Severe Obesity Associated With Pituitary Corticotroph Hyperplasia and Neoplasia.

OBJECTIVE: To investigate the incidence of corticotroph hyperplasia (CH) or lymphocyte infiltration in the pituitary of patients with obesity. METHODS: The pituitary and adrenal glands from 161 adult autopsies performed between 2010 and 2019 at our institution were reviewed. The clinical history, body mass index (BMI), and cause of death were recorded. Routine hematoxylin and eosin staining, reticulin staining, and immunohistochemical staining for adrenocorticotropic hormone, CD3, and CD20 were performed. The results were analyzed using the Fisher and chi-square statistics. Decedents were separated into 4 groups based on BMI (kg/m2): (1) lean (BMI, <25.0), (2) overweight (BMI, 25.0-29.9), (3) obesity class I (BMI, 30.0-34.9), and (4) obesity classes II to III (BMI, >34.9). RESULTS: CH/neoplasia was identified in 44 of 161 pituitary glands. Four (9.1%) of 53 lean patients had pituitary lesions, whereas 27.3% (12) of overweight, 22.7% (10) of obesity class I, and 40.9% (18) of obesity class II patients had hyperplasia (P < .0001). Small corticotroph tumors were identified in 15 patients; only 1 was a lean patient, and the tumor was associated with the Crooke hyaline change of nontumorous corticotrophs. The presence of CH and neoplasia was associated with adrenal cortical hyperplasia and lipid depletion. Microscopic foci of T and B lymphocytes were identified in the pituitaries of patients in each weight category; no independent association between BMI and lymphocyte inflammation was found. CONCLUSION: Our data indicate an association between CH/neoplasia and obesity. It remains unclear whether obesity is the cause or effect of adrenocorticotropic hormone and cortisol excess.

Adult Diffuse Astrocytic and Oligodendroglial Tumors.

Infiltrating gliomas comprise the most common group of primary intraparenchymal brain tumors and present a level of complexity which requires careful integration of histopathology and molecular diagnostics for optimal therapy. To this end, the fourth edition of the World Health Organization (WHO) Classification of Tumors of the Central Nervous System (CNS) has been followed by a series of publications by cIMPACT-NOW (the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy) incorporating molecular signatures to propose updated diagnostic categories in anticipation of the upcoming fifth edition of CNS tumor classification. Integration of histopathology, immunophenotyping, and molecular findings is profoundly changing the practice of diagnostic surgical neuropathology and enabling a more personalized approach to treating patients with gliomas.

Molecular Profiling of Pediatric and Adult Glioblastoma.

OBJECTIVES: Although glioblastoma (GBM) is rare in the pediatric population, it is the most common cause of death among children with central nervous system neoplasms. Recent molecular profiling of these neoplasms has demonstrated distinct differences in comparison to their adult counterparts. Moreover, many pediatric GBMs occur within the context of cancer predisposition syndromes, such as constitutional mismatch repair deficiency syndrome (CMMRD). Children with CMMRD who develop GBM exhibit a high tumor mutational burden and may benefit from treatment with immune checkpoint inhibitors. METHODS: We performed next-generation sequencing and immunohistochemistry for mismatch repair proteins in our cohort of pediatric and adult GBMs to further characterize the molecular profiles of these groups. RESULTS: We examined a total of 11 pediatric and 11 adult GBMs. Pediatric patients had a higher number of alterations compared to their adult counterparts. They also had a higher frequency of alterations in the mismatch repair genes, which can be detected by immunohistochemistry (IHC). We also identified one pediatric patient with CMMRD syndrome. CONCLUSIONS: Our study highlighted the distinct molecular differences between pediatric and adult GBM. We also demonstrated that pediatric patients have a higher frequency of alterations in the mismatch repair genes, which may render them susceptible to treatment with immune checkpoint inhibitors. These alterations can be detected using routine IHC and should be performed on all pediatric GBM.

Proteins inform survival-based differences in patients with glioblastoma.

