Customized ventral bony and dural opening in the transplanum/transtuberculum and transclival variants of extended endoscopic endonasal approach to suprasellar craniopharyngiomas: an approach-based stepwise cadaveric dissection and clinical applicability

BACKGROUND

Optimal initial exposure through an extended endoscopic endonasal approach (EEA) for suprasellar craniopharyngiomas ensures safe and unrestricted surgical access while avoiding overexposure, which may prolong the procedure and increase neurovascular adverse events.

METHOD

Here, the authors outline the surgical nuances of a customized bony and dural opening through the transplanum/transtuberculum and transclival variants of the extended EEA to suprasellar craniopharyngiomas based on the tumor-pituitary stalk relationship. A stepwise cadaveric dissection and intraoperative photographs relevant to the approaches are also provided.

CONCLUSION

Safe maximal resection of suprasellar craniopharyngiomas through extended EEAs can be feasibly and safely achieved by implementing of tailored ventral exposure.

A procedure in mice to obtain intact pituitary-infundibulum-hypothalamus preparations: a method to evaluate the reconstruction of hypothalamohypophyseal system

PURPOSE

The histopathological study of brain tissue is a common method in neuroscience. However, efficient procedures to preserve the intact hypothalamic-pituitary brain specimens are not available in mice for histopathological study.

METHOD

We describe a detailed procedure for obtaining mouse brain with pituitary-hypothalamus continuity. Unlike the traditional methods, we collect the brain via a ventral approach. We cut the intraoccipital synchondrosis, transection the endocranium of pituitary, broke the spheno-occipital synchondrosis, expose the posterior edge of pituitary, separate the trigeminal nerve, then the intact pituitary gland was preserved.

RESULT

We report an more effective and practical method to obtain continuous hypothalamus -pituitary preparations based on the preserve of leptomeninges.

COMPARED WITH THE EXISTING METHODS

Our procedure effectively protects the integrity of the fragile infundibulum preventing the pituitary from separating from the hypothalamus. This procedure is more convenient and efficient.

CONCLUSION

We present a convenient and practical procedure to obtain intact hypothalamic-pituitary brain specimens for subsequent histopathological evaluation in mice.

The importance of preserving the superior hypophyseal artery infundibular branch in craniopharyngioma surgery

PURPOSE

Postoperative pituitary dysfunction, a critical problem in the treatment of craniopharyngiomas, can occur even when the pituitary stalk is preserved. We hypothesized that compromise of the primary superior hypophyseal artery (pSHA) might be related to this occurrence.

METHODS

We performed a retrospective review of 131 patients with craniopharyngioma who underwent surgery from April 2009 to September 2021. The inclusion criteria were initial surgery, endoscopic transsphenoidal surgery, preoperative normal pituitary function or pituitary dysfunction in one axis, and morphological preservation of the pituitary stalk. The branches of the pSHA consist mainly of the chiasmatic branches (Cb), infundibular branches (Ib), and descending branches (Db). We analyzed the association between postoperative pituitary function and preservation of these branches.

RESULTS

Twenty patients met the criteria. Preoperative anterior pituitary function was normal in 18 patients, and there was isolated growth hormone deficiency in two patients. No patient had preoperative diabetes insipidus (DI). Anterior pituitary function was unchanged postoperatively in eight patients. Of these eight patients, bilateral preservation of pSHA Ib was confirmed in seven patients. Bilateral preservation of pSHA Ib was the only factor associated with preserved anterior pituitary function (p < 0.01). Fifteen patients were free of permanent DI, and the preservation of any given pSHA branch produced no significant difference in the postoperative occurrence of permanent DI.

CONCLUSIONS

Our study shows that bilateral preservation of pSHA Ib provides favorable postoperative anterior pituitary function in craniopharyngioma surgery; however, such preservation may have little effect on the postoperative occurrence of DI.

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.

The Difference Between Preoperative and Postoperative Pituitary Stalk Deviation Angles Can Predict Delayed Hyponatremia After Transsphenoidal Surgery

OBJECTIVE

Our aim was to assess the factors influencing the development of delayed hyponatremia after transsphenoidal surgery (TSS) for pituitary adenomas and analyze the effect of the difference between preoperative and postoperative pituitary stalk deviation angles on delayed hyponatremia.

METHODS

A retrospective study was performed on the clinical data of patients with pituitary adenomas who were treated with TSS at a single institution. On the basis of the observation of indicators such as pituitary stalk deviation angle and length of "measurable pituitary stalk" on magnetic resonance imaging, we determined the predictors of postoperative delayed hyponatremia through univariate and multivariate analyses.

