Jakob Erdheim (1874–1937): father of hypophyseal-duct tumors (craniopharyngiomas)

Advances in the treatment of Adamantinomatous craniopharyngioma: How to balance tumor control and quality of life in the current environment: a narrative review

Adamantinomatous craniopharyngioma (ACP) presents a significant challenge to neurosurgeons despite its benign histology due to its aggressive behavior and unique growth patterns. This narrative review explores the evolving landscape of ACP treatments and their efficacy, highlighting the continuous development in therapeutic approaches in recent years. Traditionally, complete resection was the primary treatment for ACP, but surgical -related morbidity have led to a shift. The invasive nature of the finger-like protrusions in the histological structure results in a higher recurrence rate for ACP compared to papillary craniopharyngioma (PCP), even after complete macroscopic resection. Given this, combining subtotal resection with adjuvant radiotherapy has shown potential for achieving similar tumor control rates and potentially positive endocrine effects. Simultaneously, adjuvant treatments (such as radiotherapy, intracystic treatment, and catheter implantation) following limited surgery offer alternative approaches for sustained disease control while minimizing morbidity and alleviating clinical symptoms. Additionally, advances in understanding the molecular pathways of ACP have paved the way for targeted drugs, showing promise for therapy. There is a diversity of treatment models for ACP, and determining the optimal approach remains a subject of ongoing debate in the present context. In order to achieve a good-term quality of life (QOL), the main goal of the cyst disappearance or reduction of surgical treatment is still the main. Additionally, there should be a greater emphasis on personalized treatment at this particular stage and the consideration of ACP as a potentially chronic neurosurgical condition. This review navigates the evolving landscape of ACP therapies, fostering ongoing discussions in this complex field.

The Pioneer Neuropharmacologist Alfred Fröhlich (1871-1953) and the Origins of Neuroendocrinology: A Sesquicentennial Remembrance

The birth of neuroendocrinology as a scientific discipline is traced back to 1900-1901, when Joseph Babinski, Alfred Fröhlich, and Harvey Cushing independently identified adiposogenital dystrophy (Fröhlich syndrome), and related gonadal underdevelopment and obesity to a tumor near the pituitary gland. This discovery prompted decades of research into the brain mechanisms responsible for the control of peripheral metabolism and endocrine functions. On the occasion of the 150th anniversary of Fröhlich's birth, this study traces the origins of his intellectual formation and his association with renowned contemporaries in Austria, England, Italy, and finally Cincinnati, Ohio, where he sought refuge after Austria's annexation by Nazi Germany. Fröhlich interacted with seminal figures in biomedicine, including Lothar von Frankl-Hochwart, Hans Horst Meyer, Ernst Peter Pick, Harvey Cushing, John Newport Langley, and the Nobel laureates Charles Scott Sherrington and Otto Loewi. Alfred Fröhlich, one of the 20th century's most emblematic physicians, left his mark on neurophysiology and neuropharmacology with important works, and published authoritative manuals of drug dispensing and clinical therapy. He confronted the calamities of two World Wars with remarkable resilience like many of his Viennese colleagues who, overcoming the constraints of National Socialism, settled overseas to fulfil their calling as physicians, researchers, and teachers.

Duct-like Recess in the Infundibular Portion of Third Ventricle Craniopharyngiomas: An MRI Sign Identifying the Papillary Type

BACKGROUND AND PURPOSE

Papillary craniopharyngiomas (PCPs) are particularly challenging lesions requiring accurate diagnosis to plan the best therapy. Our aim was to define a narrow duct-like recess identified on MR imaging at the base of papillary craniopharyngiomas with a strict third ventricle location.

MATERIALS AND METHODS

A duct-like recess at the infundibular portion of craniopharyngiomas was observed on conventional T1WI and T2WI in 3 strict third ventricle papillary craniopharyngiomas in our craniopharyngioma series (n = 125). We systematically investigated this finding on the MR imaging of 2582 craniopharyngiomas and 10 other categories of third ventricle tumors (n = 690) published in the modern era (1986-2020). The diagnostic value and significance of this finding are addressed.

