Junxiang Peng

Intraventricular craniopharyngioma: morphological analysis and outcome evaluation of 17 cases

PurposeThere is still some confusion with regard to the tumor–third ventricle floor (3rd VF) relationship of craniopharyngiomas located exclusively within the third ventricle. This study aims to provide some evidence to clarify the growth pattern of intraventricular craniopharyngiomas (IVC), and to summarize the surgical strategy and outcome.MethodsSeventeen cases of IVC were reviewed retrospectively in relation to preoperative imaging, clinical presentation, intraoperative findings, tumor pathology, and surgical outcome. The tumor–3rd VF relationship and the tumors stratification were analyzed based on intraoperative inspection and histology.FindingsVariable adherence patterns of IVC to the 3rd VF were found, which were classified as (a) purely IVC with pedicle attachment to 3rd VF (two cases), (b) intra-3rd VF tumors with wide-based attachment but a dissectible tumor boundary (seven cases), and (c) intra-3rd VF tumors with an undissectible wide, tight attachment (eight cases). Histological analysis revealed that both of the two cases with growth pattern “a” intruded into the third ventricular cavity without a covering layer of neural tissue (which only exists in the squamous-papillary subtype). Tumors with growth pattern “b” and “c,” in contrast, were noted to have a thin layer of neural tissue. This occurred in both subtypes (11 adamantinomatous, 4 papillary). Total removal was accomplished in all tumors demonstrating growth pattern “a” and “b.” There was also better preservation of the 3rd VF and consequently a better outcome. On the other hand, total removal was only achieved in 50% of tumors showing growth pattern “c” including one mortality. No recurrence has been encountered in patients whose tumors were totally removed.ConclusionVariable adherence patterns and tumor subtypes were observed in IVCs, which were correlated to the tumor pathology, resectability, and subsequent prognosis.

Growth patterns of craniopharyngiomas: clinical analysis of 226 patients

OBJECT Craniopharyngiomas (CPs) are rare epithelial tumors that are often associated with an enigmatic and unpredictable growth pattern. Understanding the growth patterns of these tumors has a direct impact on surgical planning and may enhance the safety of radical tumor removal. The aim of this study was to analyze the growth patterns and surgical treatment of CPs with a focus on the involvement of the hypothalamopituitary axis and the relationship of the tumor to the arachnoid membrane and surrounding structures. METHODS Clinical data from 226 consecutive patients with primary CP were retrospectively reviewed. Tumor location and the relationship of the tumor to the third ventricle floor and the pituitary stalk were evaluated using preoperative MRI and intraoperative findings. A topographic classification scheme was proposed based on the site of tumor origin and tumor development. The clinical relevance of this classification on patient presentation and outcomes was also analyzed. RESULTS The growth of CPs can be broadly divided into 3 groups based on the site of tumor origin and on tumor-meningeal relationships: Group I, infrasellar/infradiaphragmatic CPs (Id-CPs), which mainly occurred in children; Group II, suprasellar subarachnoid extraventricular CPs (Sa-CPs), which were mainly observed in adults and rarely occurred in children; and Group III, suprasellar subpial ventricular CPs (Sp-CPs), which commonly occurred in both adults and children. Tumors in each group may develop complex growth patterns during vertical expansion along the pituitary stalk. Tumor growth patterns were closely related to both clinical presentation and outcomes. Patients with Sp-CPs had more prevalent weight gain than patients with Id-CPs or Sa-CPs; the rates of significant weight gain were 41.7% for children and 16.7% for adults with Sp-CPs, 2.2% and 7.1% for those with Id-CPs, and 12.5% and 2.6% for those with Sa-CPs (p < 0.001). Moreover, patients with Sp-CPs had increased hypothalamic dysfunction after radical removal; 39% of patients with Sp-CPs, 14.5% with Id-CPs, and 17.4% with Sa-CPs had high-grade hypothalamic dysfunction in the first 2 postoperative years (p < 0.001). CONCLUSIONS The classification of CPs based on growth pattern may elucidate the best course of treatment for this formidable tumor. More tailored, individualized surgical strategies based on tumor growth patterns are mandatory to provide long-term tumor control and to minimize damage to hypothalamic structures. Differences in the distribution of growth patterns between children and adults imply that hierarchical comparison is necessary when investigating outcomes and survival across treatment paradigms in patients with CP.