BACKGROUND: Improving the care of patients with glioblastoma (GB) requires accurate and reliable predictors of patient prognosis. Unfortunately, while protein markers are an effective readout of cellular function, proteomics has been underutilized in GB prognostic marker discovery. METHODS: For this study, GB patients were prospectively recruited and proteomics discovery using liquid chromatography-mass spectrometry analysis (LC-MS/MS) was performed for 27 patients including 13 short-term survivors (STS) (≤10 months) and 14 long-term survivors (LTS) (≥18 months). RESULTS: Proteomics discovery identified 11 941 peptides in 2495 unique proteins, with 469 proteins exhibiting significant dysregulation when comparing STS to LTS. We verified the differential abundance of 67 out of these 469 proteins in a small previously published independent dataset. Proteins involved in axon guidance were upregulated in STS compared to LTS, while those involved in p53 signaling were upregulated in LTS. We also assessed the correlation between LS MS/MS data with RNAseq data from the same discovery patients and found a low correlation between protein abundance and mRNA expression. Finally, using LC-MS/MS on a set of 18 samples from 6 patients, we quantified the intratumoral heterogeneity of more than 2256 proteins in the multisample dataset. CONCLUSIONS: These proteomic datasets and noted protein variations present a beneficial resource for better predicting patient outcome and investigating potential therapeutic targets.

Acceptable Weight Ranges for Research Tissue Procurement and Biorepositories, 2015-2017.

Background: The Cooperative Human Tissue Network, Midwestern Division, is a National Cancer Institute-funded program that provides quality research biospecimens to qualified investigators. Consented human tissues are procured according to researcher specifications for weight (size) and preservation type; weights of samples in significant demand and limited supply are negotiated. Weights of procured tissues are entered into a dedicated biospecimen database. This study seeks to provide guidance for acceptable tissue weights for researchers. Methods: Tissue weights by year and anatomic site were retrieved from the database for primary malignant tissues. The total number of tissues included was 5141. Statistical evaluation of data included the number of tissues for each year, anatomic site as well as minimum, maximum, average weights, standard deviation, and standard error. Anatomic sites with few tissues were excluded. Results: "Stock price" type graphs were constructed to show an average as "volume" with both full weight ranges and range that accommodated 80% of tissues. Average weight and number of sample trends varied by anatomic site. Tissues fell into four weight groups; 10 and 90 percentile boundaries were calculated for each. Smallest average research tissue weights for middle 80% were recorded for prostate and oropharynx (140 mg). Second weight group included tonsil, thyroid, breast, oral cavity, larynx, pancreas, salivary gland, skin, tongue, lung, and parotid (265 mg). The third group included stomach, cervix, colon, esophagus, endometrium, bone, brain, bladder, small bowel, uterus, liver, kidney lymph node, adrenal, and ovary (513 mg). The fourth and heaviest weight group included soft tissue tumors and spleen (1201 mg). Conclusions: Since tissue weights are not usually included in recommendations for research tissue procurement or for frozen tissues stored in biorepositories, we offer this data as a practical guide to researcher acceptable tissue weights for selected sites based on a 3-year researcher request and acceptance history.

Histologically Proven Radiation-Induced Brainstem Glioma 93 Months After External Beam Radiotherapy for Pituitary Macroadenoma: Radiation Treatment Dose and Volume Correlation.

Patient is a 29-year-old with a history of recurrent growth hormone-secreting pituitary macroadenoma diagnosed 12 years prior to presentation. Eight years prior to current presentation, the patient underwent re-resection and received 50.4 Gy external beam radiotherapy (EBRT) in 28 fractions of 1.8 Gy each. Serial postradiation MRIs demonstrated regression in pituitary tumor size. Patient presented with new headaches 7.5 years after completing EBRT. Brain MRI demonstrated new FLAIR hyperintensity and contrast enhancement within the pons and medulla, corresponding to the 36 Gy isodose line of each radiation dose fraction. Differential diagnosis included radiation necrosis and radiation-induced glioma (RIG). The patient's neurologic exam worsened over the following 4 months. MRI showed progressive increase in mass effect, extent of FLAIR hyperintensity, and contrast enhancement in the brainstem. Stereotactic-assisted biopsy showed infiltrating astrocytoma with moderate atypia. A PubMed search showed this is the first case of histologically verified brainstem RIG correlated with 3-dimensional conformational radiation therapy dose and volume planning following EBRT for a pituitary adenoma. The rare occurrence of brainstem RIG after radiation therapy for pituitary tumor supports the need for long-term imaging monitoring of such patients.

Quantitative analysis of matrix metalloproteinase-2 mRNA expression in central and peripheral regions of gliomas.

