Craniopharyngioma: historical notes

Patterns of Care in Craniopharyngioma: Clinical Outcomes After Surgery and Radiation Therapy in a Real-World Setting

OBJECTIVE

Craniopharyngioma (CP) is a benign neuroepithelial tumor generally treated with maximal safe resection and radiation therapy (RT) in incompletely resected CP or in recurrent tumors to achieve long-term control. We analyzed the clinical outcomes of patients with CPs treated with a multimodality approach.

PATIENTS AND METHODS

A retrospective clinical audit of histologically proven CPs registered between 2008 and 2019 at a specialized neuro-oncology center in India was performed. Time-to-event outcomes (overall survival [OS] and progression-free survival [PFS]) were analyzed.

RESULTS

One hundred and twenty-two patients with CP were analyzed. The median age of the population was 14 years (interquartile range [IQR], 8-26) with a significant male preponderance. Gross total resection was achieved in only 25% of patients. At a median follow-up of 57.1 months (IQR, 27.8-87.8), 5-year estimates of PFS and OS were 52% (95% confidence interval, 46%-63.4%) and 85.8% (95% confidence interval, 78.6%-93%), respectively. Recurrence or progression was observed in 48 of 122 patients (39.3%) at a median time of 84.4 months (IQR, 24.7-174.8). On multivariate analysis, the absence of residual disease (P = 0.004), near-total resection (P = 0.035), and use of up-front adjuvant RT (P < 0.001) significantly improved the 5-year PFS, whereas the absence of extracavernous extension (P = 0.058) and any use of postoperative RT (P = 0.026) significantly improved the 5-year OS.

CONCLUSIONS

This study represents one of the largest single-institutional series of CPs, showing improved PFS with up-front adjuvant RT in most cases of CP. Deferring adjuvant RT should be considered only in patients with no evidence of residual disease (as shown on dedicated sellar imaging) after primary surgery.

Adamantinomatous craniopharyngioma: evolution in the management

BACKGROUND

In spite of the continuous progresses in pediatric neurosurgery, adamantinomatous craniopharyngioma (AC) remains a challenging tumor due to its proximity to optic pathways, pituitary gland, hypothalamus, and Willis' circle, which can result in significant endocrine, cognitive, and neurological morbidity after treatment with subsequent impact on the patient's quality of life (QoL). The relevance that QoL has today explains the changes in the management of AC observed over the time. The goal of the present article is to provide a historical background, to show the milestones in the changes of the AC treatment, and to analyze the current main options to manage such a challenging tumor.

MATERIAL AND METHODS

The pertinent literature has been reviewed. Moreover, a comparison between the past and recent personal series is reported.

RESULTS

Three main eras have been identified. The first (named Cushing era) was characterized by the need to realize a harmless surgery and to define the best way to approach AC; the second (microscope era) was characterized by a tremendous technical and technological development, with remarkable results in term of safe tumor resection and control but relatively poor QoL outcomes; and the third one (current period) is characterized by an increasing integration between surgery and adjuvant treatments, with relatively minor tumor control but significant improvement of QoL (comparable overall survival). The authors' experience reflects these changes. Two groups of children were compared: 52 cases (mean follow-up: 17.5 years) belong to the historical series (group 1, 1985-2003, aggressive surgical management) and 41 (mean follow-up: 8.5 years) to the current one (Group 2, 2004-2021, integrated management). No significant differences between the two groups were detected about recurrence rate, surgical mortality, and overall survival. However, Group 2 showed significant lower rates of postoperative panhypopituitarism, obesity, and visual deterioration.

CONCLUSIONS

Radical surgery allows for a good AC control with a low rate of recurrence but high risk of permanent morbidity. Despite the greater number of recurrences and surgeries, the more conservative policy, based on a combination of treatments, seems to provide the same tumor control with a better QoL. The advances in trans-nasal and trans-ventricular endoscopy, in proton therapy and in the management of the AC cyst are the main factors that allowed such an improvement.