The impact of the site of origin and rate of tumour growth on clinical outcome in children with craniopharyngiomas

Objectives  Data on many predictors of hypothalamic–pituitary axis dysfunction associated with childhood craniopharyngioma (CP) are rather inconsistent, probably reflecting the variable but as yet unclarified growth pattern of these tumours. The aim of this study was to define the determinative role of tumour growth pattern on hypothalamic–pituitary axis function and outcomes for childhood CPs.

Anatomical and histological study of Liliequist's membrane: with emphasis on its nature and lateral attachments.

PurposeIn previous studies, some disagreements regarding the nature (inner or outer arachnoid membrane) and lateral boundaries (temporal uncus or tentorial edge) of Liliequist’s membrane remain. The aim was to clarify whether Liliequist’s membrane is an inner or outer arachnoid membrane, and the distribution of Liliequist’s membrane with emphasis on its lateral attachments.MethodsLiliequist’s membrane was investigated by microsurgical dissection in 24 formalin-fixed adult cadaver heads and by histological sections of sellar–suprasellar specimens from another four formalin-fixed adult cadaver heads.ResultsThe results obtained in the present study indicated that 1) Liliequist’s membrane arises from the basal arachnoid membrane and has two components: a basal part comprising a folding inner layer of the arachnoid mater and an attaching part consisting of accumulated arachnoid trabeculae; 2) similar histological features are also present in other inner arachnoid membranes with attachments on basal arachnoid membrane, demonstrating Liliequist’s membrane is an inner arachnoid membrane; 3) laterally, Liliequist’s membrane attaches to the anterior tentorial edge constantly and to the mesial temporal uncus in more than half; 4) the oculomotor nerve courses above Liliequist’s membrane and is fixed on Liliequist’s membrane by the oculomotor membrane, which can also attach on temporal uncus and should be differentiated from the true temporal attachments of Liliequist’s membrane.ConclusionLiliequist’s membrane is an inner rather than outer arachnoid membrane. Understanding of its individual variation and topographic relationships with surrounding neurovascular and arachnoid structures is important for neurosurgical practice.

The distribution of arachnoid membrane within the velum interpositum

BackgroundThere is as yet little knowledge as to the arachnoid architecture within the velum interpositum. The aim of this study was to clarify the distribution of the arachnoid membrane within the velum interpositum and its relationship with the arachnoid envelope over the pineal region.MethodsIn seven adult cadaver heads, histological sections of the third ventricle roof, stained with Masson’s trichrome stains, were studied under light microscopy.ResultsWithin the velum interpositum, there are two arachnoid layers. The dorsal layer of arachnoid membrane envelops the internal cerebral veins and fixes them to the surrounding tela choroidea as well as the ventral arachnoid layer. The ventral layer of arachnoid membrane is a direct anterior extension of the arachnoid envelope over the pineal region and covers the midline inferior layer of tela choroidea. Both arachnoid layers end near the foramen of Monro.ConclusionsThe membranous roof of the third ventricle comprises two layers of the tela choroidea and two arachnoid layers. These two arachnoid layers are derived from the arachnoid envelope over the pineal region.

TREM-1 expression in craniopharyngioma and Rathke’s cleft cyst: its possible implication for controversial pathology

Whether a mixed type of craniopharyngioma (CP) exists and whether papillary craniopharyngioma (pCP) is on a histopathological continuum with Rathkes cleft cyst (RCC) remain controversial. Herein, we examined the expression and localization of β-catenin, BRAF p.V600E (V600E), and triggering receptor expressed on myeloid cells-1 (TREM-1) in 58 samples including 20 pCPs, 26 adamantinomatous craniopharyngiomas (aCP), and 12 RCCs. Five aCPs were diagnosed with mixed type CPs and the remaining 21 cases were pure aCPs. Four of the 12 RCCs presented with significant squamous epithelium (SE). V600E immunoreactivity was observed in all pCPs in the cytoplasm, but not in the nuclei. aCPs and RCCs, including mixed type CP, did not express V600E. Nuclear β-catenin translocation was detected exclusively in aCPs. TREM-1 was expressed in pCPs. Additionally, TREM-1 expression was detected in the SE of 5 “mixed type” CPs, while it was absent in pure aCPs. TREM-1 was expressed in 4 RCCs with SE, but not in the remaining 8 RCCs. TREM-1 mRNA levels were compared in cultured pCP and aCP cells. TREM-1 mRNA level was significantly (p < 0.001; up to 4.045 fold) higher in pCPs than in aCPs. Western blotting revealed a significantly (p < 0.001; up to 7.19 fold) lower level of TREM-1 expression in aCP cells compared to that in pCP cells. Our findings further supported that RCC and pCP may represent two ends of a morphological spectrum. A variant showing overlapping histological features of aCP and pCP should not be considered as a mixed type.

