BRAF-mutated craniopharyngiomas. However, additional research is needed to address the questions that remain about its optimal use and integration into comprehensive treatment plans.

Pediatric craniopharyngiomas: magnetic resonance imaging assessment for hypothalamus-pituitary axis dysfunction and outcome prediction

BACKGROUND

In adamantinomatous craniopharyngiomas, tumor topographical categories, cystic component volume, and magnetic resonance signal intensity may impact prognosis.

OBJECTIVE

To identify magnetic resonance imaging (MRI) variables associated with pituitary-hypothalamic axis dysfunction and predictive of outcome in children with cystic adamantinomatous craniopharyngiomas.

MATERIALS AND METHODS

We evaluated 40 preoperative MRIs of adamantinomatous craniopharyngiomas to classify tumor topography, volume, and signal intensity of the cystic components and peritumoral edema. Volumes and normalized signal intensity minimum values were extracted from coronal T2-weighted images (nT2min). Radiological variables were compared to pituitary-hypothalamic axis dysfunction-related clinical data and surgical outcomes.

RESULTS

Adamantinomatous craniopharyngiomas were categorized into five topographic classes (12 patients, sellar-suprasellar; seven patients, pseudo-intraventricular; six patients, strict intraventricular; 14 patients, secondary intraventricular; one patient, not strict intraventricular). All cases exhibited a predominant (30 patients, 80%) or total (10 patients, 20%) cystic tumor component and displayed low nT2min percentage values compared to cerebrospinal fluid (42.3% [interquartile range 28.4-54.6%]). Significant associations between tumor topographic classes and pituitary dysfunction (P<0.001), and between peritumoral edema and hypothalamic dysfunction (P<0.001) were found. Considering extent of surgical removal and tumor relapse, volume of the cystic tumor component displayed a positive correlation (P=0.002; r=0.48; P=0.02; r=0.36), while nT2min intensity values exhibited a negative correlation (P=0.01; r= - 0.40; P=0.028; r= - 0.34).

CONCLUSION

Severe hypothalamic-pituitary axis dysfunction is associated with tumors along the pituitary stalk and peritumoral edema. Tumor invasion of the third ventricle, tight adherence to the hypothalamus, larger volumes, and lower nT2min intensity of the tumor cystic component are independent predictors of extent of adamantinomatous craniopharyngioma excision and recurrence.

First evidence of anti-VEGF efficacy in an adult case of adamantinomatous craniopharyngioma: Case report and illustrative review

BACKGROUND

Craniopharyngioma (CP) is a neurosurgical challenge, due to location and to the substantial risk of morbidity associated with surgical resection. Recent advances in molecular research have identified a mutation signature in papillary craniopharyngiomas: BRAF V600E. This has led to targeted therapy, yielding positive results. Despite numerous studies of the pathophysiology of adamantinomatous craniopharyngioma, treatment options for molecular-based therapy are still lacking. The objective of our study was to provide an illustrative review of the literature on possible molecular targets in adamantinomatous craniopharyngioma and to report the case of a patient harboring an adamantinomatous craniopharyngioma deemed unsuitable for surgical resection, in which an anti-VEGF antibody was used to achieve tumor control.

CASE REPORT

An 84-year-old-man was referred to our department with a history of visual loss caused by recurrent infundibular adamantinomatous craniopharyngioma. A first surgical attempt to reduce the cystic portion of the tumor compressing the optic pathway failed. Due to rapid worsening of visual function, adjuvant therapy with bevacizumab was initiated before radiotherapy.

RESULTS

Neuroradiological and ophthalmological follow-up showed a decrease in tumor volume and improvement in visual function as early as 6 weeks after commencing therapy. These results were confirmed 3 months after commencement of chemotherapy. Radiotherapy was scheduled for long-term tumor control.

CONCLUSIONS

To the best of our knowledge, our case is the first in the literature in which targeted therapy using anti-VEGF was successfully used as a single agent to treat adamantinomatous craniopharyngioma, with favorable outcome in terms of tumor shrinkage and clinical improvement. These preliminary results may open new perspectives for the management of adamantinomatous craniopharyngioma. Validation of this approach requires additional clinical evidence.

Correlations between the expression of molecules in the TGF-β signaling pathway and clinical factors in adamantinomatous craniopharyngiomas

Objective

To investigate the clinical and pathological factors associated with preoperative hypothalamus invasion and postoperative outcomes of adamantinomatous craniopharyngiomas (ACPs) after the expanded endonasal approach (EEA) resection.

Methods

Ninety-three specimens of ACPs, consisting of 71 primary and 22 recurrent tumors, were investigated for the expression of TGF-β1, SMAD2, SMAD3, and β-catenin by immunohistochemistry staining. The clinical information of relevant patients, including the extent of resection, hypothalamus invasion, endocrinopathy, complications, and prognosis, was reviewed. The relationships between the expression of these immunopathological markers and clinical factors were analyzed.

Results

Endocrinological dysfunctions were more common in recurrent patients and primary patients with hypothalamus invasion in the comparisons. For recurrent patients, the rate of gross total resection (GTR) was significantly lower than for primary patients (63.6% vs. 90.1%, P = 0.007). According to radiological and intraoperative findings, invasive ACPs (IACPs) included 48 (67.6%) cases in primary tumors. The expression of TGF-β1 and β-catenin was significantly higher in recurrent tumors (P = 0.021 and P = 0.018, respectively) and IACPs (P = 0.008 and P = 0.004, respectively). The expression level of TGF-β1 was associated with hypothalamus involvement (Puget grade, P = 0.05; Vile grade, P = 0.002), postoperative endocrinopathy (P = 0.01), and pituitary stalk preservation (P = 0.008) in primary patients. In addition, the extent of resection, treatment history, hypothalamic invasion, and level of TGF-β1 expression had significant influences on tumor recurrence/progression after surgery separately.

Conclusion

Our study demonstrated the potential role of TGF-β1 in the regulation of hypothalamus invasion in ACPs and the prediction of prognosis after EEA surgery. The TGF-β signaling pathway may represent a crucial mechanism in the aggressive behavior and progression of ACPs.

Craniopharyngioma-An update on metabolic and cognitive complications and new therapy

Craniopharyngiomas (CPs) are rare primary brain epithelial tumors arising in the suprasellar region from remnants of Rathke's pouch. About 50% originate at the level of the third ventricle floor, including the hypothalamus (HT). CPs are characterized by a low proliferation rate and symptoms due to mass effect and local infiltration and are managed primarily with surgery and radiotherapy. Gross total removal of a CP will reduce the recurrence rate but increases the risk of HT damage. Today, subtotal resection is the goal and will reduce the risk of HT damage. There are two histological subtypes of CP-adamantinomatous (ACP) and papillary CP (PCP)-that differ in their genesis and age distribution. ACPs are driven by somatic mutations in CTNNB1 gene (encoding β-catenin), and PCPs frequently harbor somatic BRAF V600E mutations. There are also two phenotypes of outcome, the one with a rather good outcome without HT damage and the other with HT damage where recurrent operation with additional cranial radiotherapy results in HT obesity (HO), affecting psychosocial life and cognitive dysfunction. The group with HO suffers from metabolic syndrome, lower basal metabolic rate, and leptin and insulin resistances. There is currently no successful treatment for HO. The group with HT damage suffers from cognitive dysfunction with attention deficits, impaired episodic memory, and processing speed. Diffusion tensor imaging has shown significant microstructural white matter alteration in several areas important for cognition. Recently, complete or partial tumor response was shown to targeted therapy, with BRAF and Mekinist inhibitors for PCPs with BRAF V600E mutation.

