Correlation between clinical characteristics and proliferative activity in patients with craniopharyngioma

Predictive Factors for Pediatric Craniopharyngioma Recurrence: An Extensive Narrative Review

Despite being classified as benign tumors, craniopharyngiomas (CPs) are associated with significant morbidity and mortality due to their location, growth pattern, and tendency to recur. Two types can be identified depending on age distribution, morphology, and growth pattern, adamantinomatous and papillary. The adamantinomatous CP is one of the most frequently encountered central nervous system tumors in childhood. Our aim was to review the relevant literature to identify clinical, morphological, and immunohistochemical prognostic factors that have been implicated in childhood-onset CP recurrence. Lack of radical surgical removal of the primary tumor by an experienced neurosurgical team and radiotherapy after a subtotal excision has been proven to significantly increase the recurrence rate of CP. Other risk factors that have been consistently recognized in the literature include younger age at diagnosis (especially <5 years), larger tumor size at presentation, cystic appearance, difficult tumor location, and tight adherence to surrounding structures, as well as the histological presence of whorl-like arrays. In addition, several other risk factors have been studied, albeit with conflicting results, especially in the pediatric population. Identifying risk factors for CP recurrence is of utmost importance for the successful management of these patients in order to ultimately ensure the best prognosis.

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.

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.

Pathological and Prognostic Characterization of Craniopharyngioma Based on the Expression of TrkA, β-Catenin, Cell Cycle Markers, and BRAF V600E Mutation

We collected 61 craniopharyngioma (CP) specimens to investigate the expression of TrkA, β-catenin, BRAF gene mutation, and NTRK1 fusion in CP. There were 37 male and 24 female individuals with a median age of 34 years (range, 4-75 years). Histologically, there were 46 cases of adamantinomatous craniopharyngioma (ACP), 14 cases of papillary craniopharyngioma (PCP), and 1 case with a mixed adamantinomatous and papillary pattern. By immunohistochemistry, we found that moderate/high TrkA expression was detected in 47% (28/60) CP and was significantly higher in adult patients (p = 0.018). Interestingly, TrkA is more expressed in "whorled epithelium" cells in ACP, similar to the localization of abnormal β-catenin. The abnormal expression rate of β-catenin was 70% (43/61), and the medium/high cyclin D1 expression rate was 73% (44/60), both of which were significantly higher in ACP than in PCP. Of the CP, 41% (21/51) had a moderate/strong P16-positive signal; 58% (34/59) showed a high Ki-67 expression, and there was a significant correlation between high Ki-67 L.I. and high tumor recurrence (p = 0.021). NTRK1 fusion was not found in CP by fluorescence in situ hybridization (FISH). By PCR, 26% (15/58) CP showed BRAF V600E gene mutation, which mainly occurred in PCP (100%, 14/14) except one case of mixed CP. Moreover, TrkA expression was negatively correlated with Ki-67 index and positively correlated with P16 expression. There was a significantly negative correlation between BRAF V600E mutation and abnormal β-catenin expression. Our results demonstrate for the first time that TrkA expression might occur in CP, especially in adult CP patients, and suggest that cyclin D1 could be used for ACP histological classification in addition to β-catenin and BRAF V600E mutation, while Ki-67 could be used as a marker to predict CP recurrence.

Heterogeneity of Growth Hormone Receptor Expression in Craniopharyngioma-Implications for Surgical Strategy

BACKGROUND

Recent molecular investigations for craniopharyngiomas have investigated possible predictive biologic markers. Growth hormone receptor (GHR) is thought to be involved in tumor aggressiveness, and high expression of GHR is associated with shorter duration of postoperative stable disease.

