Clinical presentation and surgical outcomes of very large and giant pituitary adenomas: 80 cases in a cohort study of 306 patients with pituitary adenomas.

PURPOSE: To identify differences in the presentation and surgical outcomes between very large (30-39 mm) and giant (≥ 40 mm) (LARGE group) pituitary adenomas (PAs) compared to the smaller group (< 30 mm) (non-LARGE group). METHODS: Eighty patients with very large (n = 44) or giant (n = 36) PAs and 226 patients in the non-LARGE group who underwent tumor resection by pituitary surgery between 2008 and 2023 were studied. Hormonal, radiological, ophthalmological, and pathological data, and surgical outcomes were evaluated. RESULTS: Preoperatively, patients of the LARGE group presented more frequently with visual impairment (82.5% vs. 22.1%, P < 0.001) and with pituitary apoplexy (15.0% vs. 2.7%, P < 0.001) than the non-LARGE group. Moreover, the LARGE group were more commonly associated with preoperative panhypopituitarism (28.8% vs. 6.2%, P < 0.001). This group presented cavernous sinus invasion more frequently (71.3% vs. 23.9%, P < 0.001). The non-LARGE group achieved surgical cure more often than the LARGE group (79.7% vs. 50.0%, P < 0.001), and the rate of major complications was higher in the latest (8.8% vs. 1.3%, P < 0.004). CONCLUSIONS: PAs ≥ 30 mm are most frequently accompanied by hormonal dysfunction, cavernous sinus invasion, and visual impairment. All this implies lower resection rates and higher postoperative complications than the smaller adenomas, posing a real surgical challenge.

Ultrasonographic Detective Flow Imaging for Evaluating Parathyroid Adenoma in Patients with Primary Hyperparathyroidism.

BACKGROUND: Detective flow imaging (DFI) is a new imaging technology that displays low-velocity blood flow, which is difficult to visualize on conventional color Doppler ultrasonography (CDU). In this study, we compared the usefulness of DFI with that of CDU and methoxy-isobutyl-isonitrile (MIBI) scintigraphy for detecting parathyroid adenoma (PA) in patients with primary hyperparathyroidism (PHPT). METHODS: From March 2021 to March 2023, 87 PHPT patients underwent surgery, and 66 had a single PA. We performed preoperative conventional ultrasonography with CDU, MIBI scintigraphy, and DFI for 42 patients (5 males and 37 females; mean age: 61.6 ± 15.4 years). RESULTS: MIBI scintigraphy detected PA in 85.7% (36/42) patients, and both CDU and DFI detected PA in all patients. The rates of vascularity in PA detected by CDU and DFI were 71.4% (30/42) and 85.7% (36/42), respectively. Vascularity was detected by DFI in 6 patients who were negative for vascularity on MIBI scintigraphy. Furthermore, DFI detected blood supply in 6 of the 12 patients with undetectable blood supply on CDU. Fisher's exact test revealed that high or low blood flow, as determined by DFI, was significantly associated with detection of feeding vessels in PA by CDU (P < 0.001). CONCLUSIONS: DFI was useful for preoperative detection of PA blood flow.

[Intraductal radiofrequency ablation under endosonography and cholangioscopy for residual adenoma of the major duodenal papilla with intraductal component]. / Vnutriprotokovaya radiochastotnaya ablyatsiya pod kontrolem endosonografii i kholangioskopii pri rezidual'noi adenome bol'shogo sosochka dvenadtsatiperstnoi kishki s vnutriprotokovym komponentom. Obzor literatury.

All adenomas of the major duodenal papilla (MDP) require resection regardless of morphological structure due to high risk of malignancy. Currently, intraluminal endoscopic interventions are preferable for these adenomas. MDP neoplasms with intraductal spread (type III and IV) are of particular difficulty for endoscopic techniques. Intraductal radiofrequency ablation provides new opportunities for minimally invasive treatment of patients with MDP adenomas and intraductal component. A 72-year-old patient after previous endoscopic papillectomy for MDP adenoma admitted to the Vishnevsky National Research Medical Center of Surgery due to residual adenomatous growths within the papillectomy zone extending to the common bile duct throughout 13 mm. The patient underwent intraductal RFA under endosonography and cholangioscopy. Despite difficult localization of residual growths extending to the common bile duct, endosonography-guided intraductal RFA provided total destruction of residual tumor that was confirmed by cholangioscopy. Length of treatment was 4 months, relapse-free period - 10 months. Minimally invasive endoscopic technology for residual MDP adenoma provided good clinical results.