RESULTS

The duct-like recess was recognized in 52 papillary craniopharyngiomas, including 3 of our own cases, as a narrow canal-shaped cavity invaginated at the tumor undersurface, just behind the optic chiasm. This structure largely involves papillary craniopharyngiomas with a strict third ventricle topography (96%), follows the same diagonal trajectory as the pituitary stalk, and finishes at a closed end. The duct-like recess sign identifies the papillary craniopharyngioma type with a specificity of 100% and a sensitivity of 38% in the overall craniopharyngioma population. This finding can also establish the strictly intra-third ventricle location of the lesion with a 90% specificity and 33% sensitivity. These recesses appear as hypointense circular spots on axial/coronal T1WI and T2WI. Their content apparently corresponds to CSF freely flowing within the suprasellar cistern.

CONCLUSIONS

The presence of a duct-like recess at the infundibular portion of a third ventricle tumor represents a distinctive hallmark of papillary craniopharyngiomas that can be used as a simple MR imaging sign to reliably diagnose these lesions.

Duct-like diverticulum at the base of third ventricle tumors: a morphological signature diagnostic of papillary craniopharyngioma

This study describes and characterizes a narrow, hollow tubular structure, termed as duct-like diverticulum (DV), found specifically at the basal midline of papillary craniopharyngiomas (PCPs) located within the third ventricle (3V). The presence of this structure was systematically investigated on autopsy studies and magnetic resonance imaging (MRI) scans of 3536 craniopharyngioma (CP) cases published in the medical literature from 1911 to 2021, as well as in other twelve 3V tumor categories (n = 1470 cases). A basal DV was observed in a total of 50 PCPs, including two of our own cases. This DV corresponds to a tubular-shaped recess invaginated at the midline bottom of the tumor, following the same angled trajectory as the pituitary stalk. It can be easily seen as a hypointense linear structure on T1- and T2-weighted MRI scans, with two main length types: long DVs (74%), which reach the tumor center, and short DVs (26%), which penetrate the tumor only a few millimeters. The DV sign identifies the papillary CP type with a specificity of 100% and a sensitivity of 33% in the overall CP population. This finding also serves to establish the strictly intra-3V location of the lesion with a 95% specificity and 42% sensitivity among papillary CPs. No similar basal DV was found in adamantinomatous CPs nor among other categories of strictly 3V tumors. Consequently, the presence of a diverticulum in a 3V tumor represents a morphological signature pathognomonic of the papillary type and a valuable sign to reliably define the strictly 3V topography.

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.

An Infundibular Unidentified Object (IUO): a new pituitary stalk marker?

PURPOSE

Measurement of the pituitary stalk (PS) diameter does not always solve the issue of minimal PS thickening. A previously undescribed image is found at the infundibular level on high resolution thin section T2W MRI in a large number of normal individuals. We speculate that this image-whose exact origin is still unknown-may serve as a marker of the normal infundibulum.

METHODS

In the last 6 months, 350 consecutive adult patients suspected of sellar pathology or controlled after medical or surgical treatment prospectively underwent a pituitary MRI including a sagittal T2W high resolution sequence. One hundred twelwe patients presenting a pituitary mass with suprasellar extension or those whose PS was not entirely visible were excluded.

RESULTS

A short focal annular T2 hypointense thickening of the wall of the infundibular recess of the third ventricle, more pronounced anteriorly was found in 151/238 patients. Additionally, a more or less tiny ventral extension was demonstrated on sagittal T2W sequence in 105/151 patients. These images were not identified on T1W or on T1W gadolinium enhanced sequences. The ring-like infundibular thickening and/or its ventral extension were not identified in 87/238 patients; in 43/87 of these patients the PS was found severely stretched mainly in case of primary or secondary empty sella. If patients with empty sella were excluded, our finding was observed in 194/238 cases, i.e. in 82%.

CONCLUSIONS

A detailed appearance of the PS on T2W MRI is described for the first time. A previously unreported T2W hypointense annular focal image prolonged by a tiny spicular or nodular ventral bud is found at the lower part of the infundibulum in a majority of normal patients, but not if the PS is stretched such as in empty sella. This image has to be recognized as a normal anatomical landmark. The possible origin of this image is discussed but not totally elucidated. An ongoing research will demonstrate or not if this image may serve as a marker to improve the early diagnosis of PS lesions.