CASE DESCRIPTION

A 27-year-old man with a large suprasellar tumor underwent an inexplicable clinical course. Transsphenoidal surgery achieved gross total removal of the tumor. Histologic diagnosis was adamantinomatous craniopharyngioma, and immunohistochemistry revealed very low GHR expression. He was discharged with multiple hormonal supplements except for growth hormone. Recurrence was detected 18 months later, and removal of the second tumor was performed with coagulation of the superior surface of the remaining pituitary gland. Growth hormone supplementation was started in the postoperative period, and he returned to work. However, a further recurrence was detected. Head magnetic resonance imaging showed almost the same pattern of tumor recurrence as preoperative imaging of the second surgery, and simultaneous removal of the tumor and the normal pituitary gland was performed. Reevaluation of histology revealed no morphologic differences between the first and the third surgical specimens, but immunohistochemical staining for GHR showed diffuse high expression in the third specimen. The difference was thought to reflect the heterogeneity of GHR, and appearance of histologic hot spots greatly affected the postoperative prognosis.

CONCLUSIONS

Extensive removal of the possible tumor bed may be necessary for patients requiring growth hormone supplementation even after gross total removal of craniopharyngioma.

Ki67 as a prognostic factor of craniopharyngioma's recurrence in paediatric population

PURPOSE

Craniopharyngioma is one of the most frequent benign tumours of the central nervous system in the paediatric population. Although it is a benign tumour according to the WHO classification, it significantly deteriorates the patient's quality of life. The aim of this study is to assess if proliferation index Ki67 can be a useful marker of the risk of craniopharyngioma's recurrence.

METHODS

Expression of Ki67 was examined in 85 specimens of primary craniopharyngioma and in 11 specimens of the recurring tumour. In all the cases, adamantinomatous type of craniopharyngioma was diagnosed. Values of Ki67 expression were compared between patients with and without recurrence, between patients with progression and relapse and between primary and recurrent tumours.

RESULTS

No statistically significant differences were found between proliferation index Ki67 values in tumours with recurrence and without (median values 2.5% and 3%, respectively, p = 0.69). The median value of proliferation index Ki67 in progression group was 1% and in the relapse group 4%; no statistical significance between those groups was found (p = 0.067). The median value of proliferation index Ki67 in primary tumours was 3% (0-20%) and in recurrent tumours it was 5% (0-14%). Despite the lack of statistical significance (p = 0.61), a tendency towards higher values of Ki67 in recurring tumours in comparison with primary tumours was shown.

CONCLUSIONS

Proliferation index Ki67 is not a reliable prognostic factor of craniopharyngioma's recurrence.

Congenital craniopharyngioma treated by radical surgery: case report and review of the literature

PURPOSE

Craniopharyngiomas are 5-10 % of all pediatric tumors, but are seldomly encountered in the perinatal period. Only seven instances of a truly antenatal diagnosis of a congenital craniopharyngioma that subsequently underwent radical surgery have been reported. We present the case of a patient who received the diagnosis of a suprasellar tumor during the prenatal period and received radical surgery.

METHODS

We report a case of a neonatal craniopharyngioma treated surgically.

RESULTS

The pregnancy progressed uneventfully until a routine ultrasound at 37 weeks of gestation showed a 15 × 15 mm high echoic mass in the center of the fetal head. Neonatal Gd-enhanced T1-weighted MRI at 5 days of life showed a homogenously enhanced mass (16×22×15 mm) in the sellar and suprasellar lesion. As the tumor showed rapid growth at the 3rd month of life, the patient underwent a surgical treatment and the mass was totally removed. Three years later, the physical and mental development of the patient was normal, and Gd-MRI studies showed no tumor recurrence.

CONCLUSION

The present case is the eighth case of a truly antenatal diagnosis of a craniopharyngioma that underwent successful radical surgery. Craniopharyngioma is a benign tumor and thought to be a slow growing tumor in childhood. The results of radical surgery were very poor, and the mortality and morbidity rates were high in the previous reports due to the huge size of tumor at operation. The present case demonstrated the rapid growth in short interval of Gd-MRI. This is the first report of tumor kinetics of congenital craniopharyngioma with previous reports. The calculated tumor doubling time in our case was 37 days.

Prognostic factors of craniopharyngioma with special reference to autocrine/paracrine signaling: underestimated implication of growth hormone receptor

BACKGROUND

Craniopharyngioma is a slow-growing tumor classified as benign, but tight adhesion and significant local infiltration to the vital structures are common. In spite of improvement of modern microsurgery techniques and precise anatomical understanding not few cases of this tumor recur, and long-term tumor control and maintenance of quality of life are sometimes difficult. However, very little is known about the effects of the molecular characters of craniopharyngioma on the prognosis.