Magnetic Resonance Imaging Features of the Sphenoid Sinus in Patients with Non-Functioning Pituitary Adenoma.

Background and Objectives: A magnetic resonance imaging (MRI) scan is part of the diagnostic protocol in pituitary adenoma patients. The goal of the present study is to present and analyse the MRI appearances of the sphenoid sinus (SS) in patients with non-functioning pituitary adenoma (NFPA). Materials and Methods: This is a retrospective case-control study conducted between January 2015 and December 2023 in a tertiary referral hospital. Forty NFPA patients were included in the study group, while the control group consisted of 30 age- and gender-matched cases. Results: The sellar type of SS pneumatization was the most frequently encountered pattern among both groups. The presence of the lateral recess of the SS, mucosal cysts, and sphenoethmoidal cells was similar in both patient groups. The proportion of patients with SS mucosal thickness greater than 3 mm was 42.5% in NFPA group and 3% in the control group, and this difference was statistically significant (p < 0.001). The space between the two optic nerves was significantly larger in the NFPA group as compared to the control group (p < 0.001). Conclusions: Our study was able to establish a statistically significant association between the presence of NFPA and both the thickening of the SS mucosa and increased space between optic nerves.

Incidentally detected follicular thyroid carcinoma mimicking parathyroid adenoma on Tc-99m MIBI scan: A case report.

RATIONALE: Primary hyperparathyroidism, though relatively prevalent among endocrine disorders, affecting 1% of the general population, often presents diagnostic challenges. Given its potential to precipitate severe complications including nephrolithiasis and fractures, timely diagnosis, and effective management are crucial. PATIENT CONCERNS: A 38-year-old woman with hypercalcemia was referred to the Department of Nuclear Medicine for a Tc-99m MIBI scan. DIAGNOSES: Tc-99m MIBI scan showed focal increased uptake in the left thyroid gland area, initially suggesting a parathyroid adenoma. Further examination using SPECT/CT revealed a nodular lesion within the left thyroid gland showing high Tc-99m MIBI uptake. INTERVENTIONS: Left thyroid lumpectomy confirmed the lesion as follicular thyroid carcinoma. On the second Tc-99m MIBI scan conducted after total thyroidectomy, a parathyroid adenoma was eventually detected in the right lower area, enabling the subsequent appropriate treatment, a right lower parathyroidectomy. OUTCOMES: Thirteen days after the parathyroidectomy, serum levels of total calcium and parathyroid hormone returned to normal. Furthermore, bone mineral density evaluated using DEXA remained within the expected range for her age even after 14 months. LESSONS: When interpreting the Tc-99m MIBI scan, it is essential to keep in mind that various tumors rich in mitochondria, such as thyroid carcinoma, could show a high uptake of Tc-99m MIBI.

Topic highlight on texture and color enhancement imaging in gastrointestinal diseases.

Olympus Corporation developed texture and color enhancement imaging (TXI) as a novel image-enhancing endoscopic technique. This topic highlights a series of hot-topic articles that investigated the efficacy of TXI for gastrointestinal disease identification in the clinical setting. A randomized controlled trial demonstrated improvements in the colorectal adenoma detection rate (ADR) and the mean number of adenomas per procedure (MAP) of TXI compared with those of white-light imaging (WLI) observation (58.7% vs 42.7%, adjusted relative risk 1.35, 95%CI: 1.17-1.56; 1.36 vs 0.89, adjusted incident risk ratio 1.48, 95%CI: 1.22-1.80, respectively). A cross-over study also showed that the colorectal MAP and ADR in TXI were higher than those in WLI (1.5 vs 1.0, adjusted odds ratio 1.4, 95%CI: 1.2-1.6; 58.2% vs 46.8%, 1.5, 1.0-2.3, respectively). A randomized controlled trial demonstrated non-inferiority of TXI to narrow-band imaging in the colorectal mean number of adenomas and sessile serrated lesions per procedure (0.29 vs 0.30, difference for non-inferiority -0.01, 95%CI: -0.10 to 0.08). A cohort study found that scoring for ulcerative colitis severity using TXI could predict relapse of ulcerative colitis. A cross-sectional study found that TXI improved the gastric cancer detection rate compared to WLI (0.71% vs 0.29%). A cross-sectional study revealed that the sensitivity and accuracy for active Helicobacter pylori gastritis in TXI were higher than those of WLI (69.2% vs 52.5% and 85.3% vs 78.7%, respectively). In conclusion, TXI can improve gastrointestinal lesion detection and qualitative diagnosis. Therefore, further studies on the efficacy of TXI in clinical practice are required.