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.

Craniopharyngiomas

Craniopharyngiomas are rare epithelial tumours situated primarily in the sellar/parasellar region, occurring along the path of the craniopharyngeal duct. Whilst classed as histologically benign tumours, their unpredictable growth pattern and proximity to vital structures including the optic chiasm, hypothalamus, and pituitary gland renders them a considerable threat, with significant associated morbidity and increase in mortality. Occurring both in child and adulthood, their clinical manifestations are broad, commonly with symptoms/signs secondary to hypothalamic-pituitary dysfunction, raised intracranial pressure and visual compromise. They have two distinct histological subtypes (adamantinomatous and papillary), with unique patterns of age distribution, and genetic and molecular make-up. With increasing understanding of their genetic pathogenesis including BRAF V600E mutations in the papillary subtype, and β-catenin mutations in the adamantinomatous, further research provides hope for the discovery of targeted medical therapy that can exploit molecular changes occurring as a result of such alterations. Until then, primary treatment consists of surgery with or without radiotherapy, with intracystic aspiration, chemotherapy or irradiation being alternative options in selected patients. Long term management by an experienced multidisciplinary team is essential, given the breadth of complications, including hypothalamic morbidity, visual compromise, cognitive and neuropsychological sequelae and impairment to quality of life.

Gamma Knife Surgery for Residual or Recurrent Craniopharyngioma After Surgical Resection: A Multi-institutional Retrospective Study in Japan

Objective

The optimal treatment for a craniopharyngioma has been controversial. Complete resection is ideal, but it has been difficult to obtain total resection in many cases because of intimate proximity to critical structures such as the optic pathway, hypothalamus, and pituitary gland. A growing number of studies have demonstrated the utility of radiosurgery in controlling residual or recurrent craniopharyngioma. However, most of them are small series. The aim of this multi-institutional study was to clarify the efficacy and safety of Gamma Knife (Elekta, Stockholm, Sweden) surgery for patients with a craniopharyngioma.

Methods

This was a multi-institutional retrospective study by 16 medical centers of the Japan Leksell Gamma Knife Society. Data on patients with craniopharyngiomas treated with Gamma Knife Surgery (GKS) between 1991 and 2013 were obtained from individual institutional review board-approved databases at each center. A total of 242 patients with craniopharyngioma were included in this study. The mean age of the patients was 41 (range, 3 to 86) years. The median follow-up time was 61.4 months (range, 3 to 180 months). The mean radiosurgery target volume was 3.1 ml (range, 0.03-22.3 ml), and the mean marginal dose was 11.4 Gy (range, 8-20.4 Gy).

Results

Two-hundred twenty patients were alive at the time of the last follow-up visit. The three-, five-, and 10-year overall survival rates after GKS were 95.4%, 92.5%, and 82.0%, respectively. The three-, five-, and 10-year progression-free survival rates after GKS were 73.1%, 62.2%, and 42.6% respectively. The rate of radiation-induced complications was 6.2%.

Conclusion

GKS is effective for controlling the tumor growth of craniopharyngiomas with an acceptable complication rate.

Sequential pathological changes during malignant transformation of a craniopharyngioma: A case report and review of the literature

Background:

Malignant transformation of craniopharyngiomas is quite rare, and the etiology of transformation remains unclear. The prognosis of malignantly transformed craniopharyngiomas is very poor.

Case Description:

A 36-year-old male had five craniotomies, five transsphenoidal surgeries, and two radiation treatments until 31 years of age after diagnosis of craniopharyngioma at 12 years of age. All serial pathological findings indicated adamantinomatous craniopharyngioma including those of a surgery performed for tumor regrowth at 31 years of age. However, when the tumor recurred approximately 5 years later, the pathological findings showed squamous metaplasia. The patient received CyberKnife surgery, but the tumor rapidly regrew within 4 months. The tumor was resected with the cavernous sinus via a dual approach: Transcranial and transsphenoidal surgery with an extracranial-intracranial bypass using the radial artery. Pathologic examination of a surgical specimen showed that it consisted primarily of squamous cells; the lamina propria was collapsed, and the tumor cells had enlarged nuclei and clarification of the nucleolus. The tumor was ultimately diagnosed as malignant transformation of craniopharyngioma. After surgery, he received combination chemotherapy (docetaxel, cisplatin, and fluorouracil). The tumor has been well controlled for more than 12 months.