Update on management of craniopharyngiomas

PURPOSE/INTRODUCTION

Craniopharyngiomas are locally-aggressive tumors arising along the hypothalamic-pituitary axis. Treatment is nuanced as a result of their proximity and adherence to vital neurovascular structures and responsiveness to surgery, radiation and, in some cases, chemotherapy.

METHODS

We reviewed the literature discussing the current state of knowledge regarding craniopharyngioma biology and therapy.

RESULTS

Recent advances in endoscopic endonasal surgery (EEA) have made surgery a safer and more effective option. While cure may be achieved with gross total resection (GTR), when felt to be too risky, a subtotal resection followed by radiation is often a more prudent strategy, particularly in children with hypothalamic invasion. Data on long-term outcome are mostly derived from older studies in which a craniotomy, rather than EEA, was performed. Long-term EEA outcome studies are lacking. Enhanced knowledge of the biological basis of papillary CPs has led to novel medical treatments for BRAFv^600E variants that appear to be effective.

CONCLUSION

Endoscopic technology has improved surgical results for craniopharyngiomas and expanded the indications for the transsphenoidal approach. The goal of CP surgery goal is maximal safe resection to achieve cure, but subtotal resection and radiation may be equally effective. Early diagnosis of specific variants will facilitate enrollment in promising medical trials.

Primary Tumors of the Pituitary Gland: Radiologic-Pathologic Correlation

Primary tumors of the pituitary gland are the second most common histologic category of primary central nervous system tumors across all age groups and are the most common in adolescents to young adults, despite originating from a diminutive endocrine gland that is often described as "about the size of a pea." The vast majority of these represent primary tumors of the adenohypophysis, specifically pituitary adenomas, which can be either functional or silent with regard to hormone hypersecretion. According to the fourth edition of the World Health Organization classification of endocrine tumors, published in 2017, cellular lineage and immunohistochemical stains for pituitary hormones and/or transcription factors help with making the correct pathologic diagnosis. From a radiologic standpoint, microadenomas pose challenges for accurate detection and avoiding false-negative or false-positive results, while macroadenomas pose challenges from local mass effect on surrounding structures. Pituitary carcinoma and pituitary blastoma also arise from the adenohypophysis and are characterized by metastatic disease and infantile presentation, respectively. While primary tumors of the adenohypophysis are common, a second category comprising primary tumors of the Rathke pouch (ie, craniopharyngioma) are uncommon, and a third category comprising primary tumors of the neurohypophysis (eg, pituicytoma) are rare. The authors review all three categories of pituitary tumors, with emphasis on radiologic-pathologic correlation, including the typical neuroimaging, histologic, and molecular features that may point toward a specific diagnosis. Work of the U.S. Government published under an exclusive license with the RSNA.

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.

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.

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.

Biological Behaviour of Craniopharyngiomas

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

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

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 1. Identification and clinicopathological characterization of this challenging pituitary tumor

OBJECTIVE

Harvey Cushing (1869–1939) coined the term “craniopharyngioma” (CP) in 1929 to describe a kaleidoscopic group of epithelial tumors involving the hypothalamic-pituitary axis. Throughout his career, he endured a long struggle to accurately diagnose and safely remove these complex lesions, and his resulting surgical series has never before been analyzed in depth. The authors here conduct such an analysis.

METHODS

In this study, the authors retrospectively examined the CP patient records available in the Cushing Brain Tumor Registry, as well as those CP cases reported by Cushing in medical monographs and scientific reports.