A colonial serrated polyp classification model using white-light ordinary endoscopy images with an artificial intelligence model and TensorFlow chart.

In this study, we implemented a combination of data augmentation and artificial intelligence (AI) model-Convolutional Neural Network (CNN)-to help physicians classify colonic polyps into traditional adenoma (TA), sessile serrated adenoma (SSA), and hyperplastic polyp (HP). We collected ordinary endoscopy images under both white and NBI lights. Under white light, we collected 257 images of HP, 423 images of SSA, and 60 images of TA. Under NBI light, were collected 238 images of HP, 284 images of SSA, and 71 images of TA. We implemented the CNN-based artificial intelligence model, Inception V4, to build a classification model for the types of colon polyps. Our final AI classification model with data augmentation process is constructed only with white light images. Our classification prediction accuracy of colon polyp type is 94%, and the discriminability of the model (area under the curve) was 98%. Thus, we can conclude that our model can help physicians distinguish between TA, SSA, and HPs and correctly identify precancerous lesions such as TA and SSA.

Ectopic Pituitary Neuroendocrine Tumors/Adenomas Around the Sella Turcica

Functional or non-secretory ectopic pituitary neuroendocrine tumors (PitNET) can form around the sella turcica during the development of the adenohypophysis by differentiating and detaching from the pharyngeal roof. These tumors usually appear in the sphenoid sinus, clivus, cavernous sinus, infundibulum, and suprasellar cistern. Ectopic PitNETs typically display the characteristic magnetic resonance imaging findings of pituitary adenomas. However, preoperative diagnosis of PitNETs is usually challenging because of the variety of clinical and imaging presentations, locations, and sizes. Ectopic suprasellar PitNETs resemble mass lesions in the pituitary stalk. Ectopic cavernous sinus of PitNETs are typically microadenomas in the medial wall. Ectopic sphenoclival tumors are characterized by more aggressive tumor activity than the other ectopic PitNETs. Although ectopic PitNETs are exceedingly rare, they should be considered as a differential diagnosis for masses around the sella turcica. Treatment of the disease should be individualized and may include medical care, surgical resection, gamma-knife radiosurgery, and radiotherapy.

Diagnostic performance of hepatic CT and chemical-shift MRI to discriminate lipid-poor adrenal adenomas from hepatocellular carcinoma metastases.

PURPOSE: To evaluate the diagnostic performance of multiphase hepatic CT parameters (non-contrast attenuation, absolute and relative washout ratios [APW and RPW, respectively], and relative enhancement ratio [RER]) and chemical-shift MRI (CS-MRI) for discriminating lipid-poor adrenal adenomas (with non-contrast CT attenuation > 10 HU) from metastases in patients with hepatocellular carcinoma (HCC). METHODS: This retrospective study included HCC patients with lipid-poor adrenal lesions who underwent multiphase hepatic CT between January 2010 and December 2021. For each adrenal lesion, non-contrast attenuation, APW, RPW, RER, and signal-intensity index (SI-index) were measured. Each parameter was compared between adenomas and metastases. The area under the receiver operating characteristic curves (AUCs) and sensitivities to achieve 100% specificity for adenoma diagnoses were determined. RESULTS: 104 HCC patients (78 men; mean age, 71.8 ± 9.6 years) with 63 adenomas and 48 metastases were identified; CS-MRI was performed in 66 patients with 49 adenomas and 21 metastases within one year of CT. Lipid-poor adenomas showed lower non-contrast attenuation (22.9 ± 7.1 vs. 37.9 ± 9.4 HU) and higher APW (40.5% ± 12.8% vs. 23.7% ± 17.4%), RPW (30.0% ± 10.2% vs. 12.4% ± 9.6%), RER (329% ± 152% vs. 111% ± 43.0%), and SI-index (43.3 ± 20.7 vs. 10.8 ± 13.4) than HCC metastases (all p < .001). AUC for non-contrast attenuation, APW, RPW, RER, and SI-index were 0.894, 0.786, 0.904, 0.969, and 0.902, respectively. The sensitivities to achieve 100% specificity were 7.9%, 25.4%, 30.2%, 63.5%, and 24.5%, respectively. Combined RER and APW achieved the highest sensitivity of 73.0%. CONCLUSION: Multiphase hepatic CT allows for better discrimination between lipid-poor adrenal adenomas and metastases relative to CS-MRI, especially when combined with RER and washout parameters.