Nuclear translocation of beta catenin in patients with Rathke cleft cysts-clinical and imaging characteristics and risk of recurrence

PURPOSE

Although Rathke cleft cysts (RCC) are benign lesions of the sellar region, recurrence is frequent after surgical treatment. Nuclear translocation of ß-catenin (NTßC), a key effector of the wnt-signaling pathway that is responsible for cell renewal, has been shown to act as a proto-oncogene and is considered to be a potential risk factor for increased recurrence in RCC. In this study, we analyzed a surgically treated cohort into patients with and without NTßC expression in order to identify clinical and imaging differences and further evaluate the risk of recurrence.

METHODS

Patients with resection of RCC between 04/2001 and 11/2020 were included. Histological specimens were immunohistochemically stained for ß-catenin. Study endpoints were time to cyst recurrence (TTR) and functional outcome. Functional outcome included ophthalmological and endocrinological data. Furthermore, MRI data were assessed.

RESULTS

Seventy-three patients (median age 42.3 years) with RCC underwent mainly transsphenoidal cyst resection (95.9%), 4.1% via transcranial approach. Immunohistochemical staining for ß-catenin was feasible in 61/73 (83.6%) patients, with nuclear translocation detected in 13/61 cases (21.3%). Patients with and without NTßC were equally likely to present with endocrine dysfunction before surgery (p = 0.49). Postoperative new hypopituitarism occurred in 14/73 (19.2%) patients. Preoperative visual impairment was equal in both groups (p = 0.52). Vision improved in 8/21 (33.3%) patients and visual field deficits in 22/34 (64.7%) after surgery. There was no difference in visual and perimetric outcome between patients with and without NTßC (p = 0.45 and p = 0.23, respectively). On preoperative MRI, cyst volume (9.9 vs. 8.2 cm3; p = 0.4) and evidence of hemorrhage (30.8% vs. 35.4%; p = 0.99) were equal and postoperative cyst volume decreased significantly in both groups (0.7 vs. 0.5 cm3; p < 0.0001 each). Cyst progression occurred in 13/73 (17.8%) patients after 39.3 ± 60.3 months. Cyst drainage with partial removal of the cyst wall resulted in improved recurrence-free survival without increasing the risk of complications compared with cyst fenestration alone. Patients with postoperative diabetes insipidus had an increased risk for recurrence according to multivariate analysis (p = 0.005). NTßC was evident in 4/15 patients (26.7%) and was not associated with a higher risk for recurrence (p = 0.67).

CONCLUSION

Transnasal transsphenoidal cyst drainage with partial removal of the cyst wall reduces the risk of recurrence without increasing the risk of complications compared with fenestration of the cyst alone. Patients with postoperative diabetes insipidus seem to have an increased risk for recurrence. In contrast, NTßC was not associated with a higher risk of recurrence and did not provide stratification for clinically distinct patients.

Differential expression levels of β-catenin are associated with invasive behavior of both functional and non-functional pituitary neuroendocrine tumor (PitNET)

BACKGROUND

Although research continues to elucidate the molecular mechanism underlying pituitary tumor pathogenesis, limited information is available on the potential role and expression profile of β-catenin in functional and non-functional pituitary neuroendocrine tumors (PitNETs).

METHODS AND RESULTS

In the current study, 104 pituitary samples (tumors and cadaveric healthy pituitary tissues) were included and the gene and protein expression levels of β-catenin were assessed by Real-Time PCR and immunohistochemistry, respectively. The correlation between expression level of β-catenin and tumor invasive feature and size as well as patient age, gender, and hormonal level was measured. The data showed that PitNET samples expressed higher levels of the β-catenin gene and protein compared to healthy pituitary tissues. Although there was no difference in β-catenin expression level between non-functioning (NF-PitNETs) and growth hormone-producing tumors (GH-PitNETs), both tumor types showed significantly elevated β-catenin levels compared to healthy pituitary tissues. The high level of β-catenin in the invasive functional and non-functional tumors is indicative of the association of β-catenin with PitNETs invasion. The expression pattern of the β-catenin gene and protein was consistently and significantly associated with these tumor types. The correlation between β-catenin and insulin-like growth factor 1 (IGF-1) in GH-PitNETs indicates the potential relevance of β-catenin and IGF-1 for GH-PitNETs.

CONCLUSIONS

The simultaneous increase in the expression of β-catenin gene and protein level in PitNET tissues and their relationship to the tumor severity indicates the possible contributing role of β-catenin and its underlying signaling mediators in PitNET pathogenesis.

The molecular pathogenesis of craniopharyngiomas

Research from the last 20 years has provided important insights into the molecular pathogenesis of craniopharyngiomas (CPs). Besides the well-known clinical and histological differences between the subtypes of CPs, adamantinomatous (ACP) and papillary (PCP) craniopharyngiomas, other molecular differences have been identified, further elucidating pathways related to the origin and development of such tumors. The present minireview assesses current knowledge on embryogenesis and the genetic, epigenetic, transcriptomic, and signaling pathways involved in the ACP and PCP subtypes, revealing the similarities and differences in their profiles. ACP and PCP subtypes can be identified by the presence of mutations in CTNNB1 and BRAF genes, with prevalence around 60% and 90%, respectively. Therefore, β-catenin accumulates in the nucleus-cytoplasm of cell clusters in ACPs and, in PCPs, cell immunostaining with specific antibody against the V600E-mutated protein can be seen. Distinct patterns of DNA methylation further differentiate ACPs and PCPs. In addition, research on genetic and epigenetic changes and tumor microenvironment specificities have further clarified the development and progression of the disease. No relevant transcriptional differences in ACPs have emerged between children and adults. In conclusion, ACPs and PCPs present diverse genetic signatures and each subtype is associated with specific signaling pathways. A better understanding of the pathways related to the growth of such tumors is paramount for the development of novel targeted therapeutic agents.

Molecular biological features of cyst wall of adamantinomatous craniopharyngioma

The molecular biological differences between cyst walls and those in solid bodies are the foundation of the outcomes. In this study, the CTNNB1 mutations were confirmed by DNAsequencing; CTNNB1 expression levels were detected by PCR; the differences between solid bodies and cyst walls in proliferative capacity and tumor stem cell niches were assessed by immunohistochemistry; the effect of the residual cyst wall on recurrence was assessed by follow-up. Mutations in the CTNNB1 in the cyst wall and the solid body were identical in each case. No differences were found in the transcriptional level of CTNNB1 between the cyst walls and the solid bodies (P = 0.7619). The cyst wall showed a pathological structure similar to the solid body. Proliferative capacity of cyst walls was stronger than that of solid body (P = 0.0021), and β-catenin nuclear positive cells (cell clusters) in cyst walls were more than that in solid tumor (P = 0.0002). The retrospective 45 ACPs showed residual cyst wall was significantly associated with tumor recurrence or regrowth (P = 0.0176). Kaplan-Meier analysis showed there was a significant difference in the prognosis between GTR and STR (P < 0.0001).The cyst wall of ACP contained more tumor stem cell niches which could lead to the recurrence. According to the above-mentioned, a special attention to the management of the cyst wall should be paid.

Retrospective dataset and survey analyses identify gaps in data collection for craniopharyngioma and priorities of patients and families affected by the disease

INTRODUCTION

Craniopharyngioma is a rare, low-grade tumor located in the suprasellar region of the brain, near critical structures like the pituitary gland. Here, we concurrently investigate the status of clinical and genomic data in a retrospective craniopharyngioma cohort and survey-based data to better understand patient-relevant outcomes associated with existing therapies and provide a foundation to inform new treatment strategies.

METHODS

Clinical, genomic, and outcome data for a retrospective cohort of patients with craniopharyngioma were collected and reviewed through the Children's Brain Tumor Network (CBTN) database. An anonymous survey was distributed to patients and families with a diagnosis of craniopharyngioma to understand their experiences throughout diagnosis and treatment.

