Preoperative Assessment of Craniopharyngioma Adherence: Magnetic Resonance Imaging Findings Correlated with the Severity of Tumor Attachment to the Hypothalamus

Topography and Radiological Variables as Ancillary Parameters for Evaluating Tissue Adherence, Hypothalamic-Pituitary Dysfunction, and Recurrence in Craniopharyngioma: An Integrated Multidisciplinary Overview

Craniopharyngiomas continue to present a challenge in clinical practice due to their heterogeneity and unpredictable adherence to vital neurovascular structures, particularly the hypothalamus. This results in different degrees of hypothalamus-pituitary axis dysfunction and a lack of uniform consensus and treatment guidelines regarding optimal management. MRI and CT are complementary techniques in the preoperative diagnostic phase, enabling the precise definition of craniopharyngioma size, shape, and consistency, as well as guiding classification into histopathological subtypes and topographical categories. Meanwhile, MRI plays a crucial role in the immediate postoperative period and follow-up stages by identifying treatment-related changes and residual tumors. This pictorial essay aims to provide an overview of the role of imaging in identifying variables indicative of the adherence degree to the hypothalamus, hypothalamic-pituitary dysfunction, the extent of surgical excision, and prognosis. For a more comprehensive assessment, we choose to distinguish the following two scenarios: (1) the initial diagnosis phase, where we primarily discuss the role of radiological variables predictive of adhesions to the surrounding neurovascular structures and axis dysfunction which may influence the choice of surgical resection; (2) the early post-treatment follow-up phase, where we discuss the interpretation of treatment-related changes that impact outcomes.

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.

Neuroimaging of pediatric tumors of the sellar region-A review in light of the 2021 WHO classification of tumors of the central nervous system

Sellar/suprasellar tumors comprise about 10% of all pediatric Central Nervous System (CNS) tumors and include a wide variety of entities, with different cellular origins and distinctive histological and radiological findings, demanding customized neuroimaging protocols for appropriate diagnosis and management. The 5th edition of the World Health Organization (WHO) classification of CNS tumors unprecedently incorporated both histologic and molecular alterations into a common diagnostic framework, with a great impact in tumor classification and grading. Based on the current understanding of the clinical, molecular, and morphological features of CNS neoplasms, there have been additions of new tumor types and modifications of existing ones in the latest WHO tumor classification. In the specific case of sellar/suprasellar tumors, changes include for example separation of adamantinomatous and papillary craniopharyngiomas, now classified as distinct tumor types. Nevertheless, although the current molecular landscape is the fundamental driving force to the new WHO CNS tumor classification, the imaging profile of sellar/suprasellar tumors remains largely unexplored, particularly in the pediatric population. In this review, we aim to provide an essential pathological update to better understand the way sellar/suprasellar tumors are currently classified, with a focus on the pediatric population. Furthermore, we intend to present the neuroimaging features that may assist in the differential diagnosis, surgical planning, adjuvant/neoadjuvant therapy, and follow-up of this group of tumors in children.

Characteristics and factors influencing hypothalamic pituitary dysfunction in patients with craniopharyngioma

Background

Craniopharyngioma is a benign tumor originating from the sellar region. Damages in this area caused by the tumor itself, surgery, or radiotherapy may result in severe hypothalamic-pituitary dysfunction (HPD) and eventually lead to a significant impairment in the long-term quality of life of patients. This study aimed to investigate the characteristics of HPD in patients with adamantinomatous craniopharyngioma (ACP) or papillary craniopharyngioma (PCP) and to identify the factors affecting HPD after surgery.

Methods

In this single-center retrospective study, a total of 742 patients with craniopharyngioma were included. The neuroendocrine function of these patients before and after surgery was investigated. The differences in hypothalamic-pituitary function between the ACP and PCP groups were compared. The factors influencing the aggravation of HPD after surgery were identified.

Results

The median follow-up after surgery was 15 months. Before surgery, the proportion of patients with diabetes insipidus (DI) and hyperprolactinemia in the PCP group was significantly higher than that in the ACP group (P<0.01), and the proportion of patients with adrenocortical hypofunction in the PCP group was significantly lower than that in the ACP group (P=0.03). Most cases of ACP originated in the sellar region, while most cases of PCP originated in the suprasellar region (P<0.01). More patients experienced adenohypophyseal hypofunction, DI, and hypothalamic obesity at postoperative follow-up than at onset in both the ACP and PCP groups (both P<0.01), with a higher increase observed in the ACP group (P<0.01). Older age at CP onset, tumor recurrence or progression, and ACP type were risk factors for postoperative aggravation of HPD in CP patients.