MRI 3D SPACE T2WI for Pituitary Adenoma Cavernous Sinus Invasion Diagnosis.

OBJECTIVE: This study aims to assess the utility of magnetic resonance imaging (MRI) 3D SPACE T2-weighted imaging (T2WI) sequences in evaluating cavernous sinus invasion by pituitary adenomas. METHODS: Data were collected from patients who underwent continuous pituitary MRIexaminations at the Medical Imaging Center of our hospital from October 2019 to February 2021. Eligible cases were evaluated for sagittal and axial T1WI sequences, coronal 3D SPACE T2WI sequences, and sagittal and coronal enhanced T1-weighted imaging (T1WI) sequences using the INFINITT PACS workstation. The Wilcoxon signed-rank test for paired samples and the Mann-Whitney U test for 2 independent samples were used to statistically analyze differences in image quality scores among various groups. In addition, the sensitivity, specificity, positive predictive value, and negative predictive value of each observation index were compared with intraoperative results. RESULTS: 3D SPACE T2WI showed superior cavernous sinus imaging quality compared with contrast enhanced T1WI and T2WI plain scans (P < 0.05). The sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 90.0%, 55.60%, and 100.0%, respectively. The accuracy for pituitary adenoma invasiveness diagnosis based on cavernous sinus medial wall integrity was 94.40%. CONCLUSIONS: The imaging quality of the medial wall of the cavernous sinus on the 3D SPACE T2WI plain scan sequence surpassed that of contrast enhanced T1WI TSE-enhanced scans and T2WI TSE plain scans. The continuous observation of the medial wall of the cavernous sinus using this sequence holds great diagnostic value for assessing cavernous sinus invasion by pituitary adenomas. This strategy is more reliable than traditional MRI observation indicators.

Real-world experience with 11C-methionine positron emission tomography in the management of acromegaly.

BACKGROUND: L-[methyl-11C]-methionine-positron emission tomography (Met-PET) is a potentially important imaging adjunct in the diagnostic workup of pituitary adenomas, including somatotroph tumors. Met-PET can identify residual or occult disease and make definitive therapies accessible to a subgroup of patients who would otherwise require lifelong medical therapy. However, existing data on its use are still limited to small case series. Here, we report the largest single-center experience (n = 61) in acromegaly. METHODS: A total of 189 cases of acromegaly were referred to our national Met-PET service in the last 12 years. For this analysis, we have reviewed outcomes in those 61 patients managed exclusively by our multidisciplinary team (single center, single surgeon). Referral indications were as follows: indeterminate magnetic resonance imaging (MRI; n = 38, 62.3%), occult residual (n = 14, 23.0%), (radio-)surgical planning (n = 6, 9.8%), and occult de novo tumor (n = 3, 4.9%). RESULTS: A total of 33/61 patients (54.1%) underwent PET-guided surgery. Twenty-four of 33 patients (72.7%) achieved complete biochemical remission following (re-)surgery. Insulin-like growth factor 1 levels were reduced to <2 × upper limit of normal (ULN) in 6 of the remaining 9 cases, 3 of whom achieved levels of <1.1 × ULN compared with mean preoperative levels of 2.4 × ULN (SD 0.8) for n = 9. Only 3 patients developed single new hormonal deficits (gonadotropic/thyrotropic insufficiency). There were no neurovascular complications after surgery. CONCLUSION: In patients with persistent/recurrent acromegaly or occult tumors, Met-PET can facilitate further targeted intervention (surgery/radiosurgery). This led to complete remission in most cases (24/33) or significant improvement with comparatively low risk of complications. L-[methyl-11C]-methionine-positron emission tomography should therefore be considered in all patients who are potential candidates for further surgical intervention but present no clear target on MRI.