Conclusion:

Serial pathological changes of the craniopharyngioma and a review of the 20 cases reported in the literature suggest that radiation of the squamous epithelial cell component of the craniopharyngioma led to malignant transformation via squamous metaplasia. We recommend aggressive surgical removal of craniopharyngiomas and avoidance of radiotherapy if possible.

The Wnt signalling cascade and the adherens junction complex in craniopharyngioma tumorigenesis

Craniopharyngiomas are epithelial, sellar tumours with adamantinomatous (aCP) and papillary (pCP) subtypes. The aCP type usually occurs during childhood and pCP in middle-aged adults; aCPs often contain mutations in CTNNB1, encoding β-catenin, a component of the adherens junction and a mediator of Wnt signalling. No such mutational event has been associated with pCPs, where the BRAF gene appears to be more important. In a large series of 95 craniopharyngiomas, we show that the aCP subtype harbours mutations in CTNNB1 in 52 % of cases, while the pCP subtype does not, with agreement between immunohistochemistry and sequencing methods in the majority of cases. When present, the CTNNB1 mutation is found throughout the aCP tumour, while translocation of β-catenin from membrane to cytosol and nucleus is restricted to small cell clusters near the invading tumour front. We observed translocated β-catenin in 100 % of aCPs, occurring not only in cell clusters but also in individual cells scattered throughout the tumour. We characterised the adherens junction involving α-catenin, β-catenin, γ-catenin, p120 and E-cadherin (cytosolic and membranous components). Although suggested to be important in other sellar mass tumourigenesis pathways, there was no disruption of the adherens junction in these tumours, indicating that a loss of junctional integrity is not associated with β-catenin translocation or mutation. We conclude that mutations in CTNNB1 underlie tumourigenesis in the majority of aCPs, which are distinct morphologically and at the molecular level from pCPs.

Gamma Knife surgery for craniopharyngioma: report on a 20-year experience

Object

Although craniopharyngiomas are benign intracranial tumors, their high recurrence rates and intimate associations with surrounding neurovascular structures make gross tumor resection challenging. Stereotactic radiosurgery has been introduced as a valuable adjuvant therapy for recurrent or residual craniopharyngiomas. However, studies with large patient populations documenting long-term survival and progression-free survival rates are rare in the literature. The current study aims to report the long-term radiosurgical results and to define the prognostic factors in a large cohort of patients with a craniopharyngioma.

Methods

A total of 137 consecutive patients who underwent 162 sessions of Gamma Knife surgery (GKS) treatments at the Taipei Veterans General Hospital between 1993 and 2012 were analyzed. The patients' median age was 30.1 years (range 1.5–84.9 years), and the median tumor volume was 5.5 ml (range 0.2–28.4 ml). There were 23 solid (16.8%), 23 cystic (16.8%), and 91 mixed solid and cystic (66.4%) craniopharyngiomas. GKS was indicated for residual or recurrent craniopharyngiomas. The median radiation dose was 12 Gy (range 9.5–16.0 Gy) at a median isodose line of 55% (range 50%–78%).

