Is radiomics a useful addition to magnetic resonance imaging in the preoperative classification of PitNETs?

BACKGROUND: The WHO 2021 introduced the term pituitary neuroendocrine tumours (PitNETs) for pituitary adenomas and incorporated transcription factors for subtyping, prompting the need for fresh diagnostic methods. Current biomarkers struggle to distinguish between high- and low-risk non-functioning PitNETs. We explored if radiomics can enhance preoperative decision-making. METHODS: Pre-treatment magnetic resonance (MR) images of patients who underwent surgery between 2015 and 2019 with available WHO 2021 classification were used. The tumours were manually segmented on the T1w, T1-contrast enhanced, and T2w images using 3D Slicer. One hundred Pyradiomic features were extracted from each MR sequence. Models were built to classify (1) somatotroph and gonadotroph PitNETs and (2) high- and low-risk subtypes of non-functioning PitNETs. Feature were selected independently from the MR sequences and multi-sequence (combining data from more than one MR sequence) using Boruta and Pearson correlation. Support vector machine (SVM), logistic regression (LR), random forest (RF), and multi-layer perceptron (MLP) were the classifiers used. Data imbalance was addressed using the Synthetic Minority Oversampling TEchnique (SMOTE). Performance of the models were evaluated using area under the receiver operating curve (AUC), accuracy, sensitivity, and specificity. RESULTS: A total of 222 PitNET patients (train, n = 149; test, n = 73) were enrolled in this retrospective study. Multi-sequence-based LR model discriminated best between somatotroph and gonadotroph PitNETs, with a test AUC of 0.84, accuracy of 0.74, specificity of 0.81, and sensitivity of 0.70. Multi-sequence-based MLP model perfomed best for the high- and low-risk non-functioning PitNETs, achieving a test AUC of 0.76, accuracy of 0.67, specificity of 0.72, and sensitivity of 0.66. CONCLUSIONS: Utilizing pre-treatment MRI and radiomics holds promise for distinguishing high-risk from low-risk non-functioning PitNETs based on the latest WHO classification. This could assist neurosurgeons in making critical decisions regarding surgery or alternative management strategies for PitNETs after further clinical validation.

Droplet digital PCR (ddPCR) using FFPE DNA to assess methylation status of MGMT gene among patients with IDH mutant astrocytoma and IDH wild-type glioblastoma.

MGMT promoter methylation analysis in formalin-fixed paraffin-embedded (FFPE) tissues can be challenging since the DNA obtained is often fragmented. Bisulfite conversion, which is essential to determine methylation status, further degrades DNA. While conventional methylation-specific PCR (MSP) and pyrosequencing assays have long been used to determine the methylation status of MGMT, this study was designed to determine the utility of one-tube DNA extraction method coupled with a droplet digital PCR (ddPCR) assay, to study the epigenetic changes in the promoter region of the MGMT gene using DNA obtained from FFPE.The FFPE blocks of 30 (n=30) patients with Central Nervous System (CNS) WHO grade 4 tumours, previously tested by MSP (2011-2021) were retrieved; DNA was extracted using one-tube extraction method and bisulfite converted. All converted samples were analyzed for methylation status of the MGMT promoter region with a laboratory designed Methylation-Specific ddPCR (MS ddPCR) using degenerate primers and probes that were labelled with FAM or HEX flurocein dye.Of the 30 cases, 20 cases were MGMT methylated and 10 cases were unmethylated by MS ddPCR. The results of MS ddPCR were then compared with those obtained by MSP and found to be concordant in 93.3% (28/30) of the cases and discordant in 2 cases. The Cohen's kappa coefficient (κ) was 0.84. The sensitivity, specificity, positive predictive value and negative predictive value of the assay in detecting the methylation status was found to be 95%, 90%, 95% and 90%.The results show that MS ddPCR is a valuable tool to detect the methylation status of MGMT in FFPE with high sensitivity. This method is cost-effective and easy to perform and could be an attractive alternative to the routine method of MSP.

Trigeminal hybrid nerve sheath tumor - a case report and literature review.