RESULTS

Microscopic TSS was performed in 422 patients with pituitary adenoma, of whom 66 experienced postoperative delayed hyponatremia. Logistic regression analysis showed that the risk of delayed hyponatremia was greater for patients with a large difference between preoperative and postoperative pituitary stalk deviation angle (odds ratio = 1.040, 95% confidence interval: 1.018-1.051; P < 0.001) and a large difference in the "measurable pituitary stalk" (odds ratio = 1.128, 95% confidence interval: 1.011-1.258; P = 0.032), and patients with high blood sodium on the second day after surgery have a lower probability of developing delayed hyponatremia.

CONCLUSIONS

This study is the first to suggest the important role of the difference between preoperative and postoperative pituitary stalk deviation angles in predicting the development of delayed hyponatremia after TSS for pituitary adenomas.

Petrosal Approach for Giant Retrochiasmatic Craniopharyngioma: 2-Dimensional Operative Video

Microsurgical resection of craniopharyngiomas poses significant challenges, which are amplified with tumors in the retrochiasmatic location and larger size. Traditional pterional trans-sylvian, subfrontal translamia terminalis, or interhemispheric approaches provide narrow surgical corridors with obstructed visualization of the tumor by the prefixed chiasm and slit optic carotid window.1-5 The superior extension of the tumor compressing the hypothalamus and third ventricle are likewise inaccessible. Dissection through these approaches requires crossing and manipulation of the already compromised optic apparatus with surgical instruments. Finally, the basilar artery and its perforating branches are often adherent to the posterior aspect of the tumor, and are invisible. Endonasal endoscopic techniques have been utilized as a surgical approach that accesses the tumor without crossing the optic apparatus; however, these approaches have a significant risk of cerebrospinal fluid leakage and require dissection of the basilar artery and hypothalamus from long distances with lengthy instruments.6-9 Frequently, the surgeon achieves only partial removal. The petrosal approach is ideal for tumors in the retrochiasmatic location.10-13 Advantages include unhindered access to the retrochiasmatic space without crossing the optic nerve and chiasm. The angle of approach allows visualization superiorly to the hypothalamus. Additionally, the approach shortens the distance to the tumor, allowing for delicate bimanual dissection of the tumor, especially at the basilar artery and hypothalamic interfaces. This video demonstrates three cases of retrochiasmatic craniopharyngioma resection through the petrosal approach, highlighting these advantages to optimize patient outcome. The patients and guardians consented for the surgery, photography, and publication of the patient's image. Figures from Al-Mefty et al11 used with permission from the Journal of Neurosurgery Publishing Group. Additional figures republished from Al-Mefty et al.12 "The petrosal approach for the resection of retrochiasmatic craniopharyngiomas," Neurosurgery, 2008, volume 62, issue 5 Suppl 2 (ONS), ONS331-ONS336, by permission of the Congress of Neurological Surgeons.

3D fat-suppressed T1-weighted volume isotropic turbo spin-echo acquisition (VISTA) imaging for the evaluation of the ectopic posterior pituitary gland

OBJECTIVE

We evaluated the usefulness of fat-suppressed three-dimensional T1-weighted volume isotropic turbo spin-echo acquisition (FS 3D T1W-VISTA) imaging for the evaluation of the ectopic posterior pituitary gland (EPPG).

MATERIALS AND METHODS

This retrospective study included 9 patients with EPPG due to causes other than tumor. All underwent sagittal two-dimensional (2D) T1W-, FS 3D T1W-VISTA- (VISTA), and 3D T2W-driven equilibrium radiofrequency reset pulse (DRIVE) imaging. Two radiologists independently reviewed the 2D T1W- and VISTA images for their image quality and for visualization of the EPPG and of pituitary stalk transection. DRIVE findings were used as the reference standard for pituitary stalk transection. Interobserver and intermodality agreements were evaluated with the kappa (κ) coefficient. The mean grade assigned to the 2D T1W- and the VISTA imaging technique for visualization of the EPPG was assessed by the Mann-Whitney U test.

RESULTS

Interobserver agreement for visualization of the EPPG on 2D T1W- and VISTA images was excellent (κ = 0.82 and κ = 1.00, respectively). The mean grade for EPPG visualization was significantly higher for VISTA- than 2D T1W images (p = 0.0039).