RESULTS

Cushing’s CP series comprises a total of 124 tumors (CP124) compatible with a CP diagnosis. Among this series are 92 cases that could be pathologically verified (CP92). This subcohort showed a bimodal age distribution (41% aged ≤ 19 years old) and a balanced sex distribution. Clinical evolution up to diagnosis was longer than 3 years in half of the patients. Typical symptoms found at diagnosis were severe headache (94%), visual deficits (97%), panhypopituitarism (76%), psychiatric disturbances (47%), and abnormal somnolence (47%). The highest rate of endocrine deficits occurred in patients younger than 19 years of age (p < 0.001), whereas hypothalamic disturbances were observed mainly in adults between 30 and 49 years (p = 0.02). Hydrocephalus was present in 63% of the patients, predominantly involving the younger subgroup (p < 0.001). Preoperative diagnosis was based on clinical signs, funduscopic exams, and skull radiographs, the latter study showing suprasellar calcifications in 64% of cases. The majority of tumors (61%) had developed within the third ventricle (3V) or had invaded it. The adamantinomatous histological variant was the predominant one (73%). Squamous-papillary CPs occurred only in adults older than 40 years of age (p < 0.001). Strong CP adherences to the hypothalamus were demonstrated in 63% of cases. The infundibulo-tuberal and sellar/suprasellar–3V CP topographies were associated with the highest rates of hypothalamic dysfunction before surgery (p < 0.001), surgical hypothalamic injury (p < 0.001), and severe postoperative morbidity and/or mortality (p = 0.009). Both topographies showed the strongest adherences to the hypothalamus and 3V (p < 0.001).

CONCLUSIONS

Cushing’s CP series comprises severely ill patients with tumors in the late stages of progression, with a high rate of tumors developing primarily within the hypothalamus (infundibulo-tuberal CPs) or invading this structure from the sellar/suprasellar regions. Craniopharyngioma topography was the fundamental variable influencing the clinical manifestations, tumor features, and patient outcomes in this series.

Learning from cases: Analysis of two cases of craniopharyngioma from the 19 th to the 21 st centuries

This manuscript describes the study of two cases of craniopharyngioma, which have been examined repeatedly over three separate centuries. This includes analysis by Josef Engel in 1839, who sought to uncover the physiological role of the pituitary gland; Jacob Erdheim in 1904, who initially described the disease we now call craniopharyngioma, and recent high resolution MRI and micro-CT imaging and attempted DNA analyses of the tumours. The cases highlight how, rightly or wrongly, our interpretation of data is shaped by the technologies, methodologies and prevailing theories of a given time.

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.

Intrachiasmatic craniopharyngioma: Assessment of visual outcome with optical coherence tomography after complete surgical removal

Background:

Optic chiasm invasion by a craniopharyngioma (CP) is exceptional. Surgical treatment of intrachiasmatic CPs associates a high risk of chiasm injury, which should be properly addressed before surgery.

Case Description:

We present a 46-year-old woman admitted to the hospital with low visual acuity (0.1 in the right eye and 0.5 in the left) and a severe defect in her visual fields, in addition to headaches, diabetes insipidus, and a long-term depressive disorder. Her visual deficit progressed from a right homonymous temporal inferior quadrantanopia to an almost complete loss of vision in both eyes that only spared the upper nasal quadrants. Brain MRI showed a rounded third ventricle tumor with a potbelly expansion of the optic chiasm, suggesting chiasm invasion by the tumor. Optical coherence tomography (OCT) showed the thinning of the retinal nerve fiber layer (RNFL) in the superior and temporal wedges of the right eye and in the temporal wedge of the left one. The tumor was completely removed by employing a frontotemporal craniotomy and a translamina terminalis approach. Histological analysis showed a squamous-papillary CP. Postoperatively, a significant worsening of the visual defect was evidenced on the perimetry, which was related to a marked RNFL atrophy measured with OCT, as compared to the preoperative study. The poor long-term visual outcome in this patient correlated well with the results of postoperative OCT.

Conclusions:

Preoperative analysis of retinal atrophy with optic coherence tomography allows a reliable assessment of the patient's visual outcome in CPs involving the optic chiasm.