RESULTS

The CBTN repository revealed a large proportion of patients (40 - 70%) with specimens that are available for sequencing but lacked relevant quality of life (QoL) and functional outcomes. Frequencies of reported patient comorbidities ranged from 20-35%, which is significantly lower than historically reported. Survey results from 159 patients/families identified differences in treatment considerations at time of diagnosis versus time of recurrence. In retrospective review, patients and families identified preference for therapy that would improve QoL, rather than decrease risk of recurrence (mean 3.9 vs. 4.4 of 5) and identified endocrine issues as having the greatest impact on patients' lives.

CONCLUSIONS

This work highlights the importance of prospective collection of QoL and functional metrics alongside robust clinical and molecular correlates in individuals with craniopharyngioma. Such comprehensive measures will facilitate biologically relevant therapeutic strategies that also prioritize patient needs.

Craniopharyngioma in Pediatrics and Adults

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 β-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.

Phosphorylation of β-catenin at Serine552 correlates with invasion and recurrence of non-functioning pituitary neuroendocrine tumours

Non-functioning pituitary tumours (NF-PitNETs) are common intracranial benign neoplasms that can exhibit aggressive behaviour by invading neighbouring structures and, in some cases, have multiple recurrences. Despite resulting in severe co-morbidities, no predictive biomarkers of recurrence have been identified for NF-PitNETs. In this study we have used high-throughput mass spectrometry-based analysis to examine the phosphorylation pattern of different subsets of NF-PitNETs. Based on histopathological, radiological, surgical and clinical features, we have grouped NF-PitNETs into non-invasive, invasive, and recurrent disease groups. Tumour recurrence was determined based on regular clinical and radiological data of patients for a mean follow-up of 10 years (SD ± 5.4 years). Phosphoproteomic analyses identified a unique phosphopeptide enrichment pattern which correlates with disease recurrence. Candidate phosphorylated proteins were validated in a large cohort of NF-PitNET patients by western blot and immunohistochemistry. We identified a cluster of 22 phosphopeptides upregulated in recurrent NF-PitNETs compared to non-invasive and invasive subgroups. We reveal significant phosphorylation of the β-catenin at Ser552 in recurrent and invasive NF-PitNETs, compared to non-invasive/non-recurrent NF-PitNET subgroup. Moreover, β-catenin pSer552 correlates with the recurrence free survival among 200 patients with NF-PitNET. Together, our results suggest that the phosphorylation status of β-catenin at Ser552 could act as potential biomarker of tumour recurrence in NF-PitNETs.

Telomere length and Wnt/β-catenin pathway in adamantinomatous craniopharyngiomas

OBJECTIVES

To evaluate how telomere length behaves in adamantinomtous craniopharyngioma (aCP) and if it contributes to the pathogenesis of aCPs with and without CTNNB1 mutations.

DESIGN

Retrospective cross-sectional study enrolling 42 aCP patients from 2 tertiary institutions.

METHODS

Clinicopathological features were retrieved from the patient's charts. Fresh frozen tumors were used for RNA and DNA analyses. Telomere length was evaluated by qPCR (T/S ratio). Somatic mutations in TERT promoter (TERTp) and CTNNB1 were detected by Sanger and/or whole-exome sequencing. We performed RNA-Seq to identify differentially expressed genes in aCPs presenting with shorter or longer telomere lengths.

RESULTS

Mutations in CTNNB1 were detected in 29 (69%) tumors. There was higher frequency of CTNNB1 mutations in aCPs from patients diagnosed under the age of 15 years (85% vs 15%; P = 0.04) and a trend to recurrent disease (76% vs 24%; P = 0.1). No mutation was detected in the TERTp region. The telomeres were shorter in CTNNB1-mutated aCPs (0.441, IQR: 0.297-0.597vs 0.607, IQR: 0.445-0.778; P = 0.04), but it was neither associated with clinicopathological features nor with recurrence. RNAseq identified a total of 387 differentially expressed genes, generating two clusters, being one enriched for short telomeres and CTNNB1-mutated aCPs.

CONCLUSIONS: CTNNB1

mutations are more frequent in children and adolescents and appear to associate with progressive disease. CTNNB1-mutated aCPs have shorter telomeres, demonstrating a relationship between the Wnt/β-catenin pathway and telomere biology in the pathogenesis of aCPs.

Xanthogranuloma of the Sellar Region: A Comprehensive Review of Neuroimaging in a Rare Inflammatory Entity

Xanthogranuloma of the sellar region is a rare chronic inflammatory lesion resulting from secondary hemorrhage, inflammation, infarction, and necrosis of an existing Rathke’s cleft cyst, craniopharyngioma, or pituitary adenoma. Sellar xanthogranulomas are challenging to differentiate from other cystic lesions preoperatively due to the lack of characteristic imaging features. We performed a literature overview of the clinical and paraclinical features, treatment options, and long-term outcomes of patients with sellar xanthogranuloma, focusing on the preoperative radiological diagnosis. The hyperintense signal in both T1- and T2-weighted sequences, cystic or partially cystic morphology, ovoid shape, sellar epicenter, intra- and suprasellar location, intratumoral calcifications, linear rim contrast enhancement, and the absence of cavernous sinus invasion suggest xanthogranuloma in the preoperative differential diagnosis. An endoscopic endonasal gross total resection without radiotherapy is the preferred first-line treatment. Given the low rate of recurrence rate and low chance of endocrinological recovery, a mass reduction with decompression of the optic apparatus may represent an appropriate surgical goal. Identifying the xanthogranulomas’ mutational profile could complement histopathological diagnosis and give insight into their histo-pathogenesis. A better preoperative neuroimagistic diagnosis of sellar xanthogranulomas and differentiation from lesions with a poorer prognosis, such as craniopharyngioma, would result in an optimal personalized surgical approach.

Useful diagnostic histogenetic features of ectopic odontogenic ghost cell tumours

BACKGROUND

Ectopic odontogenic tumours are rare and difficult to diagnose. Consequently, they are occasionally misdiagnosed as other tumours and overtreated. Dentinogenic ghost cell tumours (DGCTs) are odontogenic neoplasms characterised by a CTNNB1 mutation, ghost cell appearance, and dentinoid-like calcification. Herein, we present a case of ectopic DGCT on the floor of a patient's mouth, providing reliable clinicopathological and genetic evidence of its odontogenicity for the first time.

CASE PRESENTATION

A 72-year-old man presented with painless sublingual swelling. Imaging revealed a multi-lobulated, solid-cystic mass on the floor of his mouth. Cytological evaluation showed folded epithelial clusters composed of basaloid cells, keratinised material, and calcification. Histological analysis revealed a multi-cystic, cribriform to solid nest, with an odontogenic satellate reticulum-like epithelium, including ghost cells and dentinoid matrix deposition. Immunohistochemical analysis found that CK19, CK5/6, bcl-2, and p63 were diffuse positive, β-catenin was focal positive in the nuclei, and the cells in the dentinoid matrix were positive for DMP1. The CTNTTB1 mutation was detected, leading to the final diagnosis of ectopic DGCT. There was no recurrence during the 6-month follow-up.

CONCLUSIONS

Overall, we have presented a comprehensive clinical overview of DGCT and identified its pathological and genetic features. This report will aid in the recognition of this rare disease in the future and help to avoid misdiagnosis and overtreatment.

Parafoveal and peripapillary vessel density in pediatric and juvenile craniopharyngioma patients

We assessed the retinal microvascular alterations detected by optical coherence tomography angiography (OCT-A) in pediatric and juvenile craniopharyngioma (CP) patients with chiasmal compression. We included 15 eyes of 15 pediatric or juvenile CP patients and 18 eyes of 18 healthy subjects. The evaluation of vessel density from the superficial retinal capillary plexus (SRCP), the deep retinal capillary plexus, and the radial peripapillary capillary (RPC) segments was obtained by OCT-A. The association between vessel density measures and functional and structural measurements was also analyzed. There were significant reductions in the nasal sector of the SRCP (p < 0.0001) and all sectors of the RPC segment vessel density (nasal, temporal, and superior; p < 0.0001, inferior; p = 0.0015) in CP patients postoperatively compared to the healthy subjects. The peripapillary retinal nerve fiber layer (r = 0.6602, p = 0.0074) and ganglion cell-inner plexiform layer thicknesses (r = 0.7532, p = 0.0030) were associated with RPC segment vessel density. Visual acuity (r = − 0.5517, p = 0.0330) and temporal visual field sensitivity loss (r = 0.5394, p = 0.0465) showed an association with SRCP vessel density. In pediatric and juvenile patients with CP, parafoveal and peripapillary vascular changes following chiasmal compression were observed. The changes in vascular structures were closely related to structural and functional outcomes.