CONCLUSION

FS 3D T1W-VISTA imaging is useful for the evaluation of EPPG. Conventional MRI yields insufficient information for the evaluation of the ectopic posterior pituitary gland (EPPG). The visualization of the EPPG was significantly higher for fat-suppressed three-dimensional T1-weighted volume isotropic turbo spin-echo acquisition (FS 3D T1W-VISTA) than 2D T1W images. FS 3D T1W-VISTA imaging is useful for the evaluation of the EPPG.

Pituitary stalk gangliogliomas: Case report and literature review

INTRODUCTION

Gangliogliomas rarely occur in the sella or suprasellar region and are almost never seen in the pituitary stalk. Seven cases of gangliogliomas occurring in this region have been reported; only one case involved a tumor within the pituitary stalk. Of the six tumors external to the pituitary stalk, two occurred in the neurohypophysis, one was in the adenohypophysis, the location of one was unspecified, and two extensively invaded the optic chiasm, hypothalamus and brainstem. This is only the second reported case of a pituitary stalk ganglioglioma, and it is unique in its use of an extended endoscopic endonasal approach for biopsy.

CASE REPORT

A 51-year old woman presented with an eleven-month history of polydipsia and polyuria leading to the diagnosis of diabetes insipidus. Magnetic Resonance Imaging of the brain revealed contrast-enhanced thickening and anterior bowing of the hypophyseal stalk. An extended endoscopic endonasal approach permitted midline removal of the tuberculum sella, opening of underlying dura, and exposure of the pituitary stalk. A firm, white, 4 mm diameter mass, integral to the right side of the enlarged pituitary stalk was seen and biopsied. Histopathological analysis was consistent with WHO grade 1 ganglioglioma. The patient tolerated the procedure well and required no endocrinologic treatment other than desmopressin.

CONCLUSION

Pituitary stalk gangliogliomas are extremely rare. The diagnosis should be considered in patients with pituitary stalk enlargement. Endoscopic endonasal approach is a safe surgical approach to establish a tissue diagnosis which is essential for pathologic certainty given the wide differential diagnosis of stalk lesions.

Resection of an Isolated Pituitary Stalk Epidermoid Cyst Through a Pretemporal Approach: Case Report and Review of the Literature

BACKGROUND

Intracranial epidermoid cysts are congenital epidermal inclusion cysts derived from ectodermal origin with desquamated skin. The majority of these cysts occur in the cerebellopontine angle cistern. Epidermoid cyst of the pituitary stalk, however, is a rare location. To date, only 4 previous cases have been reported.

CASE DESCRIPTION

A 63-year-old male presented to our clinic with migraine headaches, dizziness, increased thirst, increased urinary frequency, and impotence. Magnetic resonance imaging of the brain demonstrated a rim-enhancing cystic mass with diffusion restriction on diffusion-weighted imaging located within the pituitary stalk. The patient underwent a pretemporal approach with gross total resection of the cyst. The patient's postoperative course was uneventful with no new deficits and/or endocrinopathies.

CONCLUSION

Epidermoid cyst of the pituitary stalk is an unusual and rare presentation. Four other cases treated via endoscopic approaches have been previously reported in the neurosurgical literature. To our knowledge this is the first case description of an infundibular epidermoid cyst pressing with isolated diabetes insipidus surgically treated via a transcranial pretemporal approach with gross total resection. The patient had a smooth and uneventful postoperative course with persistent diabetes insipidus.

Arterial Supply to the Pituitary Gland: A Comprehensive Review

Knowledge of the blood supply to the pituitary gland is important for clinicians and surgeons. Therefore, a good working knowledge of this anatomy is important. The goal of this article was to review current anatomic knowledge of the blood supply to the pituitary gland and its clinical relevance.

A retaining sphenoid and dura procedure in the rat to obtain intact pituitary-infundibulum-hypothalamus preparations

BACKGROUND

The histopathological study of brain tissue is a conventional method in neuroscience. However, procedures specifically developed to recover intact hypothalamic-pituitary brain specimens, are not available.

NEW METHOD

We describe a detailed protocol for obtaining intact rat brain with pituitary-hypothalamus continuity through an intact infundibulum. The brain is collected via a ventral approach through removing the skull base. Membranous structures surrounding the hypothalamus-pituitary system can be preserved, including vasculature.

RESULTS

We report a retaining sphenoid and dura technique to obtain intact hypothalamic-pituitary brain preparations, and we confirm the practicability of this method. By combination of this technique with histological analysis or 3D brain tissue clearing and imaging methods, the functional morphology structure of the hypothalamus-pituitary can be further explored.