BACKGROUND: Hybrid nerve sheath tumors (HNST) contain elements of more than one established sub-type of nerve sheath tumor and have been recently recognized in the 2016 WHO classification of central nervous system tumors. While common in the peripheral nerves and extracranial branches of cranial nerves, only one case has been previously documented of an intracranial HNST arising from a cranial nerve. CASE DESCRIPTION: We describe a large, multi-compartmental intracranial hybrid nerve sheath tumor arising from the trigeminal nerve in a 22-year-old lady who presented with clinical and radiological features suggestive of a right cerebellopontine angle mass. Histopathological examination following retrosigmoid excision of the tumor revealed histological and immunohistochemical features of a schwannoma and a perineurioma. CONCLUSIONS: HNSTs are likely to be underreported in the intracranial region. The clinical course of these tumors and the reason for their occurrence in this location are not known.

Supratentorial primary paraganglioma with good long-term outcome following radical excision.

BACKGROUND: Paragangliomas are tumours of extra-adrenal paraganglia. They may metastasize to the brain but primary paragangliomas are exceedingly rare in the supratentorial region and long-term outcomes after surgery is largely unknown. This description of an excellent outcome 13 years following surgery in a 40-year-old gentleman with a primary paraganglioma near the falx provides an important perspective on the value of gross total resection in these tumours. We also review the options for adjuvant therapy in tumours that cannot be excised completely. CASE DESCRIPTION: We describe a supratentorial paraganglioma in the parasagittal region in a 40-year-old gentleman who presented with clinical and radiological features suggestive of a right parafalcine meningioma. Histopathological examination following gross total excision of the tumour revealed histological and immunochemical features of a paraganglioma. A detailed search for a systemic primary was negative and the patient remains disease-free 13 years after the surgery. CONCLUSIONS: Differentiating between tumours arising primarily and those that are metastatic deposits in the central nervous system requires long-term follow-up and monitoring for the appearance of occult primary tumours. Gross total resection is likely to provide good long-term outcomes.

Adult renal angiomyolipomas: A retrospective analysis of the histological subtypes and their clinicoradiological correlates.

Background: Renal angiomyolipomas (AMLs) are rare, benign mesenchymal tumors of the kidney. Asian data on the prevalence of the subtypes of AMLs and their association with tuberous sclerosis are sparse prompting us to evaluate the clinicopathological characteristics of these tumors. Materials and Methods: We included cases diagnosed from 2001 to 2021 extracting demographic details, clinical presentation, syndromic association with tuberous sclerosis, and preoperative clinicoradiological features from the electronic medical records. Results: Ninety-five cases of adult renal AML were diagnosed among 2402 renal tumors, a prevalence of 3.95%. Forty tumors (42%) were detected incidentally; two patients had life-threatening retroperitoneal hemorrhage. Tuberous sclerosis complex (TSC) was associated with ten cases (10.5%). These patients were a decade younger than those in the non-TSC group (P = 0.008) and had bilateral, multiple, and larger tumors (P = 0.0009, 0.001, and 0.047, respectively). Microscopically, classic and epithelioid subtypes were seen in 87 (91.6%) and 8 cases (8.4%), respectively. Hemorrhage was more common in the epithelioid subtype (P = 0.13). HMB-45, melan-A, and smooth muscle actin immunohistochemistry were useful in cases which lacked the prototypical classic histology and for confirming a diagnosis of epithelioid AML. Conclusions: The prevalence of renal AML in our series was four times higher, and the mean age at diagnosis was a decade earlier than that reported in Western literature but similar to data from two Asian countries. Similar studies from other countries will help ascertain if these differences in prevalence can be attributed to ethnic differences.

Accuracy of Xpert MTB/RIF Ultra for the diagnosis of tuberculosis in adult patients: a retrospective cohort study.