Conclusion

Surgical treatment significantly aggravated HPD in both the ACP and PCP groups, but the specific characteristics and risk factors leading to aggravation were different between the two groups.

Exploring the pathological relationships between adamantinomatous craniopharyngioma and contiguous structures with tumor origin

PURPOSE

Identifying relationships between craniopharyngiomas (CPs) and contiguous structures, and tumor origin are crucial for treatments. This study attempted to explore the relationships and tumor origin.

METHODS

CPs that underwent endoscopic surgeries were enrolled. The interfacial specimens of CPs attaching the hypothalamus, pituitary stalk (PS), pituitary grand (PG), optic chiasma (OC) and brain tissue (BT) were pathologically examined. Boundaries between CPs and these structures were observed during operations. Expression of β-catenin and stem cell markers were analyzed to explore the tumor origin. Outcomes of patients were assessed.

RESULTS

A total of 34 CPs were categorized into two groups based on the locations of finger-like protrusions (FP). Group A comprised 18 CPs with FP only present in the specimens attaching to hypothalamus. The surface of these CPs was fused with hypothalamus under endoscopic videos. However, the specimens attaching to the PS, PG, OC, and BT showed no FP. Clear boundaries was observed between these CPs and these structures. Group B comprised 16 CPs with FP only present in the specimens attaching to PS. The tumor surface was fused with PS. Specimens attaching to the hypothalamus, PG, OC and BT showed no FP. Clear boundary was observed among these CPs with these structures. These results implied CPs only invaded a certain part of hypothalamic-pituitary axis. β-catenin and stem cells markers mainly distributed in the FP tissues of both groups. Patients in group B achieved better outcomes than group A.

CONCLUSIONS

CPs only invade the hypothalamic-pituitary axis with FP and the FP would be the tumor origin.

Role of endoscopic endonasal approach for craniopharyngiomas extending into the third ventricle in adults

•EAA is an innovative, promising, safe and effective approach for 3VCPs.•Key of success is surgeon learning curve in endoscopy and patients selection.•With correct indications, EEA gives GTR and morbidity rate similar to other routes.•Clinical, tumoral and anatomical features should be considered for EEA selection.

Basal Recess in Third Ventricle Tumors: A Pathological Feature Defining a Clinical-Topographical Subpopulation of Papillary Craniopharyngiomas

This study investigates the presence of a hollow recess at the midline undersurface of tumors primarily localized within the third ventricle (3V). This structure was originally identified by magnetic resonance imaging (MRI) of 6 3V craniopharyngiomas (CPs) from our series and was then methodically scrutinized in autopsy studies (n = 1091) and MRI scans (n = 5558) of CPs and in 1251 3V tumors reported in the medical literature from 1839 to 2021. A recess at the tumor base was identified in 110 CPs, 95 with a verified papillary histology (papillary craniopharyngioma [PCP]) and 15 with typical gross appearance of PCP. Topographically, 90 tumors were strictly within the 3V (82%); 20 developed at the infundibulo-tuberal region of the 3V floor (18%). Morphologically, 2 main types of recess were identified: (i) a long, narrow recess with either a duct-like or a tubular shape that reached the central region of the CP (n = 47, 42.5%); and (ii) a short recess extending only a few millimeters into the lesion, either with a duct-like or a shallow cleft-like morphology (n = 63, 57.5%). Thus, the presence of a basal recess represents a pathological hallmark of a subpopulation of 3V PCPs. The presumed nature and diagnostic significance of this novel finding is comprehensively addressed.

Papillary Craniopharyngioma: A Type of Tumor Primarily Impairing the Hypothalamus - A Comprehensive Anatomo-Clinical Characterization of 350 Well-Described Cases

OBJECTIVE

Papillary craniopharyngiomas (PCPs) represent a rare histological type of craniopharyngiomas (CPs) usually involving the hypothalamus. This study systematically analyzes the clinical-anatomical correlation between tumor topography and symptoms related to hypothalamic dysfunction in the largest series of PCPs ever gathered.

METHODS

From 5,346 CP reports published from 1856 to 2021, we selected 350 well-described cases of the squamous-papillary type. Clinical presentation, tumor topography, severity of hypothalamic adhesion, patient outcome, and tumor recurrence were thoroughly analyzed.