METHODS

Ninety eight cases of craniopharyngioma surgically treated at the Department of Neurosurgery, Tohoku University Hospital and Kohnan Hospital from April 1996 to May 2014, 45 males and 53 females aged from 2 to 80 years (mean, 40.84 years) were retrospectively reviewed, and postoperative outcomes and the possible involvement of the autocrine/paracrine mechanism were investigated. The patients were followed up at intervals of 6 months to assess tumor recurrence, and clinical outcomes were correlated with the findings of immunohistochemical examinations used growth hormone receptor (GHR) and downstream hormones. The follow-up period ranged from 3 to 209 months.

RESULTS

Hormone expression was examined in 88 patients, of which 46 specimens (52.3 %) showed high expression of GHR. The GHR high expression group had a significantly shorter duration of postoperative stable disease compared with the low expression group (logrank test, p = 0.007). Simultaneous high expression of growth hormone (GH) and GHR was found in 33 specimens (37.5 %), and the high expression group had a significantly shorter duration of postoperative stable disease compared with the low expression group (logrank test, p = 0.011). No other hormones showed statistically significant differences in outcomes.

CONCLUSIONS

High expression of GHR is associated with shorter duration of postoperative stable disease in patients with craniopharyngioma. If the surgical specimens were craniopharyngiomas with high GHR expression, GH supplementation would be introduced quite prudently.

Osteonectin Expression in Surrounding Stroma of Craniopharyngiomas

Craniopharyngioma is an epithelial tumor of the sellar region with a high survival rate but a high rate of recurrence, especially in children. Hypothalamic involvement, tumor recurrence, and multiple treatments result in clinical deterioration and impaired quality of life. Using immunohistochemistry, we investigated the expression pattern of osteonectin, a marker of tumor invasion and aggressive behavior, in 43 cases of craniopharyngioma. We observed a positive correlation of osteonectin expression in connective-type stromal tissue surrounding the epithelial tumor cells of craniopharyngioma with the extent of central nervous system infiltration and recurrence rate ( P < .001). Given the previous success of chemotherapeutic agents that target the tumor microenvironment, our findings on osteonectin expression in stroma of craniopharyngiomas might, hopefully, be a guide to find newer prognostic markers capable of estimating the risk of progression or recurrence. They may also aid in the development of therapeutics that target tumor microenvironment to improve patient outcome.

Molecular oncogenesis of craniopharyngioma: current and future strategies for the development of targeted therapies

Craniopharyngiomas are benign intracranial tumors that arise in the suprasellar and intrasellar region in children and adults. They are associated with calcification on neuroimaging, endocrinopathies, vision problems, and recurrence following subtotal resection. Molecular studies into their genetic basis have been limited, and therefore targeted medical therapies for this tumor have eluded physicians. With the discovery of aberrant Wnt/β-catenin pathway signaling in the pathogenesis of the most common subtype of craniopharyngioma (adamantinomatous), the identification of candidate genes and proteins implicated in this cascade provide attractive targets for future therapies. The recent development of a genetically engineered animal model of this tumor may also serve as a platform for evaluating potential therapies prior to clinical trials in humans. Advances in understanding the molecular pathogenesis of tumor recurrence have also been made, providing clues to develop adjuvant and neoadjuvant therapies to couple with tumor resection for optimal response rates. Finally, advances in genomic technologies and next-generation sequencing will underlie the translation of these genetic and molecular studies from the bench to clinical practice. In this review, the authors present an analysis of the molecular oncogenesis of craniopharyngioma and current directions in the development of novel therapies for these morbid, yet poorly understood brain tumors.

Predictive factors for craniopharyngioma recurrence: a systematic review and illustrative case report of a rapid recurrence

BACKGROUND

Recurrence of craniopharyngiomas (CPs) represents a frequent and unpredictable incident. Rapid tumor recurrence within a few months after surgery has been rarely reported. Nondefinitive predictive factors for rapid CP recurrence have been identified to date. We have systematically analyzed the tumor factors that presumably influence in CP recurrence.