COMPARISON WITH EXISTING METHOD

The current procedure is limited in showing the connection between the hypothalamus and the pituitary. Our procedure effectively protects the integrity of the fragile infundibulum and thus prevents the pituitary from separating from the hypothalamus.

CONCLUSIONS

We present a convenient and practical approach to obtain intact hypothalamus-pituitary brain specimens for subsequent histopathological evaluation.

Near-Infrared Fluorescence with Second-Window Indocyanine Green as an Adjunct to Localize the Pituitary Stalk During Skull Base Surgery

A potential application of near-infrared (NIR) fluorescence imaging using second-window indocyanine green (SWIG) is demonstrated. We hypothesized that because the pituitary lacks a blood-brain barrier, we might visualize the pituitary stalk using SWIG. A 52-year-old, right-handed man presented to our clinic for evaluation of progressive loss of vision. Physical examination was significant for loss of right peripheral vision and near-complete loss of left field vision. Prolactin was high-normal at 16.2 mg/dL. Brain magnetic resonance imaging demonstrated a 36-mm sellar mass extending superiorly and laterally crossing the intracranial left internal carotid artery, consistent with a nonfunctional pituitary macroadenoma. We elected to pursue left pterional craniotomy for resection. The patient was eligible for our SWIG clinical trial and consented to the study. SWIG is a novel, investigational technique using Food and Drug Administration-approved indocyanine green to enhance visualization of neoplastic tissue intraoperatively.^1-7 The patient received 2.5 mg/kg of indocyanine green intravenously approximately 24 hours preoperatively. Intraoperatively, under white-light microscopy, the tumor was easily identified and distinguished from the optic nerves and internal carotid artery. After debulking of the gross tumor, NIR visualization using a laser-equipped endoscope⁸ demonstrated strong NIR fluorescence in the pituitary stalk. Despite the distorted anatomy, this technique enabled us to confidently identify and preserve the pituitary stalk. Postoperatively, the patient had persistently high urine output that normalized in 24 hours without desmopressin (sodium 139-140 mmol/L); after uneventful recovery, he was discharged with mild improvement in visual function. This case demonstrated a potential use of our SWIG protocol. As the stalk demonstrates strong NIR fluorescence after high-dose indocyanine green administration, surgeons may be able to better localize and preserve the stalk even in complex skull base tumor cases where the anatomy may be significantly distorted.

Age related signal changes of the pituitary stalk on thin-slice magnetic resonance imaging in infants

PURPOSE

Signals of some brain regions change along with development in T1-weighted imaging (T1WI) in infants. This study aimed to assess the association of the signal intensity of the pituitary stalk on thin-slice T1WI with infant age.

METHODS

This retrospective study was performed in 89 infants (gestational age [GA], 25-41 weeks; postmenstrual age [PMA], 36-46 weeks; chronological age [CA], 4-141 days) without intracranial abnormalities. The signal ratio of the pituitary stalk/pons on thin-slice T1WI was calculated, and its correlations with GA, PMA, and CA were assessed. Additionally, the signal ratio of the anterior pituitary gland/pons was calculated, and its correlation with that of the pituitary stalk was assessed. The signal intensity and distribution of the pituitary stalk were visually rated, and their correlations with GA, PMA, and CA were assessed.

RESULTS

The signal ratio of the pituitary stalk was significantly positively correlated with GA (P < 0.001) and negatively correlated with CA (P < 0.001), but was not correlated with PMA. Stepwise multiple regression revealed that CA was independently associated with the signal ratio of the pituitary stalk (P < 0.001). GA was significantly higher (P < 0.05) and CA was significantly lower (P < 0.05) in infants with a high signal intensity and wide distribution of high signal intensity of the pituitary stalk.

CONCLUSIONS

The signal intensity of the pituitary stalk on T1WI was negatively correlated with CA in infants, which might be related to postnatal changes in the pars tuberalis of the pituitary stalk after birth in infants.