RESULTS

PCPs predominantly occur in adult (96.3%), male (61.7%) patients presenting with headache (63.4%), visual alterations (56.2%), and psychiatric disturbances (50.4%). Most PCPs are solid (50%), round (72%) lesions that occupy the third ventricle (3V, 94.8%) and show low-risk severity adhesions to the hypothalamus (66.8%). Two major topographical categories can be found: strictly 3V (57.5%), growing above an intact 3V floor, and not-strictly or infundibulo-tuberal (32.9%), expanding at the infundibulum and/or tuber cinereum. The hypothalamic syndrome predominated among strictly 3V PCPs (p < 0.001). Psychiatric symptoms (p < 0.001) and high-risk hypothalamic attachments (p = 0.031) related to unfavorable postoperative outcomes among patients treated from 2006 onwards. The not-strictly 3V topography was identified as the major predictor of high-risk hypothalamic attachments (71.2% correctly predicted), which, along with incomplete tumor removal (p = 0.018), underlies the higher tumor recurrence of this topography (p = 0.001).

CONCLUSIONS

This systematic review evidences that PCP topography is a major determinant of hypothalamic-related symptoms, type of hypothalamic attachments, and tumor recurrence rate. Accurate preoperative definition of PCP-hypothalamus relationships is essential for the judicious, safe management of these complex lesions.

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.

Strictly third ventricle craniopharyngiomas: pathological verification, anatomo-clinical characterization and surgical results from a comprehensive overview of 245 cases

The strictly third ventricle craniopharyngioma topography (strictly 3V CP) defines the subgroup of lesions developed above an anatomically intact third ventricle floor (3VF). The true existence of this exceedingly rare topographical category is highly controversial owing to the presumed embryological CP origin from Rathke's pouch, a structure developmentally situated outside the neural tube. This study thoroughly analyzes the largest series of strictly 3V CPs ever collected. From 5346 CP reports published between 1887 and 2021, we selected 245 cases with reliable pathological, surgical, and/or neuroradiological verification of an intact 3VF beneath the tumor. This specific topography occurs predominantly in adult (92.6%), male (64.4%) patients presenting with headache (69.2%), and psychiatric disturbances (59.2%). Neuroradiological features defining strictly 3V CPs are a tumor-free chiasmatic cistern (95.9%), an entirely visible pituitary stalk (86.4%), and the hypothalamus positioned around the tumor's lower pole (92.6%). Most are squamous papillary (82%), showing low-risk severity adhesions to the hypothalamus (74.2%). The adamantinomatous variant, however, associates a higher risk of severe hypothalamic adhesion (p < .001). High-risk attachments are also associated with psychiatric symptoms (p = .013), which represented the major predictor for unfavorable prognoses (83.3% correctly predicted) among cases operated from 2006 onwards. CP recurrence is associated with infundibulo-tuberal symptoms (p = .036) and incomplete surgical removal (p = .02). The exclusive demographic, clinico-pathological and neuroradiological characteristics of strictly 3V CPs make them a separate, unique topographical category. Accurately distinguishing strictly 3V CPs preoperatively from those tumors replacing the infundibulum and/or tuber cinereum (infundibulo-tuberal or not strictly 3V CPs) is critical for proper, judicious surgical planning.

An endoscopic endonasal approach to craniopharyngioma via the infrachiasmatic corridor: a single center experience of 84 patients

OBJECT

The infrachiasmatic corridor is the most important surgical access route for craniopharyngiomas and was identified and used in clinical series. The aims of this study were to describe the characteristics that assist dissection and resection rates in endoscopic surgery of solid, cystic, and recurrent cases and their importance in the infrachiasmatic corridor in endoscopic surgery.

METHODS

One hundred operations on 84 patients with pathologically identified craniopharyngioma were included in the study. The MRI findings were evaluated, and the location of the lesions was classified as (1) infrasellar; (2) sellar; or (3) suprasellar. In the sagittal plane, we measured the longest diameter of cystic and solid components and the height of chiasm-sella. Images were assessed for the extent of resection and were classified as gross total resection. This was deemed as the absence of residual tumor and subtotal resection, which had residual tumor.