METHODS

We present the histologic and immunohistochemical analysis of an infundibulo-tuberal CP that was operated twice within a 3-month interval due to rapid recurrence. We investigated the differential characteristics of the subgroup of CPs that recurred in large surgical series published in the literature, along with cases reporting rapid tumor recurrence after surgery.

RESULTS

Specimens of our patient showed an adamantinomatous CP with whorl-like arrays and thick peritumoral gliosis. Ki-67 labeling index in primary and recurrent samples was 20% and 15%, respectively. p53 labeling index was 18% and 15%, respectively. The thorough analysis of literature showed that presence of tumor remnants and missing radiotherapy treatment after subtotal removal are strong predictors of tumor recurrence. Third ventricle involvement, large tumor size, tight adherence to surrounding structures, and presence of whorl-like arrays might also foster recurrence. High Ki-67 levels, p53 expression, and an intense reactive gliosis might point to rapid tumor growth.

CONCLUSIONS

Reliable tumor markers that predict CP recurrence are still lacking. The CP features presumably related to a higher risk of its recurrence are thought to be a larger tumor size, a tight adherence to the hypothalamus, the presence of whorl-like arrays, and high Ki-67 and p53 levels.

Expression of matrix metalloproteinase-9, type IV collagen and vascular endothelial growth factor in adamantinous craniopharyngioma

To explore the expression of matrix metalloproteinase 9 (MMP-9), type IV collagen (Col IV) and vascular endothelial growth factor (VEGF) in adamantinomatous craniopharyngioma (ACP) and analyze the correlation between the level of these markers and adamantimous craniopharyngiomas recurrence. Expressions of MMP-9, Col IV and VEGF were tested by immunohistochemistry (IHC) in 40 cases of ACP, including 24 cases of primary group and 16 cases of recurred group. The expression level of MMP-9 and VEGF in recurred group were significantly higher than primary group (93.7% vs. 41.7%, P < 0.05, 87.5% vs. 45.8%, P < 0.05, respectively). The expression of Col IV in the recurred group was significant different from the primary group (Z = -2.619, P < 0.05). MMP-9, Col IV and VEGF may be the potential specific bio-marker related to the recurrence of ACP.

Neurosurgical treatment of craniopharyngioma in adults and children: early and long-term results in a large case series

OBJECT

Craniopharyngioma accounts for 2%-5% of all primary intracranial neoplasms. The optimal management of craniopharyngioma remains controversial. The authors evaluated the early results of surgery and the longterm risk of tumor recurrence in a large series of patients undergoing resection of craniopharyngiomas.

METHODS

Between 1990 and 2008, 112 consecutive patients (57 male and 55 female patients with a mean [± SEM] age of 33.3 ± 1.8 years) underwent resection of craniopharyngiomas at the authors' hospital. Recurrence or growth of residual tumor tissue during follow-up was assessed using MR imaging.

RESULTS

There were 3 perioperative deaths (2.7%). Severe adverse events were more frequent in patients who underwent operations via the transcranial route (37%) than the transsphenoidal approach (5.6%; p < 0.001). Magnetic resonance imaging showed radical resection of the tumor in 78 (71.6%) of the remaining 109 patients. Previous surgery and maximum tumor diameter were associated with persistence of disease after surgery. Craniopharyngioma recurred in 26 (24.5%) of 106 patients. Presence of residual tumor on the first postoperative MR imaging, male sex, and no postoperative radiation therapy were associated with a risk of tumor recurrence. Quality-of-life data were assessed in the 91 patients who attended the authors' institution for follow-up visits. Among them, 8.8% patients were partially or completely dependent on others for daily living activities before surgery. This percentage increased to 14.3% at the last follow-up visit. The 5- and 10-year overall survival rates were 94.4% (95% CI 90.0%-98.8%) and 90.3% (95% CI 83.4%-97.3%), respectively.