Results

At a median imaging follow-up of 45.7 months after GKS, the rates of tumor control were 72.7%, 73.9%, and 66.3% for the solid, cystic, and mixed tumors, respectively. The actuarial progression-free survival rates plotted by the Kaplan-Meier method were 70.0% and 43.8% at 5 and 10 years after radiosurgery, respectively. After repeated GKS, the actuarial progression-free survival rates were increased to 77.3% and 61.2% at 5 and 10 years, respectively. The overall survival rates were 91.5% and 83.9% at the 5- and 10-year follow-ups, respectively. Successful GKS treatment can be predicted by tumor volume (p = 0.011). Among the 137 patients who had clinical follow-up, new-onset or worsened pituitary deficiencies were detected in 11 patients (8.0%). Two patients without tumor growth had a worsened visual field, and 1 patient had a new onset of third cranial nerve palsy.

Conclusions

The current study suggests that GKS is a relatively safe modality for the treatment of recurrent or residual craniopharyngiomas, and it is associated with improved tumor control and reduced in-field recurrence rates. Acceptable rates of complications occurred.

Benign lymphoepithelial tumor of the pituitary

Here, we report a case of lymphoepithelial tumor that developed in the sellar and suprasellar regions in a 56-year-old woman. The lesion was composed of abundant but benign squamous cell nests (Erdheim's nests) and heavy lymphoid tissue with well-developed lymphoid follicles. Therefore, it mimicked tonsil or adenoid tissue, but was disorganized. We report this case to define the pathogenesis and proper diagnostic terminology of this unusual sellar and suprasellar lesion, and we assume that its origin is the infundibulum.

Incidence of craniopharyngioma in Denmark (n = 189) and estimated world incidence of craniopharyngioma in children and adults

We studied the incidence of craniopharyngioma in Denmark during the period 1985-2004 and estimated worldwide incidence rates (IR) of craniopharyngioma based on a literature review. Craniopharyngioma patients diagnosed during the period 1985-2004 were identified from the Danish National Patient Registry, the Danish Cancer Registry and regional registries. Medical records were reviewed. Danish population data were obtained from Statistics Denmark. European and World population data were obtained from EU and WHO homepages. Prior studies providing data on craniopharyngioma IRs were identified via PubMed and, if appropriate, were included in a weighted analysis estimating overall and children's IRs of craniopharyngioma. IRs are given as new cases per million per year. We identified 189 patients with new verified (162) or probable craniopharyngioma. The overall WHO World-standardised incidence rate was 1.86 (1.60-2.14) for all ages and 2.14 (1.53-2.92) for children (age <15 years). Peak incidence rates were observed in age groups 5-9 and 40-44 years. Fifteen prior studies (including 1,232 craniopharyngioma cases) were identified. Seven and 11 studies, respectively, were eligible for weighted all-ages and childhood population IR analyses, yielding summary IRs of 1.34 (1.24-1.46) (all ages) and 1.44 (1.33-1.56) (children). We have provided a detailed survey of the incidence of craniopharyngioma in Denmark during a recent 20-year period. Overall IR of craniopharyngioma in Denmark was 1.86 (1.60-2.14) as compared to 2.14 (1.53-2.92) among children. Weighted estimates of craniopharyngioma world IRs were 1.34 (1.24-1.46) in all ages and 1.44 (1.33-1.56) among children.

Outcomes of Gamma Knife surgery for craniopharyngiomas

Gamma Knife surgery (GKS) has emerged as a valuable adjuvant treatment modality for recurrent or residual craniopharyngioma. However, prognostic factors pertaining to progression-free survival (PFS) remain poorly understood. A study was conducted to address this issue. A total of 37 consecutive patients undergoing 39 sessions of GKS procedures targeting the solid portions of the tumors at our institution between 1989 and 2005 were analyzed. Twenty-one male and 16 female patients comprised this study. Median age at GKS was 36 years (range, 4-78). Median tumor volume was 1.6 cm(3) (range, 0.1-18.6), median marginal dose was 14.5 Gy (range, 6-25), and median maximal dose was 30 Gy (range, 15.6-60). Median follow-up was 50 months (range, 8-212). Univariate and multivariate analyses using Cox proportional hazards model were employed to identify the potential prognostic factors including tumor volume, marginal dose, gender, age at GKS, and status of visual field defect (VFD) in terms of in-field PFS. The actuarial 3- and 5-year in-field PFS were 84.8 and 67.0%, respectively. On univariate analysis, absence of VFD at GKS was a favorable prognostic factor (hazard ratio: 0.279; 95% CI, 0.085-0.913, P = 0.035), whereas on multivariate analysis, absence of VFD at GKS, tumor volume ≤1.6 cm(3), and marginal dose >14.5 Gy related to a longer in-field PFS. GKS may offer reasonable control of recurrent or residual craniopharyngiomas. There was a consistent correlation between absence of VFD at the time of GKS and in-field PFS.