Neuro-radiological features can predict hypopituitarism in primary autoimmune hypophysitis

Primary autoimmune hypophysitis (PAH) is considered an underdiagnosed disease, due to the difficulty in reaching a definitive diagnosis. PAH clinical diagnosis remains an exclusion diagnosis. We aimed to correlate PAH neuro-radiological signs to endocrine features and evaluate their prognostic role. 24 PAH cases were enrolled and classified according to neuro-radiological signs: in 12 adeno-hypophysitis (AHs), 8 infundibulo-neuro-hypophysitis (INHs) and 4 pan-hypophysitis (PHs). Secondary hypogonadism developed more frequently in INHs as compared to AHs (54.5% vs. 27.3%, p = 0.05), without no difference with PHs (p = 0.6). Diabetes insipidus occurred more frequently in INHs cases (72.7%, p < 0.001) and in PHs cases (27.3%, p = 0.007), as compared to AHs cases (0%). Similarly, all cases of GHD occurred in INHs (100%) as compared to AHs (0%, p < 0.001) and PHs (0%, p < 0.001). The pituitary stalk (PS) showed a pseudo-triangular shape (larger at the optical chiasma) in INHs and a pseudo-cylindrical shape (larger both at the optical chiasma and at the pituitary insertion) in PHs. The PS pseudo-triangular shape correlated to the occurrence of GHD and diabetes insipidus (p < 0.001/p = 0.03). At the 1-year follow-up, improvement of baseline radiological features positively correlated with the loss of the neuro-pituitary "bright spot" on T1-weighted images (OR 0.16; 95% CI 0.03-0.9 p = 0.02) and with a PS diameter at the optical chiasma level larger than 4.1 mm (AUC 0.97, sensibility 80%, specificity 100%, OR 6; 95% CI1.1-28.8, p = 0.01) Our data suggest that neuro-radiological PAH classification in PH, AH and INH can predict pituitary dysfunction and that some neuro-radiological features, such as the pituitary stalk diameter and the loss of the neuro-pituitary bright spot on T1w images can play a role as a positive prognostic marker of the radiological hypophysitis outcome.

[Thickening of the pituitary stalk in children and adolescents with central diabetes insipidus: Causes and consequences]

BACKGROUND

Central diabetes insipidus (CDI) is a rare disorder in children. The aetiology of CDI in childhood is heterogeneous. The aim of this study is to illustrate the importance of a careful clinical and neuro-radiological follow-up of the pituitary and hypothalamus region in order to identify the aetiology and the development of associated hormonal deficiencies.

METHODS

Clinical and auxological variables of 15 children diagnosed with CDI were retrospectively analysed in a paediatric hospital. Evaluations of adenohypophyseal function and cranial MRI were performed periodically.

RESULTS

The mean age at diagnosis of CDI was 9.6 years (range: 1.32-15.9). The aetiological diagnosis could be established initially in 9 of the 15 patients, as 7 with a germinoma and 2 with a histiocytosis. After a mean follow-up of 5.5 years (range: 1.6-11.8), the number of idiopathic cases was reduced by half. At the end of the follow-up, the aetiological diagnoses were: 9 germinoma (60%), 3 histiocytosis (20%), and 3 idiopathic CDI (20%). There is a statistically significant association between stalk thickening and tumour aetiology. At least one adenohypophyseal hormonal deficiency was found in 67% of cases, with the majority developing in the first two years of follow-up. Growth hormone deficiency (60%) was the most prevalent.

CONCLUSION

The follow-up of CDI should include hormone evaluation with special attention, due to its frequency, to GH deficiency. In addition, a biannual MRI in an idiopathic CDI should be performed, at least during the first 2-3 years after diagnosis, as 50% of them were diagnosed with a germinoma or histiocytosis during this period.

Surgical approach for suprasellar hemangioblastomas preserving the pituitary stalk: Review of the literature and report of a further case

Hemangioblastomas (HBLs) are challenging vascular tumours with rare suprasellar location Surgery is recommended in patients with visual impairment, endocrine disorders or hydrocephalus. Surgical removal of pituitary stalk HBLs is challenging due to their location and high vascularity. Our narrative review was guided by the question: "what is the more suitable surgical approach to excise a suprasellar HBL?". Pertinent English literature was scrutinized from database inception to October 2016. Eighteen articles matched our selection criteria. Among the surgically treated patients, 4 were treated through a trans-sphenoidal (TS) approach, 13 through a transcranial approach (2 of them after TS failure). Five other cases were treated with radiotherapy (adjuvant in 3 cases) and 9 patients were managed with simple observation and/or medical treatment. We add a case of complete suprasellar HBL resection through an orbito-zygomatic (OZ) craniotomy with extradural anterior clinoidectomy (EAC). To achieve satisfactory oncologic results with acceptable morbidity for symptomatic suprasellar HBLs, complete tumour removal with pituitary stalk sparing should be attempted through an OZ craniotomy with EAC that provides adequate exposure of the tumour, its vascular supply and the adjacent neural structures.