CONCLUSIONS

Complete surgical removal of craniopharyngioma can be achieved with reasonable safety in more than 70% of patients. Recurrence of craniopharyngioma may occur even after apparent radical excision. Prompt management of residual or recurring disease by radiotherapy, repeat surgery, or a combination of both is usually successful in controlling further tumor growth.

Novel immunohistochemical markers in the diagnosis of nonglial tumors of nervous system

Immunohistochemistry (IHC) has become an important adjunct tool in diagnostic neuro-oncology practice enabling immunophenotypic characterization of tumor cells. There have been several recent publications regarding new IHC markers that are useful for diagnosis of brain tumors. To introduce the latest advances in IHC in this field, we review the features of novel IHC marker antibodies applicable to selected nonglial tumors in the nervous system, based on recently published reports and our own experiences. We discuss (1) aquaporin-1 and alpha-inhibin for hemangioblastoma, (2) beta-catenin for craniopharyngioma, (3) brachyury for chordoma, and (4) INI-1 for hereditary schwannomas. All the markers presented here are used primarily for supporting or confirming the histologic diagnosis, with the exception of (4), which may be of help in identification of inherited forms in schwannomas. As with other surgical pathology practices, the judicious use of a panel of IHC antibodies selected on the basis of the histologic findings is important for an accurate diagnosis of brain tumors. Of note is that IHC results should be always interpreted in the histopathologic context.

The cell-cycle kinetics of craniopharyngioma and its clinical significance

Craniopharyngioma (CP) is a pathologically benign tumor with high incidence of recurrence and poor prognosis. DNA ploidy, S-phase fraction (SPF), and G2 phase/mitosis phase + S phase (G2/M + S) measured by flow cytometry (FCM) have been shown to correlate with cell cycle characteristics and clinical prognosis of other tumors. By use of FCM and terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) peroxidase, we compared DNA content, SPF, G2/M + S, necrosis and apoptosis in non-recurrent and recurrent tumor cells of CP from 63 cases including 32 adamantine epitheliomas (AEs) and 31 squamous papillary tumors (SPTs), and the ultrastructure of the CP cell was observed by transmission electron microscopy. Although no obvious differences between DNA content and necrosis and apoptosis rate were observed in subgroups of CPs, SPF and G2/M + S for recurrent tumors were statistically higher than those for recurrence-free tumors, and the recurrence rate of AE tumors is higher than that of SPT. Therefore, CP cells are diploid, and SPF and G2/M + S are related to recurrence of CP.

Morphological and Ultrastructural Findings of Prognostic Impact in Craniopharyngiomas

Craniopharyngioma is a slow-growing epithelial tumor with an unpredictable tendency to recur. To verify the reliability in predicting the clinical outcome, some morphological and immunohistochemical findings were analyzed in 37 primitive tumors and in 6 recurrences (one recurred twice). All the tumors were surgically excised and all recurrences exhibited an adamantinomatous pattern; mitotic rate was low (< 5 x 10 HPF) in both recurrent and in nonrecurrent tumors. Primary tumors showed a mean positivity of 1.7% (range 0.3-2%) to PCNA vs. 4.1% (range 0.3-8%) in recurrences. The MIB-1 Labelling Index was: 22.12% in primary tumors, 27.5% in recurrences, 31.3% in adult nonrecurrent tumors, and 4.1% in the pediatric tumor. CD34 labeling vessels/field was 9.3 in primary tumors and 9.91 in the recurrences; VEGF expression was higher in recurrences than in primary tumors (40 vs. 25%). Ultrastructural analysis showed fenestrated endothelium with hydropic changes in VEGF-positive vessels. Lack of clear correlations between morphological or immuno-staining patterns and behavior suggests that these features have no prognostic value in adult as well as in pediatric craniopharyngiomas. In this study, the only results that may be related to the aggressiveness of tumor is the major vascularization in the recurrent tumors in which the vessels show also ultrastructural changes.

Craniopharyngiomas

Craniopharyngiomas are epithelial tumors arising along the path of the craniopharyngeal duct and presenting with a variety of manifestations. Their optimal management remains a subject of debate. Currently, surgical excision followed by external beam irradiation is the main treatment option. Craniopharyngiomas are associated with significant long-term morbidity and mortality rates.