RESULTS

The infrasellar location was reported in 7/84 (8.3%) patients, the sellar location in 8/84 (9.5%), and the suprasellar location in 69/84 (82.1%) patients. The narrow and high chiasm-sella were observed in 28/69 (40.5%) and 41/69 patients (59.4%), respectively. The mean distance of the chiasm-sella was 9.46± 3.76. Gross total tumor resection was achieved in 60/84 (71.4%) and subtotal tumor resection was performed in 24/84 (28.6%) patients. The results revealed that suprasellar location (OR: 0.068; p = 0.017) and recurrent cases (OR: 0.011; p<0.001) were negative predictive factors on GTR. Increasing the experience (OR: 42,504; p = 0.001) was a positive predictor factor for GTR.

CONCLUSION

An EETS approach that uses the infrachiasmatic corridor is required for skull base lesions extending into the suprasellar area. The infrachiasmatic corridor can determine the limitations of endoscopic craniopharyngioma surgery. This corridor is a surgical safety zone for inferior approaches.

Craniopharyngiomas: Challenges and Controversies

Despite its benign histopathology, the treatment of craniopharyngioma remains one of the most formidable challenges faced by skull base surgeons. The technical challenges of tackling these complex central skull base lesions are paralleled by clinical challenges related to their unique tumor biology and the often-complex decision making required. In this article, we critically appraise the most recent literature to explore the challenges and controversies surrounding the management of these lesions. The role of curative resections and the shift in the surgical paradigm toward the multidisciplinary goal-directed management approach are discussed.

Craniopharyngiomas primarily affecting the hypothalamus

The concept of craniopharyngiomas (CPs) primarily affecting the hypothalamus, or "hypothalamic CPs" (Hy-CPs), refers, in a restrictive sense, to the subgroup of CPs originally developing within the neural tissue of the infundibulum and tuber cinereum, the components of the third ventricle floor. This subgroup, also known as infundibulo-tuberal CPs, largely occupies the third ventricle and comprises up to 40% of this pathological entity. The small subgroup of strictly intraventricular CPs (5%), lesions wholly developed within the third ventricle above an anatomically intact third ventricle floor, can also be included within the Hy-CP category. The remaining types of sellar and/or suprasellar CPs may compress or invade the hypothalamic region during their growth but will not be considered in this review. Hy-CPs predominantly affect adults, causing a wide range of symptoms derived from hypothalamic dysfunction, such as adiposogenital dystrophy (Babinski-Fröhlich's syndrome), diabetes insipidus (DI), abnormal diurnal somnolence, and a complex set of cognitive (dementia-like, Korsakoff-like), emotional (rage, apathy, depression), and behavioral (autism-like, psychotic-like) disturbances. Accordingly, Hy-CPs represent a neurobiological model of psychiatric disorders caused by a lesion restricted to the hypothalamus. The vast majority (90%) of squamous-papillary CPs belong to the Hy-CP category. Pathologically, most Hy-CPs present extensive and strong adhesions to the surrounding hypothalamus, usually formed of a thick band of gliotic tissue encircling the central portion of the tumor ("ring-like" attachment) or its entire boundary ("circumferential" attachment). CPs with these severe adhesion types associate high surgical risk, with morbidity and mortality rates three times higher than those for sellar/suprasellar CPs. Consequently, radical surgical removal of Hy-CPs cannot be generally recommended. Rather, Hy-CPs should be accurately classified according to an individualized surgery-risk stratification scheme considering patient age, CP topography, presence of hypothalamic symptoms, tumor size, and, most importantly, the CP-hypothalamus adhesion pattern.

Charles H. Frazier's craniopharyngioma treatment: the pivotal role of the transfrontal approach

Charles H. Frazier (1870-1936), one of the pioneers of neurosurgery in the US, is known worldwide for devising surgical procedures to relieve trigeminal neuralgia and intractable pain. Less well-known are his substantial contributions to understanding and treating pituitary and parahypophyseal lesions. Along with Bernard Alpers, he defined Rathke's cleft tumors as a different pathological entity from adenomas and hypophyseal stalk tumors (craniopharyngiomas [CPs]). The surgical challenge posed by CPs piqued Frazier's interest in these lesions, although he never published a complete account of his CP series. An examination of the Charles Frazier papers at the College of Physicians of Philadelphia allowed the authors to identify 54 CPs that he had treated during his career. In the early 1910s, Frazier developed the subfrontal approach, which would become the primary surgical route to access these lesions, providing better control of the adjacent vital neurovascular structures than the transsphenoidal route hitherto used. Nevertheless, strong adhesions between CPs and the third ventricle floor, the major reason underlying Frazier's disappointing results, moved him to advocate incomplete tumor removal followed by radiotherapy to reduce both the risk of hypothalamic injury and CP recurrence. This conservative strategy remains a judicious treatment for CPs to this day.