OBJECTIVES: The value of the "trace" result in Xpert Ultra for diagnosing active tuberculosis (TB) remains unclear. Our study evaluated the diagnostic accuracy of Xpert MTB/RIF Ultra (Xpert Ultra) (Cepheid, Sunnyvale, USA) over Xpert MTB/RIF (Xpert) (Cepheid, Sunnyvale, USA) and mycobacterial culture when compared with a composite reference standard (CRS). METHODS: A retrospective single-center observational study was conducted in a tertiary care hospital in South India. Over three months, patients (aged ≥15 years) data on Xpert Ultra tests and mycobacterial culture of pulmonary and extrapulmonary samples were extracted from their electronic medical records. Patients were defined as TB cases based on the CRS criteria. Sensitivity, specificity, positive and negative predictive values of diagnostic tests were calculated by comparing them to the CRS. RESULTS: Xpert Ultra was more sensitive (87.8%) than Xpert (72.1%) and culture (44.1%). The specificity of Xpert Ultra was lower (98.1%) than those of Xpert (100%) and culture (100%). The sensitivity (92%) and specificity (100%) of Xpert Ultra were highest when performed on pus samples. CONCLUSIONS: Xpert Ultra with the trace category is superior to the conventional Xpert, and mycobacterial culture in identifying TB.

Telomerase Reverse Transcriptase Promoter Mutations in A Cohort Of Adult Gliomas - Clinicopathological Correlates.

Background: Introduction: Gliomas were previously classified histologically, although now the latest WHO classification incorporates several molecular markers to classify these. Detection of TERT promoter mutations is assuming increased importance due to its relevance to prognostication. Objective: : The aim of this study was to determine the frequency of TERT promoter mutations, association of TERT promoter mutations with other molecular alterations and to assess the role of TERT promoter mutations in overall survival and progression-free survival in relation to histological and molecular glioma subtypes. Materials and Methods: This study analyzed a cohort of 107 adult patients with diffuse gliomas, WHO grades II and III and glioblastoma, by immunohistochemistry for IDH and ATRX mutations, FISH for 1p/19q co-deletions and PCR sequencing for TERT promoter mutation. Further, five glioma molecular sub-groups were derived using three molecular alteration and included the sub-groups with: i) IDH mutations only, ii) IDH and TERT mutations only, iii) IDH and 1p/19q co-deletion only, iv) Triple negative, and v) Triple positive. Results: IDH mutations and 1p/19q co-deletions were individually and significantly associated with an improved progression free (P = 0.001 and P = 0.002, respectively) and overall survival (P = 0.000 and P = 0.005, respectively) in the present cohort of gliomas. TERT promoter mutations occurred frequently in anaplastic oligodendrogliomas (94%), oligodendrogliomas (87.5%) and glioblastomas (54%). Sub-division into molecular sub-groups showed that the triple-positive tumors carried the best prognosis, followed by IDH only, triple negative and finally the TERT mutation only tumors (P < 0.000). Conclusion: : This indicates that sub-classification using these molecular markers separates tumors into prognostically relevant categories.

Meningiomas - transition from traditional histological grading to molecular profiling in WHO CNS5: A Review.

Despite being the most common primary intracranial tumor, meningiomas are classified largely based on histological features. The current system of grading has been shown to be unsatisfactory due to its poor reproducibility as well as the considerable variability within grades. With the increasing availability of genomic and epigenomic profiling, several markers have been suggested to correlate with the location, histological subtype, and clinical behavior of meningiomas. These developments have enabled the development of targeted therapy, as well as individualized use of currently available adjuvant methods. These include copy number alterations (CNAs), specific genetic abnormalities (germline and sporadic), and genome-wide methylation profiles. In this review, we recapitulate the changes in the classification of meningiomas thus far, discuss the various histological subtypes recognized, and present the available literature on the genetic and epigenetic profiles of meningiomas. The recognition and further study of these markers have the potential to usher in an era of personalized therapy in the management of meningiomas, vastly improving outcomes as has been observed in the case of several other tumors.

Impact of Grade on Survival in Pleomorphic Xanthoastrocytoma and Low Prevalence of BRAF V600E Mutation.