Congenital Hypopituitarism

Mutations of growth hormone genes and pituitary transcription factors account for a small proportion of cases of severe congenital hypopituitarism. Most cases show characteristic MRI findings of pituitary stalk interruption syndrome. Clinical suspicion should prompt assessment of cortisol, free T4, thyroid-stimulating hormone, and growth hormone levels together with MRI of the hypothalamic and pituitary regions.

Delayed Occurrence of Diabetes Insipidus After Transsphenoidal Surgery with Radiologic Evaluation of the Pituitary Stalk on Magnetic Resonance Imaging

BACKGROUND

Diabetes insipidus (DI) is a major complication of transsphenoidal surgery (TSS). DI usually occurs within a couple of days after TSS. Delayed occurrence of postoperative DI is rarely observed and its developing mechanisms remain unknown.

METHODS

Six patients were identified as having postoperative delayed DI, which was defined as DI that first occurred 2 or more weeks after TSS. They consisted of 1 male and 5 females, and their mean age was 38.3 years (range, 10-76 years). Five patients were histologically diagnosed with Rathke cleft cyst (RCC), and one had RCC coexisting with prolactin-secreting adenoma. Sequential T1-weighted magnetic resonance imaging was evaluated for hyperintensity (HI) in the pituitary stalk and the posterior lobe, indicating the location of antidiuretic hormone.

RESULTS

No patients had any DI before TSS. Delayed DI occurred 2 weeks to 3 months after TSS and persisted for 2 weeks to 5 months. T1-weighted magnetic resonance imaging showed that the HI in the posterior lobe became faint but did not disappear after DI occurrence, and their intensities increased with recovery from DI. In contrast, the HI in the pituitary stalk was found faintly preoperatively and turned clear postoperatively and decreased with recovery from DI. The morphologic patterns were dependent on DI duration.

CONCLUSIONS

In the delayed occurrence of DI, it was suggested that preoperative antidiuretic hormone transport was mildly congested yet not completely blocked when DI manifested postoperatively. Gradual spreading of inflammation to the infundibulum after RCC removal was considered as 1 possible mechanism of this delayed DI development.

High-resolution heavily T2-weighted magnetic resonance imaging for evaluation of the pituitary stalk in children with ectopic neurohypophysis

BACKGROUND

In anterior pituitary deficiency, patients with non visible pituitary stalk have more often multiple deficiencies and persistent deficiency than patients with visible pituitary stalk.

OBJECTIVE

To compare the diagnostic value of a high-resolution heavily T2-weighted sequence to 1.5-mm-thick unenhanced and contrast-enhanced sagittal T1-weighted sequences to assess the presence of the pituitary stalk in children with ectopic posterior pituitary gland.

MATERIALS AND METHODS

We retrospectively evaluated the MRI data of 14 children diagnosed with ectopic posterior pituitary gland between 2010 and 2014. We evaluated the presence of a pituitary stalk using a sagittal high-resolution heavily T2-weighted sequence and a 1.5-mm sagittal T1-weighted turbo spin-echo sequence before and after contrast medium administration.

RESULTS

A pituitary stalk was present on at least one of the sequences in 10 of the 14 children (71%). T2-weighted sequence depicted the pituitary stalk in all 10 children, whereas the 1.5-mm-thick T1-weighted sequence depicted 2/10 (20%) before contrast injection and 8/10 (80%) after contrast injection (P=0.007).

CONCLUSION

Compared with 1.5-mm-thick contrast-enhanced T1-weighted sequences, high-resolution heavily T2-weighted sequence demonstrates better sensitivity in detecting the pituitary stalk in children with ectopic posterior pituitary gland, suggesting that contrast injection is unnecessary to assess the presence of a pituitary stalk in this setting.

Spontaneous intermittent MRI changes of a pituitary stalk lesion causing diabetes insipidus and amenorrhea

Lymphocytic infundibulo-neurohypophysitis is a rare disorder. We report the case of a 29 year-old woman with diabetes insipidus and amenorrhea, in whom the magnetic resonance imaging demonstration of a pituitary stalk lesion was intermittent. We suggest that, in patients with endocrine dysfunction and positivity of circulating antipituitary antibodies at high title, magnetic resonance imaging should be repeated after few months, if negative.

Prediction of postoperative diabetes insipidus using morphological hyperintensity patterns in the pituitary stalk on magnetic resonance imaging after transsphenoidal surgery for sellar tumors

PURPOSE

Diabetes insipidus (DI) remains a complication of transsphenoidal surgery (TSS) for sellar and parasellar tumors. Antidiuretic hormone (ADH) appears as hyper intensity (HI) in the pituitary stalk and the posterior lobe of the pituitary gland on T1-weighted magnetic resonance (MR) imaging. Its disappearance from the posterior lobe occurs with DI, indicating a lack of ADH. The appearance of HI in the pituitary stalk indicates disturbances in ADH transport.