Craniopharyngioma treatment: an updated summary of important clinicopathological concepts

INTRODUCTION

Craniopharyngiomas (CPs) are benign histological tumors that may develop at different positions along the hypothalamic-pituitary axis. Their close, heterogenous relationship to the hypothalamus makes surgical removal challenging even though this remains the primary treatment strategy.

AREAS COVERED

This article presents a critical overview of the pathological and clinical concepts regarding CPs that should be considered when planning treatment. Thus, we have performed a comprehensive review of detailed CP reports published between 1839 and 2020.

EXPERT OPINION

CP surgery should pursue maximal tumor resection while minimizing the risk of injuring the hypothalamus. Therefore, surgical strategies should be individualized for each patient. Accurate assessment of presenting symptoms and preoperative MRI has proven useful to predict the type of CP-hypothalamus relationship that will be found during surgery. CPs with dense and extensive adhesions to the hypothalamus should be highly suspected when MRI shows the hypothalamus positioned around the mid-third of the tumor and an amputated upper portion of the pituitary stalk. Symptoms related to functional impairment of the infundibulo-tuberal area of the third ventricle floor, such as obesity/hyperphagia, Fröhlich's syndrome, diabetes insipidus, and/or somnolence, also indicate risky CP-hypothalamic adhesions. In these cases, limited tumor removal is strongly advocated followed by radiation therapy.

Percival S. Bailey: eminent scholar of neurosciences who revealed the workings of the hypothalamus through clinicopathological research on craniopharyngiomas

Percival S. Bailey (1892-1973) was a scholar, neuroscientist, neuropathologist, and neurosurgeon who made decisive contributions in the field of neuro-oncology. Far less known are his groundbreaking insights into understanding hypothalamic physiology through the study of craniopharyngiomas. As one of Harvey W. Cushing's most talented trainees, Bailey was instrumental in developing Cushing's project of a histologically based prognostic classification of brain tumors. He worked at Peter Bent Brigham Hospital on and off between 1919 and 1928, owing to frequent clashes with his mentor. A major cause of this long-term conflict was Bailey's 1921 experimental demonstration of the hypothalamic origin of diabetes insipidus and Fröhlich's syndrome. This finding challenged Cushing's view that both alterations were due to pituitary gland insufficiency. In a seminal monograph written with John F. Fulton in 1929, both authors provided the first comprehensive account of the specific hypothalamic disturbances caused by tumors that originated within the infundibulum and third ventricle. The methodical study of Cushing's craniopharyngioma specimens allowed Bailey to recognize the close contact between these lesions and hypothalamic nuclei, a key concept that Bailey originally advanced for proper surgical planning. This article aims to credit Bailey for his pioneering definition of craniopharyngiomas as tumors with a true intrahypothalamic position.

Surgical management of craniopharyngiomas in adult patients: a systematic review and consensus statement on behalf of the EANS skull base section

BACKGROUND AND OBJECTIVE

Craniopharyngiomas are locally aggressive neuroepithelial tumors infiltrating nearby critical neurovascular structures. The majority of published surgical series deal with childhood-onset craniopharyngiomas, while the optimal surgical management for adult-onset tumors remains unclear. The aim of this paper is to summarize the main principles defining the surgical strategy for the management of craniopharyngiomas in adult patients through an extensive systematic literature review in order to formulate a series of recommendations.

MATERIAL AND METHODS

The MEDLINE database was systematically reviewed (January 1970-February 2019) to identify pertinent articles dealing with the surgical management of adult-onset craniopharyngiomas. A summary of literature evidence was proposed after discussion within the EANS skull base section.

RESULTS

The EANS task force formulated 13 recommendations and 4 suggestions. Treatment of these patients should be performed in tertiary referral centers. The endonasal approach is presently recommended for midline craniopharyngiomas because of the improved GTR and superior endocrinological and visual outcomes. The rate of CSF leak has strongly diminished with the use of the multilayer reconstruction technique. Transcranial approaches are recommended for tumors presenting lateral extensions or purely intraventricular. Independent of the technique, a maximal but hypothalamic-sparing resection should be performed to limit the occurrence of postoperative hypothalamic syndromes and metabolic complications. Similar principles should also be applied for tumor recurrences. Radiotherapy or intracystic agents are alternative treatments when no further surgery is possible. A multidisciplinary long-term follow-up is necessary.