BACKGROUND: The prevalence of BRAFV600E mutations in pleomorphic xanthoastrocytoma (PXA) World Health Organization (WHO) Grade 2 and PXA WHO Grade 3 reported varies from 60% to 80%, yet the prognostic implications remain unclear. METHODS: We reviewed the demographic and clinicoradiologic data of 20 PXAs WHO Grade 2 and 13 PXAs WHO Grade 3, operated between 2007 and 2020, to ascertain extent of excision, recurrence, progression-free survival (PFS), and overall survival (OS). PXAs WHO Grade 3 were defined by the presence of >5 mitoses/high-power field. PXAs WHO Grade 3 received adjuvant radiation therapy and chemotherapy whereas PXAs received radiation therapy if subtotally excised. All samples were analyzed for the presence of BRAFV600E mutation using DNA obtained from paraffin blocks using droplet-digital polymerase chain reaction. RESULTS: The median patient age at diagnosis was 22 years with a male preponderance. BRAFV600E mutations were noted in 30% of tumors; 8 PXAs WHO Grade 2 and 2 PXAs WHO Grade 3. Recurrence occurred in 6 of 13 PXA WHO Grade 3 (55%) and 1 of 20 PXAs WHO Grade 2 (5%). At median follow-up of 45 months, the OS was 54 months and 33 months in the PXA WHO Grade 2 and PXA WHO Grade 3 groups, respectively (P = 0.02). OS and PFS did not differ between BRAF-mutated and BRAF-negative tumors. CONCLUSIONS: BRAFV600E mutations are less frequent in our population than reported in the literature. The BRAF mutation does not significantly impact OS and PFS. PXAs WHO Grade 3 are a distinct clinical entity, associated with worse PFS and OS than PXAs WHO Grade 2.

ZFTA (Zinc Finger Translocation Associated) Fusion in Supratentorial Ependymomas: Low Prevalence in South Asians and No Correlation with Survival.

BACKGROUND: Supratentorial ependymomas (STEs) are an aggressive group of ependymomas, topographically distinct from their posterior fossa and spinal counterparts. Zinc finger translocation associated (ZFTA) fusion-positive cases have been reported to account for the majority of STEs, although data on its association with poorer outcomes are inconsistent. MATERIALS AND METHODS: We assessed the prevalence of the ZFTA fusion by reverse-transcription polymerase chain reaction and fluorescence in situ hybridization in a cohort of 61 patients (68 samples) with STE. Our primary outcome was to determine the role of the ZFTA fusion on progression-free and overall survival of patients with STE. Our secondary objectives were to assess the impact of ZFTA fusion on nuclear factor (NF)-kB pathway signaling via surrogate markers of this pathway, namely COX-2, CCND1, and L1 cell adhesion molecule. RESULTS: ZFTA fusion was noted in 21.3% of STEs in our cohort. The presence of this rearrangement did not significantly impact the progression-free or overall survival of patients with STEs and was not associated with upregulation of markers of the NF-kB pathway. Only gross total resection was significantly associated with better progression-free survival. CONCLUSIONS: In contradiction to previous reports from across the world, the ZFTA fusion is far less prevalent among our population. It does not appear to drive NF-kB signaling or significantly affect outcomes. Gross total resection must be attempted in all cases of STE and adjuvant radiation and/or chemotherapy employed when gross total resection is not achieved.

Radiation-Induced Intravascular Papillary Endothelial Hyperplasia in a Cavernous Sinus Hemangioma.

Background: Cavernous sinus hemangiomas are benign vascular tumors of the cavernous sinus. Intravascular papillary endothelial hyperplasia (IPEH), also known as Masson's angioma is a rare, aberrant thrombus organization occurring independently or in pre-existent lesions, and information on its occurrence in the intracranial region, or its management is sparse. Objective: We aim to describe a case of IPEH occurring in a pre-existing cavernous sinus hemangioma, treated with surgical excision and radiation therapy, providing insight into the appropriate treatment of these tumors and their response to therapy. Materials and Methods: We describe a right cavernous sinus hemangioma, recurring after initial radiation therapy and requiring surgical excision, at which point the presence of IPEH was noted. A sellar recurrence following partial excision was treated with hypofractionated Stereotactic radiotherapy (SRT), and this provided an excellent long-term outcome. Conclusions: Cavernous sinus hemangiomas are treated with surgical excision or primary radiation therapy. IPEH must be looked for in all excised specimens, as there are no radiological features that indicate its presence, and it may resemble the original lesion histologically. When detected, adjuvant radiation must be administered as the IPEH responds well to the use of radiation therapy.

A Comparison of Long-Term Treatment Outcomes Between Giant and Nongiant Craniopharyngiomas.