Cystic tumors of the pituitary infundibulum: seminal autopsy specimens (1899 to 1904) that allowed clinical-pathological craniopharyngioma characterization

A heterogeneous group of epithelial cystic tumors developed at the infundibulum and the third ventricle disconcerted pathologists at the dawn of the twentieth century. Very little was known at that time about the physiological role played by the pituitary gland, and there was almost complete ignorance regarding the function of the hypothalamus. Acromegaly, or enlargement of acral body parts, described in 1886 by Pierre Marie, was the only disease linked to primary hypertrophies of the pituitary gland, known as "pituitary strumas". A growing number of young patients manifesting an unexplained combination of physical and mental symptoms, including absent or delayed sexual maturation, progressive obesity, abnormal somnolence, and dementia-like changes in behavior were reported to present large solid-cystic tumors which characteristically expanded within the infundibulum and third ventricle, above an anatomically intact pituitary gland. Between 1899 and 1904, five seminal autopsy studies from different countries thoroughly described the anatomical relationships and histological features of this newly recognized type of infundibular tumors. These cases were instrumental in fostering the systematic investigation of similar lesions by the Austrian pathologist Jakob Erdheim (1874-1937), who in 1904 was able to classify these infundibulo-tuberal cysts under the common category of hypophyseal duct tumors. The pioneering American neurosurgeon Harvey Cushing (1869-1939) unsuccessfully attempted to surgically remove one of these cysts, for the first time in history, in 1902. The term "craniopharyngioma", chosen by Cushing in 1929 to designate these lesions, would eventually prevail over Erdheim's more accurate denomination, which linked their origin to squamous cell remnants derived from the embryological structures that give rise to the pituitary gland. This paper presents a comprehensive, renewed account of the five clinical-pathological reports which laid the groundwork for the proper clinical diagnosis, topographic conceptualization and pathological categorization of craniopharyngiomas.

Can tissue biomarkers reliably predict the biological behavior of craniopharyngiomas? A comprehensive overview

BACKGROUND

The growing interest in the molecular and genetic alterations of craniopharyngiomas (CPs) is embodied in recent studies revealing insights into the CP tumorigenesis and identifying novel molecular pathways amenable of targeted therapies. The actual impact of this new information, however, remains inconclusive.

METHODS

We present a comprehensive review of the accumulated knowledge on molecular biology of CPs and a critical analysis on the strengths and weaknesses of the studies focused on CP molecular/genetic alterations published to date.

RESULTS

A thorough analysis of the alterations of β-catenin/CTNNB1 and BRAF genes investigated in 1123 CP cases included in 27 studies, showed that, on average, CTNNB1 mutations were present in two-thirds of adamantinomatous CPs and BRAF mutations in 90% of papillary CPs. Their role as oncogenic drivers has not been well established. Although rare, coexistence of both mutations may occur. The involvement of pituitary stem cells in human CP tumorigenesis is still uncertain. Expression of stem markers in human CP samples predominantly occurred along the CP border in contact with brain tissue. Finally, none of the various molecular alterations which have been proposed as markers for CP recurrence can be used today as reliable predictors of the CP behavior.

CONCLUSIONS

The isolated evaluation of CPs' molecular or genetic profiles that do not take into consideration fundamental pathological and therapeutic factors, specifically the tumor topography and the degree of tumor removal, may actually generate confusion regarding the reliability of some biomarkers to predict the CP biological behavior.

Craniopharyngioma adherence: a comprehensive topographical categorization and outcome-related risk stratification model based on the methodical examination of 500 tumors