Expression of human MCM6 and DNA Topo II alpha in craniopharyngiomas and its correlation with recurrence of the tumor

Craniopharyngioma often recurs after resection resulting in poor outcome for the affected patients. The reliable criteria for predicting the tumor behavior are still lacking. It has been suggested that proliferative potential of the tumor cells is necessary for recurrence. Present study evaluated the cell multiplication activity, which is possibly related to relapse in 32 patients with adamantine epithelioma (AE) and 31 patients with squamous papillary tumor (SP). For this tissue specimens from their primary and recurring tumors were collected and immunohistochemical analysis of the expression of minichromosome maintenance protein 6 (MCM6) and DNA topoisomerase II alphalpha (DNA Topo II alpha) in the tumor sections was performed by quantitative microscopy. It was found that the MCM6 label index (LI) was significantly higher in AE than that of SP, and in the primary tumors of both subtypes the LIs of tumors with recurrence were higher than those without recurrence. There was a strong linear positive correlation between MCM6 LI and DNA Topo II alpha LI (r = 0.713; p = 0.000) in the craniopharyngiomas studied. The median MCM6 LI of the total 20 recurrent craniopharyngiomas (31.49%) was not significantly different from that of their primary tumors (29.65%). The long term risk of tumor recurrence is higher in AE than SP and it is associated with MCM6 and DNA Topo II alpha expression.

Clinico-pathological and immunohistochemical characteristics associated to recurrence/regrowth of craniopharyngiomas

BACKGROUND

Craniopharyngioma is a rare, benign epithelial brain tumor of the suprasellar region with a high rate of recurrence. Clinical and histopathological features that might be predictors of recurrence/regrowth have not been clearly delineated.

METHODS

We compared recurrence/regrowth of the tumors with the clinico-pathological characteristics, vascular density, cell proliferation index, and immunohistochemical profile (cytokeratins, epithelial membrane antigen [EMA], carcinoembrionary antigen [CEA], and laminin) of 47 patients with craniopharyngioma followed for more than 5 years.

RESULTS

Tumors were adamantinomatous in 42 cases (89%) and papillary squamous in 5 cases (11%). Immunoreactivity for cytokeratin 8/18/19 was positive in 64%; cytokeratin 5 in 42%; laminin 8 in 62%; and CEA in 21%. The cell proliferation index and vascular density were greater in adamantinomatous than in papillary tumors (22+/-6 versus 17+/-3, p=0.05; and 21+/-3 versus 17+/-3, p=0.037, respectively); they were neither related to recurrence nor to regrowth. No significant differences were found between adamantinomatous and papillary tumors regarding the presence of cytokeratin, laminin, CEA or glial fibrillary acidic protein (GFAP). Recurrence rate at 5 years was 59%. No relation was found between recurrence and adjuvant radiotherapy (AR). Residual tumor after surgery, whorl-like arrays (p=0.04) and immunoreactivity for p53 (p=0.022) were significantly related to recurrence/regrowth.

CONCLUSIONS

Residual tumor after surgery, immunoreactivity to p53 and presence of whorl-like arrays are associated to recurrence/regrowth of craniopharyngioma.

Microvascular density and vascular endothelial growth factor have little correlation with prognosis of craniopharyngioma

BACKGROUND

Craniopharyngioma is histologically a benign epithelial tumor located in the supersellar cistern that often presents aggressive growth and repeated recurrence. The authors hypothesized that craniopharyngioma recurrence and invasive growth are angiogenesis dependent and evaluated the significance of vascularization in the prognosis of craniopharyngioma by a prospective cohort study.

METHODS

The cohorts consisted of 32 patients with AE and 31 patients with SP tumor. The primary and recurrence removal specimens of the cohort patients were gathered. Microvascular density and VEGF protein in the recurrence group and recurrence-free group were detected by the immunohistochemistry avidin-biotin-peroxidase method and analyzed quantitatively through computer-assisted microscopy to evaluate the correlation of MVD and VEGF with prognosis of craniopharyngiomas.