BACKGROUND: There is limited literature on outcomes after surgical treatment of giant craniopharyngiomas in adult and pediatric patients. METHODS: A retrospective review of 159 patients undergoing surgery for craniopharyngiomas at a single institution was performed. Patients with giant craniopharyngiomas (maximum dimension ≥4.5 cm) were compared with nongiant tumors in terms of various clinical and radiological parameters and long-term surgical outcomes. Extent of resection was determined by postoperative magnetic resonance imaging. Factors associated with post-treatment obesity were also analyzed. RESULTS: Giant craniopharyngiomas (n = 66) were characterized by higher rates of childhood presentation, visual impairment, neurological deficits, multicompartmental involvement, and hydrocephalus as compared with nongiant tumors (n = 139). Giant tumors also were less likely to undergo transsphenoidal resection and were associated with a higher rate of postoperative neurological morbidity. There were no significant differences between the 2 groups in terms of extent of resection, use of postoperative radiation therapy, and long-term endocrinological outcomes. Overall recurrence rates over a mean follow-up period of 4.1 years were similar between giant and nongiant tumors; however, recurrences after presumed gross total resection/near total resection were significantly higher in the former subgroup versus the latter (39.4% vs. 18.4%; P = 0.044). Risk factors for post-treatment obesity in giant craniopharyngiomas included adult age (P = 0.001), preoperative obesity (P = 0.003), and hypothalamic involvement (P = 0.012). CONCLUSION: Gross total resection/near total resection of giant craniopharyngiomas can be achieved at rates comparable to nongiant tumors. However, there remains a greater risk of postoperative neurological morbidity. Radiation therapy mitigates the risk of recurrence on long-term follow-up.

USP8, USP48, and BRAF mutations differ in their genotype-phenotype correlation in Asian Indian patients with Cushing's disease.

PURPOSE: To estimate the prevalence of USP8, USP48, and BRAF mutations in patients with Cushing's disease (CD) from the Indian subcontinent, and determine their genotype-phenotype correlation. METHODS: We prospectively recruited 46 patients with CD who underwent surgery between September 2015 and July 2019 at our institute. Fresh frozen tumour tissue was obtained in all patients. Using Sanger sequencing, the presence of somatic USP8 mutations was documented and the frequency of USP48 and BRAF mutations in USP8 wild-type corticotroph adenomas was determined. Clinical, hormonal, and surgical data were then compared between USP8-, USP48- and BRAF-variant carriers and patients with wild-type tumours. RESULTS: Signature USP8 mutations were detected in 17 (37%) patients. Of the 29 USP8 wild-type adenomas, 4 (13.8%) harboured USP48 mutations, one of them being a splice-site mutation that has previously not been described. BRAF mutations were not found in any of the 29 patients. Corticotroph adenomas with USP8 mutations had a higher incidence of Crooke's hyaline change than wild-type tumours (70.6 vs. 37.9%, p = 0.032). Adenomas with USP48 mutations had a higher rate of cavernous sinus invasion than their wild-type counterparts (50 vs. 4%, p = 0.042). No other significant phenotypic difference could be established between mutant and wild-type tumours. CONCLUSIONS: The prevalence of USP8 mutations in our series of patients with CD was 37%. The prevalence of USP48 mutations in USP8 wild-type adenomas was 13.8%, including a novel splice-site mutation. BRAF mutations were not found in any USP8 wild-type tumour. USP8-mutants showed significantly more Crooke's hyaline change and USP48-mutants were more likely to demonstrate cavernous sinus invasion.

Prevalence and Pattern of Leptomeningeal Pigmentation in the Human Brain and Its Role in the Safe Surgical Excision of Extra-Axial Brain Tumors.