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.

Harvey Cushing's craniopharyngioma treatment: Part 2. Surgical strategies and results of his pioneering series

OBJECTIVE

Harvey Cushing (1869-1939) developed pioneering surgical techniques for craniopharyngioma (CP) removal. This study exhaustively analyzes the pathological variables and surgical strategies that influenced Cushing's results in his entire series of CP patients.

METHODS

The CP records from Cushing's Brain Tumor Registry were carefully reviewed, as were his CP cases published in medical monographs and scientific reports.

RESULTS

One hundred twenty-four tumors with characteristics typical of CP comprise Cushing's entire series (CP124). Cushing performed 198 surgical procedures in the patients in whom these tumors were treated, with a 23% mortality rate within the first 2 months after surgery. Three periods in Cushing's CP surgical career can be differentiated: an early period (1901-1917, 39 patients) characterized by his use of the transsphenoidal approach and limited cyst drainage procedures, an intermediate period (1919-1925, 42 patients) in which the subfrontal approach was the standard procedure and maximal removal was attempted, and a late period (1926-1932, 43 patients) characterized by the use of air ventriculography for topographical diagnosis and limited resections via a transventricular approach. Among Cushing's CP series were 92 cases that were pathologically verified (CP92). In this subcohort, the unilateral subfrontal approach was predominantly used (72% of cases), followed by the transsphenoidal (15%) and frontal transcortical-transventricular (8%) approaches. Drainage of the CP cystic component or partial excision of the solid component was achieved in 61% of the cases, subtotal removal in 23%, and macroscopic total removal in 10%. Satisfactory outcomes were obtained in 55% of the patients in CP92, whereas poor outcomes and/or death related to hypothalamic injury was observed in 28%. Postoperative symptoms related to hypothalamic dysfunction occurred 53% of the time. The subfrontal approach yielded the highest rates of radical removal (p < 0.001) and good outcomes (p = 0.01). Partial removals were associated with the highest rates of poor outcomes, including death (p = 0.009). Cushing's removal of CPs with a primary infundibulo-tuberal topography or showing third ventricle invasion was associated with the highest rates of hypothalamic injury (p < 0.001) and the worst outcomes (p = 0.009).

CONCLUSIONS

Harvey Cushing's techniques and surgical philosophy varied substantially throughout his career. The experience he gained with this large CP series made him aware of the importance of limiting the extent of tumor removal and leaving untouched the tumor portion strongly adhered to the hypothalamus.

Is Gross Total Resection Reasonable in Adults with Craniopharyngiomas with Hypothalamic Involvement?

OBJECTIVE

The treatment of hypothalamus-invading craniopharyngiomas, based on pediatric experience, is subtotal resection (STR) with radiotherapy. This strategy sometimes leads to uncontrollable tumor progression. In adults, with the use of endoscopic endonasal surgery (EES), does removing the hypothalamic part of the tumor-whenever possible-compromise the outcome of the patients?

METHODS

We included adults with craniopharyngioma treated by a first EES in 2008-2016 by senior neurosurgeon (E.J.). Endocrine, ophthalmologic, and hypothalamic data were retrospectively collected, including body mass index (BMI), cognitive and social status, with a systematic follow-up interview. Magnetic resonance imaging scans were graded according to Puget classification: 0, no hypothalamic involvement; 1, hypothalamic displacement; and 2, hypothalamic involvement. Grade 2 tumors were separated into gross total resection (GTR) or STR.

RESULTS

We included 22 patients aged 18-79 years. Presenting symptoms were visual (14, 64%), endocrine dysfunction (10, 45%), BMI >30 (8, 36%), and cognitive/psychiatric impairment (9, 41%). Fourteen (64%) were grade 2 craniopharyngiomas. GTR was performed in 14 (64%) patients. Postoperatively, 12/14 (86%) cases improved visually, and 20 (91%) needed hormone replacement therapy. There was no difference in BMI evolution in the GTR versus STR group, cognitive status was stable or improved in all patients except 1; 4/8 patients with STR experienced progression needing adjuvant treatment versus no patient with GTR.

CONCLUSIONS

EES GTR of grade 2 craniopharyngiomas does not cause major hypothalamic worsening, in contrast with children operated by cranial approaches. The surgeon's experience is key in deciding when to stop the dissection. Offering GTR whenever possible aims at avoiding tumor progression and radiotherapy.