OBJECTIVE Craniopharyngioma (CP) adherence strongly influences the potential for achieving a radical and safe surgical treatment. However, this factor remains poorly addressed in the scientific literature. This study provides a rational, comprehensive description of CP adherence that can be used for the prediction of surgical risks associated with the removal of these challenging lesions. METHODS This study retrospectively analyzes the evidence provided in pathological, neuroradiological, and surgical CP reports concerning 3 components of the CP attachment: 1) the intracranial structures attached to the tumor; 2) the morphology of the adhesion; and 3) the adhesion strength. From a total of 1781 CP reports published between 1857 and 2016, a collection of 500 CPs providing the best information about the type of CP attachment were investigated. This cohort includes autopsy studies (n = 254); surgical studies with a detailed description or pictorial evidence of CP adherence (n = 298); and surgical CP videos (n = 61) showing the technical steps for releasing the attachment. A predictive model of CP adherence in hierarchical severity levels correlated with surgical outcomes was generated by multivariate analysis. RESULTS The anatomical location of the CP attachment occurred predominantly at the third ventricle floor (TVF) (54%, n = 268), third ventricle walls (23%, n = 114), and pituitary stalk (19%, n = 94). The optic chiasm was involved in 56% (n = 281). Six morphological patterns of CP attachment were identified: 1) fibrovascular pedicle (5.4%); 2) sessile or patch-like (21%); 3) cap-like (over the CP top, 14%); 4) bowl-like (around the CP bottom, 13.5%); 5) ring-like (encircling central band, 19%); and 6) circumferential (enveloping the entire CP, 27%). Adhesion strength was classified in 4 grades: 1) loose (easily dissectible, 8%); 2) tight (requires sharp dissection, 32%); 3) fusion (no clear cleavage plane, 40%); and 4) replacement (loss of brain tissue integrity, 20%). The types of CP attachment associated with the worst surgical outcomes are the ring-like, bowl-like, and circumferential ones with fusion to the TVF or replacement of this structure (p < 0.001). The CP topography is the variable that best predicts the type of CP attachment (p < 0.001). Ring-like and circumferential attachments were observed for CPs invading the TVF (secondary intraventricular CPs) and CPs developing within the TVF itself (infundibulo-tuberal CPs). Brain invasion and peritumoral gliosis occurred predominantly in the ring-like and circumferential adherence patterns (p < 0.001). A multivariate model including the variables CP topography, tumor consistency, and the presence of hydrocephalus, infundibulo-tuberal syndrome, and/or hypothalamic dysfunction accurately predicts the severity of CP attachment in 87% of cases. CONCLUSIONS A comprehensive descriptive model of CP adherence in 5 hierarchical levels of increased severity-mild, moderate, serious, severe, and critical-was generated. This model, based on the location, morphology, and strength of the attachment can be used to anticipate the surgical risk of hypothalamic injury and to plan the degree of removal accordingly.

Norman M. Dott, master of hypothalamic craniopharyngioma surgery: the decisive mentoring of Harvey Cushing and Percival Bailey at Peter Bent Brigham Hospital

Norman McOmish Dott (1897-1973) developed surgical neurology in Edinburgh, Scotland, and was a scholar of worldwide renown. One of Dott's most notable contributions to neurosurgery was his understanding of hypothalamic physiology, mostly acquired through the comprehensive study of patients with lesions involving this region of the diencephalon, particularly craniopharyngiomas (CPs). Recognition of symptoms caused by hypothalamic disturbances allowed him to predict the accurate anatomical relationships between CPs and the hypothalamus, despite the rudimentary radiological methods available during the 1930s. His sophisticated knowledge permitted Dott to perform radical removals of CPs originating within the third ventricle floor with acceptable success. Between 1934 and 1937, he operated on 4 CP cases originating in the hypothalamus, achieving a satisfactory postoperative outcome in 3 of the 4 patients. Aware of the strong attachment of hypothalamic CPs to the infundibulo-tuberal area, Dott used a double transbasal and transventricular approach to these lesions, a strategy providing an optimal view and control of the tumor boundaries. The decisive mentorship of several legendary figures of physiology and neurosurgery greatly influenced Dott's surgical evolution. The experimental pituitary gland work he performed with Sir Edward Sharpey-Schäfer at the beginning of his career stirred Dott's curiosity about the issue of hypothalamus-pituitary relationships. As a result, he decided to move to Peter Bent Brigham Hospital (Boston, Massachusetts) in 1923, to train in neurosurgery and neuropathology under the guidance of the leaders in these fields, Harvey Williams Cushing (1869-1939) and Percival Sylvester Bailey (1892-1973). They inspired the young Dott and shared with him their clinical and pathological expertise, in addition to their surgical strategies for best approaching and removing these challenging tumors. In time, Dott would come to surpass his mentors. This paper aims to credit Norman M. Dott for his decisive, modern contributions to hypothalamic CP surgery.