BACKGROUND: Although leptomeningeal melanin pigmentation is well-known, it is not described in the neurosurgical literature. Dark pigmentation native to these transparent membranes might have microsurgical relevance in identifying a plane of dissection. OBJECTIVE: To describe the prevalence of leptomeningeal pigmentation and determine whether its recognition helps during microsurgical excision of extra-axial brain tumors. MATERIALS AND METHODS: : This was a prospective cross-sectional observational study in cadavers and neurosurgical patients. Eight adult cadaveric brains were examined for leptomeningeal pigmentation and biopsies taken for histological studies. A total of 126 patients undergoing surgery for cerebellopontine angle and suprasellar lesions were included in the clinical study. The surgeon determined whether the recognition of pigmentation was useful during microneurosurgical arachnoid dissection. RESULTS: Seven of 8 cadavers (87.5%) had leptomeningeal pigmentation on the ventral pons, optic chiasm, lamina terminalis, olfactory tract, and gyrus rectus and infrequently on the cerebral convexities. The prevalence of pigmentation was 76.9% in the clinical study, was seen in all pediatric patients, and was significantly higher in males (P = 0.009), with no significant association with skin color. Immunochemistry identified the pigmentation as melanin. Recognition of this pigmentation was deemed to be useful during tumor excision in 78% of the cases. CONCLUSIONS: Leptomeningeal melanin pigmentation has a prevalence of 76% to 87% in the Indian population and is more often seen in younger males. It is most commonly identified overlying the ventral brain stem and optic chiasm. Recognition of its presence is helpful during arachnoid dissection during most cerebellopontine angle and suprasellar tumor resections.

Mass Spectrometry Imaging Deciphers Dysregulated Lipid Metabolism in the Human Hippocampus Affected by Temporal Lobe Epilepsy.

Temporal lobe epilepsy (TLE) is the most prevalent form of human epilepsy, often accompanied by neurodegeneration in the hippocampus. Like other neurological diseases, TLE is expected to disrupt lipid homeostasis. However, the lipid architecture of the human TLE brain is relatively understudied, and the molecular mechanism of epileptogenesis is poorly understood. We performed desorption electrospray ionization mass spectrometry imaging of 39 fresh frozen surgical specimens of the human hippocampus to investigate lipid profiles in TLE with hippocampal sclerosis (n = 14) and control (non-TLE; n = 25) groups. In contrast to several previous studies on animal models of epilepsy, we report reduced expression of various important lipids, notably phosphatidylcholine (PC) and phosphatidylethanolamine (PE), in the human TLE hippocampus. In addition, metabolic pathway analysis suggested the possible dysregulation of the Kennedy pathway in TLE, resulting in striking reductions of PC and PE levels. This revelation opens up opportunities to further investigate the associated molecular mechanisms and possible therapeutic targets for TLE.

Growth hormone storm following infarction of a residual growth hormone secreting pituitary macroadenoma.

BACKGROUND: Thyrotroph pituitary adenomas have been reported to be a rare cause of 'thyroid storms', causing myriad metabolic and autonomic disturbances. In this case, we describe the second reported case in literature of a 'GH storm' in an infarcted somatotroph adenoma.Case description: We describe a residual invasive somatotroph macroadenoma that underwent infarction, producing a dramatic elevation in serum GH levels. While infarction of adenomas may in some cases lead to remission, the patient went on to require re-surgery and re-radiation due to growth of the residual viable tumour.Conclusions- 'GH storms' are rare but interesting events that may occur in somatotroph adenomas. Infarction or apoplexy must be considered when managing residual adenomas.

A clinicoradiological analysis of silent corticotroph adenomas after the introduction of pituitary-specific transcription factors.

BACKGROUND: Silent corticotroph adenomas (SCAs) are a rare subtype of non-functional pituitary adenoma. While it has been suggested that they are more aggressive and recur more frequently following excision, there is limited literature on the optimum treatment strategy for these tumors, especially regarding the role of radiation therapy in incompletely resected tumors. METHOD: We assimilated data from 62 SCAs and 238 other non-functional adenomas (ONAs), defined according to the WHO 2017 criteria that incorporates transcription factor analysis. We compared their clinicoradiological characteristics, such as hormonal levels, tumor configuration, size, and invasiveness. For 52 SCAs and 205 ONAs with serial follow-up imaging, we studied outcomes for progression after subtotal resection with or without radiation therapy or recurrence after gross total resection. Kaplan Meier analysis for recurrence or progression was used to determine the need for a differential treatment strategy for SCAs compared with other non-functional adenomas specifically concerning the role of radiotherapy. RESULTS: Patients with SCAs present at a younger age than ONAs (43.9 years vs. 48.2 years, p = 0.014), with larger (14.9 cc vs. 9.7 cc, p = 0.006) and more invasive adenomas (61.2% vs. 45.8%, p = 0.021). Overall, SCAs are more likely to recur or progress (48.7 vs. 15.7%, p < 0.001) following excision than ONAs, with significantly poorer event-free survival (Log rank test p < 0.001). Early adjuvant radiotherapy provides favorable outcomes among SCAs with postoperative residual tumor, on par with ONAs. Multivariate analysis identified male gender (HR: 2.217; p = 0.017), MIB index ≥ 3% (HR: 2.116; p = 0.012), and SCA tumor pathology (HR: 3.787; p < 0.001) as factors predicting recurrence. CONCLUSIONS: Based on the results of this retrospective, single-center review of 300 non-functional adenomas, we conclude that silent corticotroph adenomas are an aggressive subtype of non-functional pituitary adenomas that are larger, more likely to be invasive, and tend to recur more frequently after a subtotal excision compared with other non-functional adenomas. A gross total resection must be attempted whenever possible and earlier adjuvant radiation is recommended when re-surgery for residual tumor is difficult.