Malignant gliomas are characterized by their invasiveness and angiogenesis. Matrix metalloproteinases (MMPs) degrade extracellular matrix and create a more permissive environment for cell invasion. We aimed to investigate for the presence of inter- and intratumoral heterogeneity in MMP-2 messenger RNA (mRNA) expression by means of quantitative analysis and to evaluate its prognostic impact in glioma patients. Representative sections from the center and periphery of tumors resected en bloc were taken fresh for study, stained with hematoxylin/eosin for histological evaluation, and immunohistochemically analyzed for Ki-67. MMP-2 mRNA expression was evaluated by real-time reverse transcriptase polymerase chain reaction (RT-PCR). There was MMP-2 expression in all analyzed tumors. By topographical dissection of surgical specimens, we found no differences in cell proliferation or density but significant differences with regard to MMP-2 mRNA expression between central and peripheral regions, being highest at the center of malignant gliomas. MMP-2 mRNA expression showed no prognostic influence on overall or disease-free survival. Our results demonstrate that MMP-2 is differentially expressed in central and peripheral regions of gliomas. Further studies are necessary to clarify the significance of these findings and their possible relevance in clinical practice.

Differences in mitochondrial function and antioxidant systems between regions of human glioma.

Metabolic features and oxidative stress have been extensively studied in cancer cells. However, comparative studies between cancer cell populations that coexist in human neoplastic tissue are not frequently available. The aim of the present study was to characterize markers of oxidative status and mitochondrial function in center vs. periphery of human fresh glioma samples; therefore, antioxidant systems, oxidative stress and mitochondrial parameters were assessed in gross total resections of gliomas. Mitochondrial protein and mitochondrial DNA content, enzymatic activities of mitochondrial oxidative and phosphorylative system, antioxidant mechanisms, mitochondrial H(2)O(2) production, oxygen consumption and cellular oxidative damage were measured in human gliomas. Concentric regions of human glioma tissue showed similar mitochondrial structural markers; conversely, the functionality of their isolated mitochondria was significantly different. In this way, the tumor periphery exhibited higher respiratory rate and fewer antioxidant systems than tumor center. Our results have expanded previous investigations, which report the presence of cell populations with different oxidative susceptibility in human brain tumor samples. This is, to our knowledge, the first study to investigate metabolic differences in concentric regions of gross total resections of glioma. Interestingly, the cancer cell population that exhibits an increased antioxidant capacity within the tumor mass might be responsible for tumor resistance to chemotherapy and radiotherapy.

Leptin increases proliferation of human steosarcoma cells through activation of PI(3)-K and MAPK pathways.

BACKGROUND: Serum leptin levels are strongly and directly related to fat body mass (FBM). Bone mineral density (BMD) increases with FBM, and obesity has a protective effect against osteoporosis. We have previously demonstrated that leptin therapy has a significant effect in preventing ovariectomy-induced bone loss in rats and leptin also exerts direct osteogenic effects in vitro. To obtain a better understanding of the physiology and pharmacology of leptin in bone metabolism, we evaluated the leptin-induced signal transduction pathways and proliferative response in the human osteosarcoma cell line Saos-2. MATERIAL/METHODS: Saos-2 cell lines were used. Leptin receptor common form (OB-Ra) and long form (OB-Rb) were detected by RT-PCR and immunocytochemistry. PI(3)-K activity was immunoprecipitated using antibodies directed against tyrosine-phosphorylated proteins and IRS-1. The activated form of p42/p44 MAPK was investigated in cytosolic extracts of confluent Saos-2 in response to leptin. RESULTS: In this study, we tested the hypothesis that leptin might be a mediator linking obesity and bone cell proliferation. We found that Saos-2 cells expressed OB-Ra and OB-Rb. Leptin (10 nmol/L - 2 umol/L) caused a significant increase in the activation of PI (3)-K that was accompanied by an increase in cell proliferation dose dependently based on the [3H]-thymidine incorporation. The specific PI (3)-K inhibitors LY294002 and wortmannin blocked leptin-induced cell proliferation. Interestingly, leptin activated MAPK and the specific MAPK-inhibitor PD98059 blocked DNA synthesis induced by leptin. CONCLUSIONS: Our data support the hypothesis that leptin may increase bone mass by stimulating osteoblast proliferation through activation of the P1 (3)-K and MAPK signaling pathways.

Is ghrelin the culprit for weight loss after gastric bypass surgery? A negative answer.