METHODS

This retrospective study included 172 patients undergoing TSS for sellar tumors at our institute from 2006 to 2014. Sequential T1-weighted MR images without enhancement were evaluated for HI in the pituitary stalk and the posterior lobe to assess the localization of ADH before and at intervals after TSS. DI was assessed pre- and postoperatively. HI in the pituitary stalk showed the following morphology: (1) ovoid in the distal end of the pituitary stalk (group A), (2) linear in the distal part of the pituitary stalk (group B), (3) linear in the whole pituitary stalk (group C).

RESULTS

Preoperative DI occurred in 6 patients (3.5 %) with no HI observed in the posterior lobe. Postoperative DI was transient in 82 patients (47.7 %), and permanent in 11 (6.4 %). One week after surgery, HI was absent in the posterior lobe in 74 patients (43.0 %), and present in the pituitary stalk in 99 patients (57.6 %); both were significantly correlated with postoperative DI (p < 0.001). The absence of HI in the posterior lobe (A, 48.9 %; B, 68.3 %; C, 92.3 %), persistence of DI (A, 3.7 days; B, 45.9 days; C, 20.5 months), and duration until HI recovery in the posterior lobe (A, 3.6 months; B, 6.8 months; C, 22.9 months) were greatest in group C, followed by group B, and then group A. Fourteen group A patients did not have postoperative DI despite having HI in the pituitary stalk and the posterior lobe. Four group C patients developed permanent DI with persistence HI in the pituitary stalk.

CONCLUSION

HI in the pituitary stalk and its absence in the posterior lobe indicated postoperative DI, which was transient if HI was detected in the pituitary stalk. DI duration could be predicted by the length of HI in the pituitary stalk, which corresponded to the degree of ADH transport obstruction.

Radiosurgery for infundibulum adenoma: stalk dose implications

Treating pituitary adenomas in the infundibulum with stereotactic radiosurgery (SRS), achieving tumor volume control while preserving pituitary endocrine function and visual function, is challenging. We present a case of a recurrent remnant infundibular lesion treated with Gamma Knife surgery (GKS). The mass was treated with microsurgical resection twice, and the residual stalk lesion was treated with single-session SRS employing a margin dose of 15 Gy to the infundibulum. Five years after GKS, tumor regression persists without visual dysfunction or hypopituitarism. Radiosurgical doses of 30 Gy to the pituitary stalk may be tolerated by patients while maintaining endocrine function.

Pituitary tuberculoma: A consideration in the differential diagnosis in a patient manifesting with pituitary apoplexy-like syndrome

Pituitary tuberculoma is extremely rare, even in endemic regions of tuberculosis and much less frequently as a presentation of pituitary apoplexy. We describe a 25-year-old female presented with sudden onset of headache and vision loss of left eye which mimicking symptoms of pituitary apoplexy. MRI of the pituitary gland showed a rim-enhancing lesion at the intrasellar region extending into the suprasellar area, but absence of posterior bright spot with enhancement of the pituitary stalk. Pituitary hormonal evaluation revealed panhypopituitarism and diabetes insipidus. An urgent transphenoidal surgery of the pituitary gland was undertaken for which the histopathology showed necrotizing granulomatous inflammation with infarcted adjacent pituitary tissue. Despite negative fungal and AFB staining, pituitary tuberculoma was presumptively diagnosed based on imaging, pathology and the high incidence of tuberculosis in the country. After the course of anti-tuberculosis therapy, the clinical findings were dramatically improved, supporting the diagnosis. Pituitary tuberculoma is extremely rare in particular with an apoplexy-like presentation but should be one of the differential diagnosis list of intrasellar lesions in the patient presenting with sudden onset of headache and visual loss. The presence of diabetes insipidus and thickened with enhancement of pituitary stalk on MRI were very helpful in diagnosing pituitary tuberculosis.

Sporadic Hemangioblastoma in the Pituitary Stalk: A Case Report and Review of the Literature

Hemangioblastomas in the pituitary stalk are especially rare. Most pituitary stalk hemangioblastomas reported in the literature were associated with von Hippel-Lindau (VHL) disease. Here, we report only the 3rd case of sporadic pituitary stalk hemangioblastoma diagnosed in a 60-year-old woman. Despite the danger of potential complications due to excessive vascularity or proximity to important neural structures, the tumor in our case was successfully removed while preserving pituitary function. In this case, complete surgical excision was shown to be an effective treatment option for symptomatic pituitary stalk hemangioblastoma, and we suggest careful evaluation of any highly enhancing mass with a signal void in the pituitary stalk preoperatively, even if no VHL disease is evident.