Impact of Experience on Outcomes After Endoscopic Transsphenoidal Surgery for Acromegaly.

OBJECTIVE: Acromegaly is a syndrome of metabolic alterations secondary to increased growth hormone levels from a somatotroph pituitary adenoma. A multidisciplinary approach beginning with surgery, followed by adjuvant radiation or medical therapy for residual disease, is considered standard of care. Several factors affect the likelihood of remission after surgery, but the impact of surgical experience on remission rates has not been adequately assessed. METHODS: Retrospective review of 203 patients, divided into 2 eras (era 1, 102 patients; era 2, 101 patients) of patients who underwent transsphenoidal surgery for acromegaly by a single surgeon over 11 years, was performed, determining the effect of surgical experience on rates of remission and various complications. Remission was defined according to the 2014 Endocrine Society Clinical Practice Guideline. RESULTS: The rate of surgical remission was 40.6% (62.9% among noninvasive adenomas). Rates of surgical remission significantly improved in the latter half of this cohort (31.2% in the first half vs. 50% in the second half), despite other factors being comparable. On multivariate analysis, surgeon experience, cavernous sinus invasion, and preoperative growth hormone levels affected the rates of surgical remission. Rates of cerebrospinal fluid leak and hypopituitarism were lower in the second half, whereas resolution of acromegaly-associated comorbidities was increased. CONCLUSIONS: We report, in this large single-surgeon review of endoscopically operated acromegaly cases, increased rates of surgical remission and reduced complications with increasing surgeon experience. The overall experience of the treating team in dealing with perioperative and intraoperative factors also contributes to improved outcomes.

Neuroimaging of pediatric infratentorial tumors and the value of diffusion-weighted imaging (DWI) in determining tumor grade.

BACKGROUND: Diffusion-weighted imaging (DWI) provides information about the cellular density of tumors. This feature is useful in grading and identifying different tumor types. PURPOSE: To assess the value of diffusion restriction and apparent diffusion coefficient (ADC) values in differentiating pediatric infratentorial tumors. MATERIAL AND METHODS: This was a retrospective review of the magnetic resonance imaging (MRI) of 82 children (age range 1-16 years) with infratentorial tumors. Histopathological grading after surgical excision/biopsy was categorized as low grade (WHO grades I and II) (n = 31; 29 pilocytic astrocytomas, 2 ependymomas) and high grade (WHO grade III and IV) (n = 51; 40 medulloblastomas, 8 anaplastic ependymomas, 1 anaplastic astrocytoma, 2 atypical rhabdoid teratoid tumors [ATRT]). MRI features and ADC values were compared among tumor types and grades using a two-tailed t test, Mann-Whitney U test for continuous data and Chi-square test for categorical variables. RESULTS: Diffusion restriction and low ADC value was a feature of high-grade tumors (P<0.001). The mean ADC values of the low-grade and high-grade tumors were 1.567 × 10-3mm2/s and 0.661 × 10-3mm2/s, respectively. Using 0.9 × 10-3mm2/s as the cut-off value, the sensitivity, specificity, positive and negative predictive values for differentiating the grades was 87%, 100%, 100%, and 81.8%, respectively. Significant differences were found between the mean ADC values of the individual tumor types (P<0.05), except between medulloblastoma and ATRT. CONCLUSION: ADC values and visual assessment of diffusion restriction are useful in tumor grading. The individual tumor types can be identified by an algorithmic approach, using DWI in conjunction with other described MRI features.