Current Advances in the Management of Adult Craniopharyngiomas

Craniopharyngiomas (CPs) are slow growing, histologically benign intracranial tumors located in the sellar–suprasellar region. Although known to have low mortality, their location and relationship to the adjacent neural structures results in patients having significant neurologic, endocrine, and visual comorbidities. The invasive nature of this tumor makes complete resection a challenge and contributes to its recurrence. Additionally, these tumors are bimodally distributed, being treated with surgery, and are followed by other adjuncts, such as focused radiation therapy, e.g., Gamma knife. Advances in surgical techniques, imaging tools, and instrumentations have resulted in the evolution of surgery using endoscopic techniques, with residual components being treated by radiotherapy to target the residual tumor. Advances in molecular biology have elucidated the main pathways involved in tumor development and recurrence, but presently, no other treatments are offered to patients, besides surgery, radiation, and endocrine management, as the disease and tumor evolve. We review the contemporary management of these tumors, from the evolution of surgical treatments, utilizing standard open microscopic approaches to the more recent endoscopic surgery, and discuss the current recommendations for care of these patients. We discuss the developments in radiation therapy, such as radiosurgery, being used as treatment strategies for craniopharyngioma, highlighting their beneficial effects on tumor resections while decreasing the rates of adverse outcomes. We also outline the recent chemotherapy modalities, which help control tumor growth, and the immune landscape on craniopharyngiomas that allow the development of novel immunotherapies.

Skull Base Tumors: Neuropathology and Clinical Implications

Tumors that arise in and around the skull base comprise a wide range of common and rare entities. Recent studies have advanced our understanding of their pathogenesis, which in some cases, have significantly influenced clinical practice. The genotype of meningiomas is strongly associated with their phenotype, including histologic subtype and tumor location, and clinical outcome. A single molecular alteration, NAB2-STAT6 fusion, has redefined the category of solitary fibrous tumors to include the previous entity hemangiopericytomas. Schwannomas, both sporadic and familial, are characterized by near ubiquitous alterations in NF2 , with additional mutations in SMARCB1 or LZTR1 in schwannomatosis. In pituitary adenohypophyseal tumors, cell lineage transcription factors such as SF-1, T-PIT, and PIT-1 are now essential for classification, providing a more rigorous taxonomy for tumors that were previously considered null cell adenomas. The pituicyte lineage transcription factor TTF-1 defines neurohypophyseal tumors, which may represent a single nosological entity with a spectrum of morphologic manifestations (ie, granular cell tumor, pituicytoma, and spindle cell oncocytoma). Likewise, the notochord cell lineage transcription factor brachyury defines chordoma, discriminating them from chondrosarcomas. The identification of nonoverlapping genetic drivers of adamantinomatous craniopharyngiomas and papillary craniopharyngiomas indicates that these are distinct tumor entities and has led to successful targeted treatment of papillary craniopharyngiomas using BRAF and/or mitogen-activated protein kinase inhibitors. Similarly, dramatic therapeutic responses have been achieved in patients with Langerhans cell histiocytosis, both with BRAF -mutant and BRAF -wildtype tumors. Familiarity with the pathology of skull base tumors, their natural history, and molecular features is essential for optimizing patient care.

Medical Therapy for Craniopharyngiomas

Craniopharyngiomas are rare benign neoplasms presenting in two different types, adamantinomatous (ACP) or papillary (PCP), which are molecularly and clinically distinct. Traditional treatment includes surgical resection and radiotherapy, which are accompanied by a number of debilitating complications because of the tumours' proximity to important brain structures. Recent advances in the understanding of molecular pathogenesis of craniopharyngiomas have opened horizons to medical therapeutic options. ACPs are mainly characterized by mutations of β-catenin, which activate Wingless/Int (Wnt), and alter the mitogen extracellular kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway, as well as inflammatory, cellular senescence, programmed cell death and sonic hedgehog (SHH) pathways. PCPs are mainly characterized by Ras/Raf/MEK/ERK pathway activation secondary to BRAF-V600E mutations. MEK inhibitors, such as binimetinib, or anti-inflammatory mediators, such as tocilizumab or interferon, have been administered to patients with ACP and the efficacy is mostly favourable. On the other hand, BRAF inhibitors, such as dabrafenib or vemurafenib, either alone or in combination with the MEK inhibitors trametinib and cobimetinib, have been administered to patients with PCP resulting in favourable responses. A number of ongoing trials will shed light on schemes, doses, combined treatments and safety issues of the new molecular-targeted treatments, changing the management of patients with craniopharyngiomas by launching the era of personalized medicine in these rare neoplasms. We conducted a systematic review to identify case series or case reports with patients currently treated with systemic medical therapy.

Characterization of novel CTNNB1 mutation in Craniopharyngioma by whole-genome sequencing

Background

Craniopharyngioma (CP) is rare histologically benign but clinically challenging tumor because of its intimate relationship with the critical structure in the central brain. CP can be divided into two major histologic subtypes: adamantinomatous-type CP (ACP) and papillary-type CP (PCP). Although some genetic aberrations for both categories have been revealed in previous studies, the complete spectrum of genetic changes of this tumor remains unknown.

Methods

In this study, we conducted whole genome sequencing (WGS) on twenty-six CPs including 16 ACPs and 10 PCPs together with their matched blood samples. Somatic variants (SNVs, InDels, SVs and CNVs) were identified and mutational signatures were characterized for each patient. We investigated the impact of a novel CTNNB1 mutant on its protein stability, ubiquitination and Wnt pathway activity. Cell proliferation ability of the CTNNB1 mutant in ACP primary cells was additionally analyzed by CCK8 and colony formation assays.

Results

We found that CPs had showed less complexity with fewer somatic mutations compared with malignant tumors. Moreover, mutations in CTNNB1 (68.75% of ACP) and BRAF V600E (70.00% of PCP) are mutually exclusive in ACP and PCP, consolidating that the driving roles of these two genes in ACP and PCP, respectively. A novel mutation in the exon 3 of CTNNB1 which compromised both a transversion and in-frame deletion was identified in ACP. This mutation was experimentally validated to confer β-catenin increased stability by inhibiting its ubiquitination, thus activating Wnt-signaling pathway and promoting cell proliferation.

Conclusions

Whole genome landscape for CP was revealed by WGS analysis, and a novel mutation in the exon 3 of CTNNB1 was identified. This novel mutation activates Wnt-signaling pathway through increasing the stability of β-catenin. Our findings provided us with more comprehensive insight into the spectrum of genetic alterations in CP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-021-01468-7.

Status Quo and Research Trends of Craniopharyngioma Research: A 10-Year Bibliometric Analyses (From 2011 to 2020)

Background

Craniopharyngioma (CP) is a challenging intracranial tumor due to its special hypothalamus-pituitary location. Each patient with CP should be evaluated and treated separately. Exploring novel methods of automatized analysis of data for gaining knowledge on any medical field is an encouraging task, particularly in such an extremely challenging tumor as CP. We aim to summary the situations, investigate the research trends and evaluate research hotspots using bibliometric analysis for the CP research.