Mortality in patients with pituitary disease

Pituitary disease is associated with increased mortality predominantly due to vascular disease. Control of cortisol secretion and GH hypersecretion (and cardiovascular risk factor reduction) is key in the reduction of mortality in patients with Cushing's disease and acromegaly, retrospectively. For patients with acromegaly, the role of IGF-I is less clear-cut. Confounding pituitary hormone deficiencies such as gonadotropins and particularly ACTH deficiency (with higher doses of hydrocortisone replacement) may have a detrimental effect on outcome in patients with pituitary disease. Pituitary radiotherapy is a further factor that has been associated with increased mortality (particularly cerebrovascular). Although standardized mortality ratios in pituitary disease are falling due to improved treatment, mortality for many conditions are still elevated above that of the general population, and therefore further measures are needed. Craniopharyngioma patients have a particularly increased risk of mortality as a result of the tumor itself and treatment to control tumor growth; this is a key area for future research in order to optimize the outcome for these patients.

Molecular pathogenesis of craniopharyngioma: switching from a surgical approach to a biological one

Craniopharyngioma has long been considered a benign tumor because of its pathological aspect. This primordial view of craniopharyngioma fit with the primitive treatment attempts based on blind resection of the tumor each time it recurred. The limits of this management strategy were proven early by the high morbidity related to the resection and recurrence risk despite radical lesion removal. Nowadays, craniopharyngioma must be considered a complex molecular disease, and a detailed explanation of the mechanisms underlying its aggressive biological and clinical behavior, despite some benign pathological features, would be the first step toward defining the best management of craniopharyngioma. Indeed, advances in the knowledge of the molecular mechanisms at the base of craniopharyngioma oncogenesis will lead to comprehension of the critical checkpoints involved in neoplastic transformation. The final research target will be the definition of new biological agents able to reverse the neoplastic process by acting on these critical checkpoints. This biological approach will lead to a refined therapy combining higher efficacy and safety with lower morbidity. In this paper the authors reveal state-of-the-art comprehension of the molecular biology of craniopharyngioma and the consequent therapeutic implications.

Radiation therapy for pediatric craniopharyngioma

Object

The treatment of craniopharyngioma is highly controversial. Continued advances in limited surgery and radiation therapy have maintained excellent local disease control while minimizing treatment-related sequelae. Further analyses of outcomes are necessary to characterize the long-term effects of radiation therapy.

Methods

An extensive literature review was performed for all studies including radiation therapy, with or without surgery, for pediatric craniopharyngioma.

Results

The authors identified 32 papers describing radiation therapy for treatment of pediatric craniopharyngioma, with disease control ranging from 44 to 100%. Modern studies report at least 90% disease control with 5-year follow-up. Fifteen studies reported outcomes, demonstrating that more than two-thirds of patients treated with surgery and radiation therapy have favorable outcomes, and this rate is more than 85% in the modern era.

Conclusions

Conservative surgery and radiation therapy results in long-term disease control in pediatric patients with craniopharyngioma that is comparable to results obtained with radical surgery alone. However, children with craniopharyngioma remain vulnerable to late treatment failures and side effects from radiation therapy, including endocrinopathies, vasculopathies, and secondary tumors, which may be detrimental to the quality of life. Long-term follow-up beyond 5–10 years is necessary to assess tumor control relative to functional outcomes.