RESULTS

The average follow-up phase was 63.34 months; 14 of 32 patients with AE and 6 of 31 patients with SP had recurrence and underwent operation again. Although MVD and VEGF have significant difference between AE and SP (P=.000, P=.018, respectively), MVD and VEGF have no statistical difference between the recurrence group and recurrence-free group (P>.05).

CONCLUSIONS

Microvascular density and VEGF in craniopharyngioma tissue have no correlation with prognosis of the tumor, which may be explained by the minimal blood circulation in the craniopharyngioma. Adamantine epithelioma showed more tendency to recur than SP.

Craniopharyngiomas

Craniopharyngiomas are rare, mainly sellar/parasellar, epithelial tumors diagnosed during childhood or adult life. Histologically, two primary subtypes have been recognized (adamantinomatous and papillary) with an as yet, unclarified pathogenesis. They may present with a variety of manifestations (neurological, visual, and hypothalamo-pituitary). Despite their benign histological appearance, they often show an unpredictable growth pattern, which, combined with the lack of randomized studies, poses significant difficulties in the establishment of an optimal therapeutic protocol. This should focus on the prevention of recurrence(s), improvement of survival, reduction of the significant disease and treatment-related morbidity (endocrine, visual, hypothalamic, neurobehavioral, and cognitive), and preservation of the quality of life. Currently, surgical excision followed by external beam irradiation, in cases of residual tumor, is the main treatment option. Intracystic irradiation or bleomycin, stereotactic radiosurgery, or radiotherapy and systemic chemotherapy are alternative approaches; their place in the management plan remains to be assessed in adequately powered long-term trials. Apart from the type of treatment, the identification of clinical and imaging parameters that will predict patients with a better prognosis is difficult. The central registration of patients with these challenging tumors may provide correlates between treatments and outcomes and establish prognostic factors at the pathological or molecular level that may further guide us in the future.

Long-term results of the surgical treatment of craniopharyngioma: the experience at the Policlinico Gemelli, Catholic University, Rome

BACKGROUND

Craniopharyngioma (CP) is the most common intracranial non-glial tumour observed in pediatric age. Although histologically benign and amenable to surgical treatment, its location and relation with vital nervous and vascular structures makes the feasibility of a radical resection difficult even in the microneurosurgery era. Beside the difficulties experienced when performing tumour resection, post-operative complications, such as endocrinological imbalance, represent another point that makes CP total excision a challenge. In order to avoid such complications, some authors have suggested to renounce to radical resection and to rely on post-operative radiation therapy to minimise the risk of residual tumour progression.

METHODS

We report our experience with 52 children and adolescents operated on for CP at the Department of Pediatrics, Section of Pediatric Neurosurgery, Catholic University Medical School, Rome, between January 1985 and December 2002. The study included 14 children <5 years old (five less than 2 years of age), 25 between 6 and 10 years old, and 13 more than 10 years old. The most common presenting signs were related to endocrinological imbalance (35 cases), increased intracranial pressure (32 cases), and to a lesser extent, visual compromise (17 cases). Concerning location, CP was intrasellar in three cases; sellar/suprasellar with prominent prechiasmatic growth in 24 cases; retrochiasmatic/3rd ventricular in 14 cases, and giant (with an extension into the middle and/or posterior cranial fossae) in 11 cases. The tumour was managed by means of a single surgical approach in 47 cases and with a two-stage operation in the remaining five cases. In 11 cases of intrasellar or intra/suprasellar midline location, the first surgical approach was done through the transsphenoidal route (which represented the first step of a staged operation in five instances); in the remaining 41 patients, craniotomy was the first surgical procedure. Radical tumour resection was achieved in 40 cases, subtotal (only small tumour remnants adherent to the carotid arteries, 3rd ventricle floor or visual pathways) in nine, and only partial in the remaining three cases