Methods

We extracted all the CP-related literatures from 2011 to 2020 from the Web of Science database. An Online analysis platform of literature metrology (Bibliometric), BICOMB, gCLUTO and CiteSpace softwares were used to do bibliometric analysis. As a supplement, we also analyzed the top 100 cited case reports with particular and certainly infrequent information to improve the analysis.

Results

According to our retrieval strategy, we found a total of 1262 CP-related literatures. The United States has maintained a leading position in global CP research, followed by China and Germany. Among institutions, Capital Med Univ, St Jude Childrens Res Hosp and Southern Med Univ rank in the top 3 in terms of the number of articles published. “WORLD NEUROSURGERY” is the most popular journal for CP-related research. Moreover, MULLER HL, MERCHANT TE, QI ST and others have made great achievements in the study of CP. Finally, we did biclustering analysis on keywords and identified 4 CP research hotspot clusters.

Conclusions

Our research provides a comprehensive analysis of the scientific progress of CP in the past 10 years, and insight into the development of CP research field, highlight research trends over time, and help identify valuable future directions.

Childhood-onset Craniopharyngioma

Craniopharyngiomas are rare embryonic malformational tumors of the sellar/parasellar region, classified by the World Health Organization (WHO) as tumors with low-grade malignancy (WHO I). The childhood adamantinomatous subtype of craniopharyngioma is usually cystic with calcified areas. At the time of diagnosis, hypothalamic/pituitary deficits, visual disturbances, and increased intracranial pressure are major symptoms. The treatment of choice in case of favorable tumor location (without hypothalamic involvement) is complete resection. It is important to ensure that optical and hypothalamic functionality are preserved. In case of unfavorable tumor location, that is with hypothalamic involvement, a hypothalamus-sparing surgical strategy with subsequent local irradiation of residual tumor is recommended. In the further course of the disease, recurrences and progression often occur. Nevertheless, overall survival rates are high at 92%. Severe impairment of quality of life and comorbidities such as metabolic syndrome, hypothalamic obesity, and neurological consequences can be observed in patients with disease- and/or treatment-related lesions of hypothalamic structures. Childhood-onset craniopharyngioma frequently manifests as a chronic disease so that patients require lifelong, continuous care by experienced multidisciplinary teams to manage clinical and quality of life consequences. For this review, a search for original articles and reviews published between 1986 and 2020 was performed in Pubmed, Science Citation Index Expanded, EMBASE, and Scopus. The search terms used were "craniopharyngioma, hypothalamus, pituitary obesity, irradiation, neurosurgery.

Perioperative Complications in Endoscopic Endonasal versus Transcranial Resections of Adult Craniopharyngiomas

BACKGROUND

Adult craniopharyngiomas are low-grade tumors of the pituitary infundibulum that can be locally aggressive and frequently present with profound visual deficits and endocrinopathies. Surgical resection remains the preferred initial treatment for these lesions, and recently endoscopic endonasal approaches (EEAs) have become increasingly used. However, minimal data exist comparing these techniques with traditional transcranial (TC) methods. The purpose of this study was to evaluate perioperative differences in EEA and TC approaches for adult craniopharyngiomas over the past several decades.

METHODS

Craniopharyngioma surgeries in the Nationwide Inpatient Sample from 1998 to 2014 were identified. Complication rates, mortality rates, and annual treatment trends were stratified by procedure. Annual caseload was assessed with linear regression, and multivariate logistic regression models were created to determine predictors of inpatient mortality and perioperative complications.

RESULTS

From 1998-2014, a significant increase in EEAs for craniopharyngiomas (+4.36/year, r² = 0.80, P < 0.0001) was observed. In contrast, no increase in TC surgeries for these lesions was seen. In multivariate analysis, EEAs were more likely to experience postoperative cerebrospinal fluid leak (odds ratio = 2.61, P < 0.0001). However, EEAs were protective against all other perioperative complications including diabetes insipidus, panhypopituitarism, visual impairment, and even mortality (odds ratio = 0.41, P = 0.0007).

CONCLUSIONS

Over the past several decades, utilization of EEAs to resect adult craniopharyngiomas has increased. EEAs appear to be associated with lower rates of perioperative mortality and complications. However, long-term, prospective studies controlling for tumor size, location, and preoperative symptomatology are needed to determine when one approach should be used preferentially over the other.

Gliomas, germ cell tumors, and craniopharyngioma

This report summarizes the current multimodality treatment approaches for children with low- and high-grade gliomas, germinoma, and nongerminomatous germ cell tumors, and craniopharyngiomas used in the Children's Oncology Group (COG) and the International Society of Pediatric Oncology (SIOP). Treatment recommendations are provided in the context of historical approaches regarding the roles of surgery, radiation, and chemotherapy. Future research strategies for these tumors in both COG and SIOP are also discussed.

Adamantinomatous craniopharyngioma as a model to understand paracrine and senescence-induced tumourigenesis

Cellular senescence is a process that can prevent tumour development in a cell autonomous manner by imposing a stable cell cycle arrest after oncogene activation. Paradoxically, senescence can also promote tumour growth cell non-autonomously by creating a permissive tumour microenvironment that fuels tumour initiation, progression to malignancy and metastasis. In a pituitary tumour known as adamantinomatous craniopharyngioma (ACP), cells that carry oncogenic β-catenin mutations and overactivate the WNT signalling pathway form cell clusters that become senescent and activate a senescence-associated secretory phenotype (SASP). Research in mouse models of ACP has provided insights into the function of the senescent cell clusters and revealed a critical role for SASP-mediated activities in paracrine tumour initiation. In this review, we first discuss this research on ACP and subsequently explore the theme of paracrine tumourigenesis in other tumour models available in the literature. Evidence is accumulating supporting the notion that paracrine signalling brought about by senescent cells may underlie tumourigenesis across different tumours and cancer models.

[The 2017 WHO classification of pituitary tumors]

The 2017 WHO classification of pituitary tumors is still based on structural analyses and expression of various pituitary hormones. Three innovations have to be considered: (1) The expression of pituitary transcription factors Pit‑1, T‑Pit and SF‑1. (2) The term "atypical adenoma" was replaced by "aggressive adenoma". (3) The three tumor types of the neurohypophysis (pituicytoma, spindle cell oncocytoma, granular cell tumor) are defined by their common expression of TTF‑1. Craniophyryngiomas are identified as adamantinomatous type by focal nuclear expression of β‑catenin or as papillary type by demonstration of BRAF V600E mutation. Further primary tumors of the pituitary are extremely rare. These and also the other tumors of the sellar region can be structurally very similar to pituitary adenomas but can be-nearly without exception-differentiated by immunocytochemistry.

Genomics and Epigenomics of Pituitary Tumors: What Do Pathologists Need to Know?

Molecular pathology has advanced our understanding of many tumors and offers opportunities to identify novel therapies. In the pituitary, the field has uncovered several genetic mutations that predispose to pituitary neuroendocrine tumor (PitNET) development, including MEN1, CDKN1B, PRKRIα, AIP, GPR101, and other more rare events; however, these genes are only rarely mutated in sporadic PitNETs. Recurrent genetic events in sporadic PitNETs include GNAS mutations in a subset of somatotroph tumors and ubiquitin-specific peptidase mutations (e.g., USP8, USP48) in some corticotroph tumors; to date, neither of these has resulted in altered management, and instead, the prognosis and management of PitNETs still rely more on cell type and subtype as well as local growth that determines surgical resectability. In contrast, craniopharyngiomas have either CTNNB1 or BRAF^V600E mutations that correlate with adamantinomatous or papillary morphology, respectively; the latter offers the opportunity for targeted therapy. DICER1 mutations are found in patients with pituitary blastoma. Epigenetic changes are implicated in the pathogenesis of the more common sporadic pituitary neoplasms including the majority of PitNETs and tumors of pituicytes.