Don't chase the adenoma: A probabilistic approach to imaging before parathyroidectomy.

BACKGROUND: Preoperative imaging before parathyroidectomy can localize adenomas and reduce unnecessary bilateral neck explorations. We hypothesized that (1) the utility of preoperative imaging varies substantially depending on the preoperative probability of having adenoma(s) and (2) that a selective imaging approach based on this probability could avoid unnecessary patient costs and radiation. METHODS: We analyzed 3,577 patients who underwent parathyroidectomy for primary hyperparathyroidism from 2001 to 2022. The predicted probability of patients having single or double adenoma versus hyperplasia was estimated using logistic regression. We then estimated the relationship between the predicted probability of single/double adenoma and the likelihood that sestamibi or 4-dimensional computed tomography was helpful for operative planning. Current Medicare costs and published data on radiation dosing were used to calculate costs and radiation exposure from non-helpful imaging. RESULTS: The mean age was 62 ± 13 years; 78% were women. Adenomas were associated with higher mean calcium (11.2 ± 0.74 mg/dL) and parathyroid hormone levels (140.6 ± 94 pg/mL) than hyperplasia (9.8 ± 0.52 mg/dL and 81.4 ± 66 pg/mL). The probability that imaging helped with operative planning increased from 12% to 65%, as the predicted probability of adenoma increased from 30% to 90%. For every 10,000 patients, a selective approach to imaging that considered the preoperative probability of having adenomas could save patients up to $3.4 million and >239,000 millisieverts of radiation. CONCLUSION: Rather than imaging all patients with primary hyperparathyroidism, a selective strategy that considers the probability of having adenomas could reduce costs and avoid excess radiation exposure.

Predictive value of cyst/tumor volume ratio of pituitary adenoma for tumor cell proliferation.

BACKGROUND: MRI has been widely used to predict the preoperative proliferative potential of pituitary adenoma (PA). However, the relationship between the cyst/tumor volume ratio (C/T ratio) and the proliferative potential of PA has not been reported. Herein, we determined the predictive value of the C/T ratio of PA for tumor cell proliferation. METHODS: The clinical data of 72 patients with PA and cystic change on MRI were retrospectively analyzed. PA volume, cyst volume, and C/T ratio were calculated. The corresponding intraoperative specimens were collected. Immunohistochemistry and hematoxylin-eosin staining were performed to evaluate the Ki67 index and nuclear atypia. Patients were categorized according to the Ki67 index (< 3% and ≥ 3%) and nuclear atypia (absence and presence). Univariate and multivariate analyses were used to identify the significant predictors of the Ki67 index and nuclear atypia. The receiver operating characteristic curve assessed the prediction ability of the significant predictors. RESULTS: Larger tumor volumes, smaller cyst volumes, and lower C/T ratios were found in patients with higher Ki67 indexes and those with nuclear atypia (P < 0.05). C/T ratio was an independent predictor of the Ki67 index (odds ratio = 0.010, 95% confidence interval = 0.000-0.462) and nuclear atypia (odds ratio = 0.010, 95% confidence interval = 0.000-0.250). The predictive value of the C/T ratio did not differ significantly from that of tumor volume (P > 0.05) but was better than that of cyst volume (P < 0.05). The area under the curve of the C/T ratio for predicting the Ki67 index and nuclear atypia was larger than that for predicting cyst volume and tumor volume. CONCLUSIONS: C/T ratios can be used to predict PA tumor proliferation preoperatively. Our findings may facilitate the selection of surgery timing and the efficacy evaluation of surgery.

The role of preoperative MRI in endoscopic transnasal transsphenoidal hypophysectomy of pituitary adenoma.