RESULTS

Histology demonstrated the adamantinous variant in all cases. Two surgical deaths were recorded in this series (both following a transsphenoidal approach): one secondary to uncontrollable intra-operative bleeding from the carotid artery, and the other to fulminating bacterial meningoencephalitis. Morbidity included endocrinological disturbances, namely hypopituitarism and diabetes insipidus, in more than 80% of cases, worsening of pre-operative visual deficit in six cases, and transitory neurological deficits in five cases. One late death was recorded 2 years after surgery, secondary to electrolytic imbalance although favoured by a major head trauma with subacute subdural haematoma. Nine recurrences occurred 1-8 years after surgery (three true recurrences, and six re-growths of incompletely resected tumours) that required re-operation. Twelve patients underwent radiotherapy, six after an initially incomplete tumour resection and six following relapse. One patient presented with a malignant thalamic glioma 8 years after radiotherapy. At long-term follow-up, all survivors showed good clinical condition, even though approximately 60% relied on hormone replacement, and some patients presented obesity. Diabetes insipidus has subsided in about 80% of the cases; visual deficits improved or remained stable, whereas post-operative neurological deficits subsided in all but one patient.

CONCLUSION

In our experience, radical resection of CP represented the first and almost unique treatment modality. Although not insignificant, post-operative mortality and morbidity do not seem to represent a major contraindication in attempting a radical tumour resection whenever possible. On the other hand, extensive hypothalamic involvement should suggest a less aggressive attitude.

Angiogenesis and the growth potential of craniopharyngiomas

The present study was performed to evaluate the role of neovascularization on the behavior of craniopharyngiomas as well as the contribution of endothelial cell proliferation and migration in the remodeling and expansion of the vascular network associated with angiogenesis. Fourteen primary tumors were studied, all of the adamantinomatous type. CD34 immunostaining, an endothelial cell marker, localized vessels within the connective tissue stroma. MIB-1 immunopositivity was apparent in the nuclei of neoplastic cells, few endothelial cells, and stromal elements. MIB-1 counts were higher in epithelial than connective tissue cells. A positive correlation was found between the number of MIB-1 immunopositive cells and microvessel density (MVD). Immunohistochemistry demonstrated that integrin alphavbeta3 expression was restricted to tumor vasculature; the tumor cells were immunonegative. Only 2.5% of vessels detected with CD34 were immunopositive for integrin alphavbeta3. At present, no therapeutic implications can be drawn from our observations. More studies are needed to assess whether integrin alphavbeta3 antagonists or drugs that arrest the cell cycle of endothelial cells can inhibit angiogenesis in craniopharyngiomas.

Prognosis-related histomorphological and immunohistochemical markers in central nervous system tumors of childhood and adolescence

Brain tumors account for approximately 20% of all childhood cancers, and are the leading cause of cancer morbidity and mortality among children. Although numerous demographic, clinical and therapeutic parameters have been identified over the past few years that have significant prognostic bearing for some pediatric brain tumors, predicting the clinical course and outcome among children with central nervous system tumors is still difficult. A survey of publications on prognosis-related histopathological and immunohistochemical features among pediatric brain tumors revealed 172 series, of which 91 presented statistically significant outcome-associated parameters as defined by a P value of less than 0.05. Most investigations revealing significant prognosis-related markers were performed on medulloblastomas (30 publications), ependymomas (25) and astrocytic tumors (18). In total, 16 cohorts consisted of more than 100 cases (5 on ependymomas, 3 each on medulloblastomas and astrocytic tumors). On the other hand, there were also 13 series with fewer than 20 cases (5 on medulloblastomas). Potentially prognostic histopathological markers vary among different entities and consist of assessment of necroses, mitoses, differentiation, vascular proliferation, and growth pattern, whereas immunohistochemical features include proliferation markers (Ki-67, MIB-1), expression of oncogenes/tumor suppressor genes and their proteins (TP53, c-erbB2), growth factor and hormonal receptors (VEGF, EGFR, HER2, HER4, ErbB-2), cell cycle genes (p27, p14ARF) and cell adhesion molecules, as well as factors potentially related to therapeutic resistance (DNA topoisomerase IIalpha, metallothionein, P-glycoprotein, tenascin). This review discusses the prognostic potential of histopathological and immunohistochemical markers that can be investigated by the practicing neuropathologist as part of the routine diagnostic workload, and scrutinizes their benefit for predicting therapy response and patient outcome among children with brain tumors.