Prediction of CTNNB1 Mutation Status in Pediatric Cystic Adamantinomatous Craniopharyngioma by Using Preoperative Magnetic Resonance Imaging Manifestation

OBJECTIVE

CTNNB1-targeted inhibitor is demonstrated to be an effective neoadjuvant therapy in adamantinomatous craniopharyngioma (ACP) patients and cystic degeneration is a canonical sign of pediatric ACP. This study aimed to investigate the relationship between the cystic performances and CTNNB1 mutation (CTNNB1 MUT) status so as to analyze the possible diagnostic criteria of CTNNB1 MUT in pediatric cystic ACP (PCACP).

METHODS

Patient's population, clinical characteristics, tissue samples and MRI data were collected and summarized in PCACP patients. The results were compared between CTNNB1 MUT and CTNNB1 wild-type (WT) groups according to the Sanger sequencing. MRI features of the cyst were also recorded. The receiving operating characteristic (ROC) curve analysis was applied to evaluate the differential diagnostic value.

RESULTS

19 of the 61 patients manifested CTNNB1 MUT PCACP and 42 patients were CTNNB1 WT PCACP. Multiple cysts, irregular shape of cyst, hypo-intense interior signal of cyst on non-contrast T1W1, compression with optic chiasm and pituitary stalk and enhancement signal of cystic wall have been demonstrated in CTNNB1 MUT PCACP patients on MRI. Only the Area under the curve (AUC) values of quantity of cyst, shape of cyst and interior signal of cyst on non-contrast T1W1 were over 0.7. For criteria based on the combination of the 6 characteristic features, the AUC value was 0.928.

CONCLUSION

Preoperative MRI may provide an effective value in predicting PCACP patients with CTNNB1 MUT and offer potential evidence for preoperative management with molecular targeted agents.

A Rare Case of Recurrent Pituitary Collision Tumors

Pituitary collision tumors are sporadically reported and rare. We present a case of pituitary collision tumors with nonfunctioning pituitary adenoma (NFPA) and craniopharyngioma. In order to look for any common activated pathway, we examined WNT/β-CATENIN signaling activation, known to be involved in tumorigenesis in both craniopharyngioma and NFPA. We found nuclear accumulation of β-CATENIN protein and expression of LEF1 protein, markers of active β-CATENIN signaling in the craniopharyngioma but not in the pituitary adenomas. In our case, the NFPA is invasive macroadenoma, which is a frequently identified type of pituitary adenoma in collision tumor cases. Recurrence of this tumor was first observed after 8 years of follow-up. Based on this case, we suggest that pituitary collision tumors require long-term follow-up.

Biological Behaviour of Craniopharyngiomas

Jakob Erdheim (1874-1937) first described craniopharyn-giomas (CPs) as "hypophyseal duct tumours" and postulated the existence of two tumour types based on their histological features: (1) an aggressive type showing similarities to adamantinomas (tumours of the jaw) and (2) a more benign form characterised by the presence of papillary structures. More than a century later, these initial observations have been confirmed; based on their distinct genetic, epigenetic, and histological features, the WHO classifies CPs into two types: adamantinomatous CPs (ACPs) and papillary CPs (PCPs). Considerable knowledge has been generated on the biology of CPs in the last 20 years. Mutations in CTNNB1 (encoding β-catenin) are prevalent in ACP, whilst PCPs frequently harbour mutations in BRAF (p.BRAF-V600E). The consequence of these mutations is the activation of either the WNT/β-catenin (ACP) or the MAPK/ERK (PCP) pathway. Murine models support a critical role for these mutations in tumour formation and have provided important insights into tumour pathogenesis, mostly in ACP. A critical role for cellular senescence has been uncovered in murine models of ACP with relevance to human tumours. Several gene profiling studies of human and murine ACP tumours have identified potential targetable pathways, and novel therapeutic agents are being used in clinical and pre-clinical research, in some cases with excellent results. In this review, we will present the accumulated knowledge on the biological features of these tumours and summarise how these advances are being translated into potential novel treatments.

Outcome of Chinese children with craniopharyngioma: a 20-year population-based study by the Hong Kong Pediatric Hematology/Oncology Study Group

PURPOSE

Craniopharyngioma is a rare low-grade neoplasm in children. Tumor progression occurs frequently, and survivors are at risk of long-term disease and treatment-related morbidities. We reviewed the population-based experience of managing pediatric craniopharyngioma in Hong Kong.

METHODS

The Hong Kong Pediatric Hematology/Oncology Study Group database was interrogated for patients with craniopharyngioma younger than 18 years between 1999 and 2018. Patient demographics, clinical characteristics, outcomes, and long-term morbidities were summarized.

RESULTS

Twenty-eight patients with craniopharyngioma were included (approximate incidence of 1.1 per 1,000,000 individuals). The treatment approaches were heterogeneous and included surgery only, surgery with adjuvant radiation, and surgery with intracystic interferon. With a median follow-up of 6.1 years, 12 (43%) patients experienced disease progression, and 3 patients died of progression, postoperative complication, and gastrointestinal bleeding. The 5-year progression-free survival (PFS) and overall survival (OS) rates were 56.8% (± 10.0%) and 92.0% (± 5.4%), respectively. The 10-year PFS and OS rates were 37.3% (± 11.4) and 92.0% (± 5.4%), respectively. Patients receiving treatment in a high-volume center had significantly better outcomes than did those treated at other centers (PFS, p = 0.007; OS, p = 0.029). Period of diagnosis, sex, age at diagnosis, greatest tumor dimension, extent of resection, and radiotherapy use did not significantly affect patient survival. Long-term visual impairment (60%) and endocrinopathies (92%) were common.

CONCLUSION

Prognosis of pediatric craniopharyngioma in Hong Kong compares unfavorably with published reports. Centralization and standardization of treatment may prove valuable in mitigating patient outcomes.

The Inflammatory Milieu of Adamantinomatous Craniopharyngioma and Its Implications for Treatment

Pediatric Adamantinomatous Craniopharyngiomas (ACPs) are histologically benign brain tumors that often follow an aggressive clinical course. Their suprasellar location leaves them in close proximity to critical neurological and vascular structures and often results in significant neuroendocrine morbidity. Current treatment paradigms, involving surgical resection and radiotherapy, confer significant morbidity to patients and there is an obvious need to discover effective and safe alternative treatments. Recent years have witnessed significant efforts to fully detail the genomic, transcriptomic and proteomic make-up of these tumors, in an attempt to identify potential therapeutic targets. These studies have resulted in ever mounting evidence that inflammatory processes and the immune response play a critical role in the pathogenesis of both the solid and cystic portion of ACPs. Several inflammatory and immune markers have been identified in both the cyst fluid and solid tumor tissue of ACP. Due to the existence of effective agents that target them, IL-6 and immune checkpoint inhibitors seem to present the most likely immediate candidates for clinical trials of targeted immune-related therapy in ACP. If effective, such agents may result in a paradigm shift in treatment that ultimately reduces morbidity and results in better outcomes for our patients.

The Diagnosis and Treatment of Craniopharyngioma

Craniopharyngioma (CP) is a rare embryonic malformation of the sellar/parasellar region with a low histological grade. Clinical manifestations are related to hypothalamic/pituitary deficiencies, visual impairment, and increased intracranial pressure. Recent insight into the molecular pathogenesis of CP opens new perspectives on targeted therapy in papillary CP harboring BRAF-V600E mutations. Further research to elucidate pathogenic mechanisms and hopefully prevent hypothalamic involvement of CP is warranted. If the tumor is favorably localized, the therapy of choice is complete resection, with care taken to preserve the optical and hypothalamic functions. In patients with unfavorable tumor localization (i.e., hypothalamic involvement), the recommended therapy is a limited hypothalamus-sparing surgical strategy followed by local irradiation. Surgical treatment strategies should be based on a multidisciplinary approach involving experienced teams. Centralizing the treatment of CP in experienced "centers of excellence" and multicenter-based networks for reference assessments should be considered to assure a high standard of treatment quality. CP recurrence and progression are frequent. Irradiation has proven effective in reducing recurrences and progression. Proton beam therapy, available in a wider range in the near future, will help to avoid radio-oncological side effects. Anatomical involvement and/or surgical lesions of posterior hypothalamic areas can result in serious sequelae that compromise quality of life (QoL), such as hypothalamic obesity and psychopathological symptoms. Novel insights into neuropsychological sequelae after CP occurrence should be the basis for the development of therapeutic neuropsychological interventions. CP should be managed as a frequently chronic disease, providing ongoing care of pediatric and adult patients' clinical and QoL consequences by experienced multidisciplinary teams.