BACKGROUND: The trans-sphenoidal approach, commonly used for removing pituitary adenomas, has become a widely accepted and successful method. In recent years, the endoscopic trans-sphenoidal technique has emerged as a minimally invasive surgical approach for pituitary adenoma removal. The majority of pituitary adenomas exhibit a soft consistency and can be successfully extracted with aspiration and curettage using the trans-sphenoidal approach. However, a subset of around 5-15% of these adenomas possess a solid and fibrous texture. The occurrence of firm and fibrous adenomas is relatively common; unfortunately, there are no reliable predictors to identify them preoperatively. OBJECTIVES: The ability to forecast the reliability of magnetic resonance imaging (MRI) holds promise for improving prior preparation and impacts the extent of resection. DESIGN: A cross-sectional analysis of the investigation of magnetic resonance imaging (MRI) in relation to cancer histology was performed on 68 patients who had endoscopic trans-nasal excision for nonfunctional adenomas. MATERIALS AND METHODS: The determination of an intensity ratio was performed by employing quantitative estimates of MRI signal intensity obtained from both the adenoma and pons. During the surgical procedure, a series of sequential-graded procedures were used for the removal of tumours with varying consistencies. Softer tumours were addressed using the Suction technique (R1), while tumours of intermediate consistency were treated using curettes (R2). In order to evaluate the fibrotic content of firmer tumours, the utilization of Cavitron Ultrasound Surgical Aspirator (CUSA), and/or other micro-instruments (R3) was employed, with the histologic collagen fraction being quantified. In order to investigate and analyse the data, a statistical analysis was conducted. A predictive relationship between resection category and both intensity ratio, and collagen percentage was noted. The primary objective of this study was to determine the appropriate cutoff criteria for clinical utilization, as well as to investigate the association between intensity ratios and collagen percentage. RESULTS: Tumors with ratios ≤ 1.6 on the T2-weighted image and collagen content > 5.3% required more meticulous and sharp dissection for resection. CONCLUSIONS: The utilization of MRI analysis may offer some assistance, but not conclusive, in the prediction of tumour consistency.

A computer-aided polyp detection system in screening and surveillance colonoscopy: an international, multicentre, randomised, tandem trial.

BACKGROUND: Studies on the effect of computer-aided detection (CAD) in a daily clinical screening and surveillance colonoscopy population practice are scarce. The aim of this study was to evaluate a novel CAD system in a screening and surveillance colonoscopy population. METHODS: This multicentre, randomised, controlled trial was done in ten hospitals in Europe, the USA, and Israel by 31 endoscopists. Patients referred for non-immunochemical faecal occult blood test (iFOBT) screening or surveillance colonoscopy were included. Patients were randomomly assigned to CAD-assisted colonoscopy or conventional colonoscopy; a subset was further randomly assigned to undergo tandem colonoscopy: CAD followed by conventional colonoscopy or conventional colonoscopy followed by CAD. Primary objectives included adenoma per colonoscopy (APC) and adenoma per extraction (APE). Secondary objectives included adenoma miss rate (AMR) in the tandem colonoscopies. The study was registered at ClinicalTrials.gov, NCT04640792. FINDINGS: A total of 916 patients were included in the modified intention-to-treat analysis: 449 in the CAD group and 467 in the conventional colonoscopy group. APC was higher with CAD compared with conventional colonoscopy (0·70 vs 0·51, p=0·015; 314 adenomas per 449 colonoscopies vs 238 adenomas per 467 colonoscopies; poisson effect ratio 1·372 [95% CI 1·068-1·769]), while showing non-inferiority of APE compared with conventional colonoscopy (0·59 vs 0·66; p<0·001 for non-inferiority; 314 of 536 extractions vs 238 of 360 extractions). AMR in the 127 (61 with CAD first, 66 with conventional colonoscopy first) patients completing tandem colonoscopy was 19% (11 of 59 detected during the second pass) in the CAD first group and 36% (16 of 45 detected during the second pass) in the conventional colonoscopy first group (p=0·024). INTERPRETATION: CAD increased adenoma detection in non-iFOBT screening and surveillance colonoscopies and reduced adenoma miss rates compared with conventional colonoscopy, without an increase in the resection of non-adenomatous lesions. FUNDING: Magentiq Eye.

Endonasal endoscopic surgery for pituitary adenomas.

Pituitary adenomas are slow-growing, benign intracranial tumors that can be characterized as functional (hormone-producing) or non-functional (non-hormone producing). Symptoms therefore arise from either endocrinologic abnormalities or mass effect on surrounding structures resulting in symptoms such as visual impairment and headache. In the last two decades, technical innovations have shifted surgical resection of such adenomas to endoscopic endonasal approaches. In this review, we describe the evolving approach to pituitary adenomas in the modern endoscopic era, including preoperative multidisciplinary review, relevant surgical anatomy, and a description of the technical nuances of standard and expanded approaches to the anterior skull base.