Origin of craniopharyngiomas: implications for growth pattern, clinical characteristics, and outcomes of tumor recurrence

OBJECT Craniopharyngiomas are associated with a high rate of recurrence. The surgical management of recurrent lesions has been among the most challenging neurosurgical procedures because of the craniopharyngiomas complex topographical relationship with surrounding structures. The aim of this study was to define the determinative role of the site of origin on the growth pattern and clinical features of recurrent craniopharyngiomas. METHODS The authors performed a retrospective analysis of 52 patients who had undergone uniform treatment by a single surgeon. For each patient, data concerning symptoms and signs, imaging features, hypothalamic-pituitary function, and recurrence-free survival rate were collected. RESULTS For children, delayed puberty was more frequent in the group with Type I (infradiaphragmatic) craniopharyngioma than in the group with Type TS (tuberoinfundibular and suprasellar extraventricular) lesions (p < 0.05). For adults, blindness was more frequent in the Type I group than in the Type TS group (p < 0.05). Nausea or vomiting, delayed puberty, and growth retardation were more frequent in children than in adults (p < 0.05). Overall clinical outcome was good in 48.07% of the patients and poor in 51.92%. Patients with Type TS recurrent tumors had significantly worse functional outcomes and hypothalamic function than patients with the Type I recurrent tumors but better pituitary function especially in children. CONCLUSIONS The origin of recurrent craniopharyngiomas significantly affected the symptoms, signs, functional outcomes, and hypothalamic-pituitary functions of patients undergoing repeated surgery. Differences in tumor growth patterns and site of origin should be considered when one is comparing outcomes and survival across treatment paradigms in patients with recurrent craniopharyngiomas.

Growth and weight of children with craniopharyngiomas based on the tumour location and growth pattern

This study aimed to characterise the weight and growth of children with craniopharyngiomas and to analyse the role of the tumour location and growth pattern in the development of obesity and growth retardation in these children. We retrospectively analysed the records of 109 consecutive children with primary craniopharyngiomas. The patients were divided into two subgroups according to the location of the tumour: intrasellar (Group A); and the floor of the third ventricle (Group B). Height and body mass index were measured at standardised ages and at time points before, after, and at the time of diagnosis. Endocrinological and hypothalamic measurements before and after surgery were compared. Reduced growth rates occurred in early infancy and persisted until diagnosis in Group A, but were only present from age 5-6 in Group B. Therefore, reduced growth rates occur early in the history of intrasellar tumours, whereas rapid postoperative weight gain invariably occurs in patients with third ventricle tumours, which is a significant predictive factor for severe long term obesity in patients with childhood craniopharyngiomas.

Arachnoid membranes in the posterior half of the incisural space: an inverted Liliequist membrane-like arachnoid complex.

OBJECT The aim of this study was to describe the similarity of configuration between the arachnoid complex in the posterior half of the incisural space and the Liliequist membrane. METHODS Microsurgical dissection and anatomical observation were performed in 20 formalin-fixed adult cadaver heads. The origin, distribution, and configuration of the arachnoid membranes and their relationships with the vascular structures in the posterior half of the incisural space were examined. RESULTS The posterior perimesencephalic membrane and the cerebellar precentral membrane have a common origin at the tentorial edge and form an arachnoid complex strikingly resembling an inverted Liliequist membrane. Asymmetry between sides is not uncommon. If the cerebellar precentral membrane is hypoplastic on one side or both, the well-developed quadrigeminal membrane plays a prominent part in partitioning the subarachnoid space in the posterior half of the incisural space. CONCLUSIONS The arachnoid complex in the posterior half of the incisural space can be regarded as an inverted Liliequist membrane. This concept can help neurosurgeons to gain better understanding of the surgical anatomy at the level of the tentorial incisura.

Secondary abscess arising in a craniopharyngioma

An abscess arising in a craniopharyngioma is rare, but has potentially high mortality and morbidity. Diagnosis is difficult because clinical and neuroradiological characteristics are not clearly defined. We report a patient with a pituitary abscess concomitant with a craniopharyngioma and discuss the pathophysiological mechanism. We discuss the previous five reports and suggest that abscesses with craniopharyngioma remain challenging clinical entities. We speculate that inflammation is a response to components of the ruptured epithelium of the cyst, thereby providing an explanation of the mechanism of abscess formation.