Association of pituitary stalk management with endocrine outcomes and recurrence in microsurgery of craniopharyngiomas: A meta-analysis

OBJECTIVE

A craniopharyngioma (CP) is a benign tumor commonly considered to originate from the pituitary stalk. However, it is still controversial as to whether the pituitary stalk should be maintained after microsurgery to resect the tumor despite its own physiological function of the pituitary stalk. In this study, meta-analysis was conducted to evaluate the influence of the pituitary stalk resection on endocrine function and tumor recurrence rate.

METHODS

The relevant publications were identified by searching databases including Pubmed, Embase, Medline, and Web of Science. The extracted data were used as the basis for the meta-analysis by the RevMan 5.2 software program.

RESULTS

Seven articles were selected, including 420 clinical cases. The meta-analysis showed that retaining the pituitary stalk might reduce the occurrence rate of diabetes insipidus (OR=0.21, 95%CI=0.10, 0.46, P=0.0001) and the risk of potential impairment of anterior pituitary function (OR=0.04, 95%CI=0.01, 0.13, P<0.0001). However, there was no significant relationship between craniopharyngioma recurrence and pituitary stalk treatment (i.e., preservation or resection) (OR=1.40, 95%CI=0.59, 3.34, P=0.45).

CONCLUSION

The maintenance of the pituitary stalk may reduce the alterations in endocrine function and the occurrence of diabetes insipidus. However, it is not likely to enhance the recurrence rate of craniopharyngiomas.

Neurocysticercosis involving the pituitary stalk : case report and literature review

Neurocysticercosis (NCC) is the most common parasitic infestation of the central nervous system. Most cases of NCC are to related and/or associated with inflammation within the cerebral parenchyma. A 71-year-old woman presented with a 4-year history of visual disturbance. This symptom had become aggravated 4 weeks earlier. Her visual acuity gradually decreased and superior hemianopsia was noted. Magnetic resonance imaging (MRI) revealed an enhanced and thickened pituitary stalk accompanying a suspicious mass. The provisional diagnoses were lymphoma, glioma, or other inflammatory conditions. Laboratory studies, including blood and hormonal studies, showed normal findings. Surgical resection was performed. In the pathological examination, degenerated parasitic wall structure was seen and its contents were composed of completely degenerated focal globular structures suggesting the scolex of cysticercus. We report an unusual case of NCC involving the pituitary stalk which was presented with a juxtasellar tumor. The possible underlying mechanisms are discussed with a review of pertinent literature.

Characterization of the anatomic location of the pituitary stalk and its relationship to the dorsum sellae, tuberculum sellae and chiasmatic cistern

OBJECTIVE

The normal anatomic relationships characteristic of the pituitary stalk area were previously thought to involve only one location. The purpose of this study was to re-evaluate the anatomic location of the pituitary stalk and possible varying locations in relation to the tuberculum sellae and dorsum sellae using morphometric evaluation and anatomic dissection of human cadaveric specimens. The surgical implications of the variations are discussed.

METHODS

The calvaria were removed via routine autopsy dissections, and the brains were removed from the skull while preserving the pituitary stalk. The diaphragma sellae, tuberculum sellae, and the location of the pituitary stalk were examined in 60 human cadaveric heads obtained from fresh adult cadavers. Empty sellae were excluded.

RESULTS

The openings of the diaphragma sellae averaged 6.62 +/- 1.606 mm (range, 3-9 mm). The distance between the tuberculum sellae and the posterior part of the pituitary stalk was 1 to 8 mm. The upper face of the diaphragma sellae appeared flat in 26 (43%), concave in 24 (40%), and convex in 6 cases (10%), with a prominent tuberculum sellae in 4 cases (7%). The location of the chiasm was normal in 47 cases (78%), with a prefixed chiasm in 3 cases (5%) and a postfixed chiasm (17%) in the 10 cases. Four cadaver specimens had prominent tuberculum sellae and other parameters were not evaluated.

CONCLUSION

When opening the chiasmatic cistern, neurosurgeons should be aware about the relationship between the pituitary stalk and the surrounding structures to prevent inadvertent injury to the pituitary stalk.