Diagnosis, Background, and Treatment of Hypothalamic Damage in Craniopharyngioma

Craniopharyngiomas (CP) are rare brain tumors managed primarily with surgery and radiotherapy. There are 2 phenotypes of CP, i.e., one with a rather good outcome without hypothalamic damage and another with hypothalamic damage. With hypothalamic damage, progressive disease with recurrent operations and additional cranial radiotherapy often result in hypothalamic obesity, an affected psychosocial life, and cognitive dysfunction. The morbidity and mortality are increased for particularly cerebrovascular diseases. Preoperative hypothalamic involvement to predict hypothalamic damage is important for decision making for hypothalamus-sparing surgery. Also a postoperative hypothalamic damage evaluation with the use of hypothalamus volume measurement can predict hypothalamic obesity, which is important for early treatment options. The morbidity of CP includes cognitive dysfunction with attention deficits and impaired episodic memory and processing speed. Again patients with hypothalamic damage are more affected. Treatment options of hypothalamic obesity in the chronic phase are scarce and not convincingly successful. The most optimal situation is to try to hinder or stop the evolution of hypothalamic obesity. Prevention of hypothalamic damage is recommended, with special regard to hypothalamus-sparing therapeutic approaches that respect the integrity of essential nuclei located in both the medial and the posterior hypothalamic areas.

Diagnosis and Treatment of Parasellar Lesions

The parasellar region, located around the sella turcica, is an anatomically complex area representing a crossroads for important adjacent structures. Several lesions, including tumoral, inflammatory vascular, and infectious diseases may affect this area. Although invasive pituitary tumors are the most common neoplasms encountered within the parasellar region, other tumoral (and cystic) lesions can also be detected. Craniopharyngiomas, meningiomas, as well as Rathke's cleft cysts, chordomas, and ectopic pituitary tumors can primarily originate from the parasellar region. Except for hormone-producing ectopic pituitary tumors, signs and symptoms of these lesions are usually nonspecific, due to a mass effect on the surrounding anatomical structures (i.e., headache, visual defects), while a clinically relevant impairment of endocrine function (mainly anterior hypopituitarism and/or diabetes insipidus) can be present if the pituitary gland is displaced or compressed. Differential diagnosis of parasellar lesions mainly relies on magnetic resonance imaging, which should be interpreted by neuroradiologists skilled in base skull imaging. Neurosurgery is the main treatment, alone or in combination with radiotherapy. Of note, recent studies have identified gene mutations or signaling pathway modulators that represent potential candidates for the development of targeted therapies, particularly for craniopharyngiomas and meningiomas. In summary, parasellar lesions still represent a diagnostic and therapeutic challenge. A deeper knowledge of this complex anatomical site, the improvement of imaging tools, as well as novel insights into the pathophysiology of presenting lesions are strongly needed to improve the management of parasellar lesions.

Pediatric craniopharyngioma in association with familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is a cancer predisposition syndrome driven by germline loss-of-function of the APC gene and phenotypically manifests with intestinal polyposis and a variety of extra-intestinal bone and soft tissue tumors. Craniopharyngioma is not a well-described FAP-associated tumor, however, six cases have been reported in adults, all demonstrating ectopic location and adamantinomatous histology. We report the first case of craniopharyngioma associated with FAP in a pediatric patient. A seven-year-old girl who presented with headache and vomiting was found on magnetic resonance imaging to have a suprasellar mass with cystic extension to the pre-pontine space. The tumor represented an adamantinomatous craniopharyngioma (aCP) with nuclear β-catenin expression. Whole exome sequencing confirmed a CTNNB1 activating point mutation and a germline APC frameshift variant. This case represents the first FAP-associated craniopharyngioma in childhood…. expanding our understanding of the molecular underpinnings driving tumorigenesis in this unique patient.

The Medical Therapy of Craniopharyngiomas: The Way Ahead

CONTEXT

Craniopharyngiomas, which are categorized as adamantinomatous (ACPs) or papillary (PCPs), have traditionally been treated with surgery and/or radiotherapy, although when the tumors progress or recur, therapeutic possibilities are very limited. Following recent advances in their molecular pathogenesis, new medical therapeutic options have emerged.

EVIDENCE ACQUISITION

The search strategy that we selected to identify the appropriate evidence involved the following medical subject headings (MeSH) terms: ("Craniopharyngioma" [MeSH] AND "Craniopharyngioma/drug therapy" [MeSH]) NOT ("review" [Publication Type] OR "review literature as topic" [MeSH Terms] OR "review" [All Fields]) AND ("2009/05/01" [PDat]: "2019/04/28" [PDat]).

EVIDENCE SYNTHESIS

Mutations of β-catenin causing Wnt activation with alterations of the MEK/ERK pathway are encountered in the great majority of patients with ACPs; specific alterations also stratify patients to a more aggressive behavior. In most PCPs there is primary activation of the Ras/Raf/MEK/ERK pathway secondary to BRAF-V600E mutations. BRAF inhibitors, such as dabrafenib or vemurafenib, either alone or in combination with the MEK inhibitors trametinib and cobimetinib, have been administered to patients with PCPs producing clinically useful and, in some cases, sustained responses. In contrast to PCPs, drugs targeting β-catenin and its downstream MAPK pathway in ACPs have so far only been used in in vitro studies, but there appear to be promising new targets clinically.

CONCLUSIONS

The identification of specific genetic alterations in patients with craniopharyngiomas has expanded the therapeutic options, providing evidence for a customized approach using newer molecular agents. More studies including a larger number of carefully selected patients are required to evaluate the response to currently available and evolving agents alone and in combination.

Stem Cells, Self-Renewal, and Lineage Commitment in the Endocrine System

The endocrine system coordinates a wide array of body functions mainly through secretion of hormones and their actions on target tissues. Over the last decades, a collective effort between developmental biologists, geneticists, and stem cell biologists has generated a wealth of knowledge related to the contribution of stem/progenitor cells to both organogenesis and self-renewal of endocrine organs. This review provides an up-to-date and comprehensive overview of the role of tissue stem cells in the development and self-renewal of endocrine organs. Pathways governing crucial steps in both development and stemness maintenance, and that are known to be frequently altered in a wide array of endocrine disorders, including cancer, are also described. Crucially, this plethora of information is being channeled into the development of potential new cell-based treatment modalities for endocrine-related illnesses, some of which have made it through clinical trials.

Craniopharyngioma

Craniopharyngiomas are rare malformational tumours of low histological malignancy arising along the craniopharyngeal duct. The two histological subtypes, adamantinomatous craniopharyngioma (ACP) and papillary craniopharyngioma (PCP), differ in genesis and age distribution. ACPs are diagnosed with a bimodal peak of incidence (5-15 years and 45-60 years), whereas PCPs are restricted to adults mainly in the fifth and sixth decades of life. ACPs are driven by somatic mutations in CTNNB1 (encoding β-catenin) that affect β-catenin stability and are predominantly cystic in appearance. PCPs frequently harbour somatic BRAFV600E mutations and are typically solid tumours. Clinical manifestations due to increased intracranial pressure, visual impairment and endocrine deficiencies should prompt imaging investigations, preferentially MRI. Treatment comprises neurosurgery and radiotherapy; intracystic chemotherapy is used in monocystic ACP. Although long-term survival is high, quality of life and neuropsychological function are frequently impaired due to the close anatomical proximity to the optic chiasm, hypothalamus and pituitary gland. Indeed, hypothalamic involvement and treatment-related hypothalamic lesions frequently result in hypothalamic obesity, physical fatigue and psychosocial deficits. Given the rarity of these tumours, efforts to optimize infrastructure and international collaboration should be research priorities.