BACKGROUND: Ghrelin is a potent appetite stimulator, mainly synthesized in the stomach. Paradoxically, obese subjects have lower plasma ghrelin than lean subjects and increase their weight in spite of low ghrelin levels. The role of ghrelin in weight regulation after bariatric surgery is still controversial. The aim of this study was to evaluate whether rapid weight loss after laparoscopic Roux-en-Y gastric bypass surgery (LRYGBP), was associated with changes in plasma ghrelin levels. In addition, we determined the acute impact of LRYGBP on insulin resistance and adiponectin levels. METHODS: 49 morbidly obese subjects who underwent LRYGBP were studied. 19 subjects who underwent other laparoscopic gastrointestinal surgeries acted as the control group. Fasting plasma levels of ghrelin, insulin and adiponectin were determined preoperatively and 2 hours, 10 days and 6 months postoperatively. RESULTS: At 2 hours after LRYGBP, there was a significant reduction in ghrelin and adiponectin levels, which coincided with elevated plasma glucose and insulin levels. Interestingly, once glucose and insulin levels normalized at 6 months after surgery, ghrelin also normalized. Adiponectin reached pre-surgical levels at 10 days after LRYGBP and continued to significantly rise until 6 months postoperatively. CONCLUSION: Weight loss after LRYGBP occurs in spite of the absence of significant changes in plasma ghrelin levels. Improvement of insulin resistance occurred within 10 days after surgery, and could be related to the normalization of adiponectin levels. This data questions the role of peripheral ghrelin as a cause of weight loss in obese humans after LRYGBP.

Microdissection genotyping of gliomas: therapeutic and prognostic considerations.

Molecular anatomic pathology represents the blend of traditional morphological methods and the multigene approach to determine cancer-related gene alterations for diagnostic and prognostic purposes. Microdissection genotyping was utilized to characterize 197 gliomas with targeted microdissection of 2-7 areas spanning the spectrum of histologic types and grades. The methodology described herein is complementary to the existing realities of pathology practice. The technique utilizes paraffin-embedded fixative-treated tissue of small sample size after the primary morphological examination by the pathologist. Molecular information derived from microdissection genotyping in combination with the traditional histological information, results in an enhanced understanding of glioma formation and biological progression leading to improvements in diagnosis and prediction of prognosis. In all, 100% or 32 of 32 cases with at least partial treatment response was observed in neoplasms possessing the 1p or 1p/19q loss. The 19q loss alone without coexisting 1p showed no improvement in treatment response. Gliomas lacking 1p loss with only allelic loss involving 3p, 5q, 9p, 10q and 17p showed unfavorable outcome of only 35%, or six of 17 cases with treatment response. In addition, the determination of fractional allelic loss (favorable/unfavorable), was a very good independent predictor of biological behavior. These findings emphasize the importance of determining the cumulative pattern of mutational damage on 16 distinct sites or more, especially in the presence of 1p loss which in isolation or in combination with 19q is a favorable prognostic factor for therapeutic response.

Gliosarcoma with epithelial differentiation: immunohistochemical and molecular characterization. A case report and review of the literature.

Few reported cases of gliosarcomas or glioblastomas with epithelial-like areas exist. Most cases were originally diagnosed as metastatic carcinoma. Focal expression of glial fibrillary acidic protein has helped characterize these tumors as having a glial origin. We report a case of gliosarcoma with multifocal, extensive areas of well-differentiated carcinoma; demonstrating squamous and glandular differentiation. The expression of glial fibrillary acidic protein and epithelial phenotype were mutually exclusive. We performed extensive immunohistochemical analyses and comparative genotypic analysis using microdissection to secure representative glial and epithelial components. Loss of heterozygosity was analyzed with a panel of 12 polymorphic microsatellite markers designed to indicate allelic loss and situated in proximity to known tumor suppressor genes located on chromosomes 1p, 9p, 10q, 17p and 19q. We found comparable patterns of acquired allelic loss between the glial and carcinomatous components, strongly supporting the monoclonal origin of this neoplasm. This case represents an extreme form of phenotypic divergence in a malignant glioma, and constitutes a difficult diagnostic challenge. This heterogeneity reflects the potential for a range of phenotypic expression in malignant gliomas that needs to be recognized. We suggest microdissection genotyping as a molecular technique to better characterize these tumors.