Pediatric craniopharyngioma

BACKGROUND

Craniopharyngioma has historically been recognized to be a formidable pathology primarily due to its proximity to critical neurovascular structures and the challenging surgical corridors that surgeons have tried to reach this lesion.

FOCUS OF REVIEW

In this work, we review the medical and surgical management of these tumors with a focus on clinical presentation, diagnostic identification, surgical approach, and associated adjuvant therapies. We will also discuss our current treatment paradigm using endoscopic, open, and combined approaches to craniopharyngiomas. The management of craniopharyngiomas requires a multidisciplinary team of surgeons, endocrinologists, and neuroanesthesiologists as well as neurocritical care specialists to deliver the most comprehensive and safest surgical resection with minimal postoperative morbidity.

Insights into pituitary tumorigenesis: from Sanger sequencing to next-generation sequencing and beyond

Introduction: This review explores insights provided by next-generation sequencing (NGS) of pituitary tumors and the clinical implications.Areas covered: Although syndromic forms account for just 5% of pituitary tumours, past Sanger sequencing studies pragmatically focused on them. These studies identified mutations in MEN1, CDKN1B, PRKAR1A, GNAS and SDHx causing Multiple Endocrine Neoplasia-1 (MEN1), MEN4, Carney Complex-1, McCune Albright Syndrome and 3P association syndromes, respectively. Furthermore, linkage analysis of single-nucleotide polymorphisms identified AIP mutations in 20% with familial isolated pituitary adenomas (FIPA). NGS has enabled further investigation of sporadic tumours. Thus, mutations of USP8 and CABLES1 were identified in corticotrophinomas, BRAF in papillary craniopharyngiomas and CTNNB1 in adamantinomatous craniopharyngiomas. NGS also revealed that pituitary tumours occur in the DICER1 syndrome, due to DICER1 mutations, and CDH23 mutations occur in FIPA. These discoveries revealed novel therapeutic targets and studies are underway of BRAF inhibitors for papillary craniopharyngiomas, and EGFR and USP8 inhibitors for corticotrophinomas.Expert opinion: It has become apparent that single-nucleotide variants and small insertion/deletion DNA mutations cannot explain all pituitary tumorigenesis. Integrated and improved analyses including whole-genome sequencing, copy number, and structural variation analyses, RNA sequencing and epigenomic analyses, with improved genomic technologies, are likely to further define the genomic landscape.

Advances in the management of craniopharyngioma in children and adults

Background Childhood and adult-onset craniopharyngioma is a rare embryogenic tumor of the sellar, suprasellar, and parasellar region. Survival rates are high; however, tumor location and treatment sequalae including endocrine deficits, visual impairment, metabolic complications, cognitive and psychosocial deficits can significantly impair patient's quality of life. There is considerable controversy regarding the optimal management of craniopharyngiomas. Subtotal resection of the tumor followed by targeted irradiation to avoid further hypothalamic damage is currently indicated. Novel insights in the tumor's molecular pathology present the possibility for targeted therapy possibly decreasing the rate and severity of treatment-associated morbidity. Conclusions Craniopharyngioma should be seen as a chronic disease. To achieve optimal outcomes a multidisciplinary team of specialized neurosurgeons, neuro-radiologists, neuro-oncologists, pathologists and endocrinologists should be involved in the diagnosis, planning of the surgery, irradiation and long-term follow-up.

Outcome of Endoscopic Endonasal Surgery in Pediatric Craniopharyngiomas

BACKGROUND

In the last years, few reports have shown the feasibility of the endoscopic endonasal approach (EEA) for craniopharyngiomas in pediatric patients. For these tumors, recent studies have suggested less aggressive surgery, favoring the preservation of the patient's quality of life.

OBJECTIVE

The aim of this study was to assess the outcome of the EEA in a large series with specific attention on the long-term functional sequelae.

MATERIALS

All consecutive pediatric craniopharyngiomas operated on through this approach since 2000 were included in the study. Preoperative and postoperative operative clinical, radiologic, and pathologic features were retrieved from patient records (mean follow-up, 72 ± 67 months).

RESULTS

The series included 25 patients (12 female; mean age, 8.9 ± 4.1 years). Most of the tumors presented with a supradiaphragmatic extension (88%). Removal was radical in 23 patients (92%). Complications consisted of 6 cerebrospinal fluid leaks (24%). One patient (4%) died of postoperative respiratory complications. Most patients (92%) developed panhypopituitarism and visual disturbances normalized or improved in 6 patients (43%). At follow-up, 9 patients (36%) were overweight/obese (6 were already overweight before surgery). The tumor recurrence rate was 19%.

CONCLUSIONS

EEA can be an effective approach for midline craniopharyngiomas in children older than 3 years. It gives a satisfactory exposure of the suprasellar region and an adequate assessment of the brain-tumor interface. Its main limitations are age-related anatomic features of nasal/paranasal sinuses and the risk of cerebrospinal fluid leak.

Salivary ghost cell carcinoma: case report and proposal of a new entity

Various topographically heterogeneous, histologically related groups of basaloid tumours are characterized by ghost cell differentiation with associated CTNNB1 mutations and nuclear β-catenin expression. We describe the unique case of a malignant tumour with ghost cell differentiation in the floor of the mouth, in which clinical, radiological, histological, immunohistological and molecular data altogether strongly indicate classification as a new type of salivary gland carcinoma.

Multiplexed immunofluorescence reveals potential PD-1/PD-L1 pathway vulnerabilities in craniopharyngioma

Background

Craniopharyngiomas are neoplasms of the sellar/parasellar region that are classified into adamantinomatous craniopharyngioma (ACP) and papillary craniopharyngioma (PCP) subtypes. Surgical resection of craniopharyngiomas is challenging, and recurrence is common, frequently leading to profound morbidity. BRAF V600E mutations render PCP susceptible to BRAF/MEK inhibitors, but effective targeted therapies are needed for ACP. We explored the feasibility of targeting the programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) immune checkpoint pathway in ACP and PCP.

Methods

We mapped and quantified PD-L1 and PD-1 expression in ACP and PCP resections using immunohistochemistry, immunofluorescence, and RNA in situ hybridization. We used tissue-based cyclic immunofluorescence to map the spatial distribution of immune cells and characterize cell cycle and signaling pathways in ACP tumor cells which intrinsically express PD-1.

Results

All ACP (15 ± 14% of cells, n = 23, average ± SD) and PCP (35 ± 22% of cells, n = 18) resections expressed PD-L1. In ACP, PD-L1 was predominantly expressed by tumor cells comprising the cyst lining. In PCP, PD-L1 was highly expressed by tumor cells surrounding the stromal fibrovascular cores. ACP also exhibited tumor cell-intrinsic PD-1 expression in whorled epithelial cells with nuclear-localized beta-catenin. These cells exhibited evidence of elevated mammalian target of rapamycin (mTOR) and mitogen-activated protein kinase (MAPK) signaling. Profiling of immune populations in ACP and PCP showed a modest density of CD8+ T cells.

Conclusions

ACP exhibit PD-L1 expression in the tumor cyst lining and intrinsic PD-1 expression in cells proposed to comprise an oncogenic stem-like population. In PCP, proliferative tumor cells express PD-L1 in a continuous band at the stromal-epithelial interface. Targeting PD-L1 and/or PD-1 in both subtypes of craniopharyngioma might therefore be an effective therapeutic strategy.