Application Of Prolactin In The Diagnosis Of Enlarged Pituitary Stalk And Lipid Metabolism In Intracranial Germ Cell Tumors

PART1:The value of serum prolactin in the differential diagnosis of pituitary stalk thickeningObjective:The differential diagnosis of pituitary stalk thickening is difficult.The aim of the study is to evaluate the value of prolactin(PRL)in differentiating malignant from benign pituitary stalk thickening.Method:Patients with imaging features of pituitary stalk thickening and confirmed etiological diagnosis were retrospectively enrolled in Peking Union Medical College Hospital from Jan 2014 to May 2017.Baseline PRL was collected.The included patients were divided into benign and malignant groups based on etiologies.Benign pituitary tumors,hypophysitis,L-type histiocytosis,Rathke's cleft cyst,and pituitary abscess were classified as benign lesions,while intracranial germ cell tumor and metastasis were classified as malignant lesions.The PRL level was compared between benign and malignant groups.The ROC curve was plotted to determine the best cut-off value of PRL to predict the malignant pituitary stalk thickening,and the area under ROC curve(AUC),corresponding sensitivity and specificity was calculated.The diagnosis accuracy of cut-off point PRL 1.27×upper limit of normal(ULN)suggested in previous study was evaluated in patients with similar characteristics in our cohort after exclusion of patients younger than 15,without central diabetes insipidus,or with Rathke's cleft cyst,craniopharyngioma,or metastasis.Sensitivity analysis was conducted by classifying L-type histiocytosis as malignant lesion.Results:A total of 110 patients were included in final analysis.There were 73(66.3%)benign cases,and 37(33.7%)malignant cases.The PRL level in malignant group was 1.32×ULN(P5-P95 0.24-5.49),which was significantly higher than PRL in the benign group(0.75×ULN,P5-P95 0.16?3.94)(P<0.001).PRL of 1.152×ULN yielded the highest accuracy for predicting malignant lesions with a sensitivity of 73.0%and a specificity of 68.5%,and the AUC was 0.700(95%CI 0.593?0.807).A sensitivity of 68.8%and a specificity of 53.3%was achieved in the cut-off PRL value of 1.27×ULN suggested by previous researchers.In sensitivity analysis,the best cut-off to differentiate malignant lesions from benign ones was 1.152×ULN(sensitivity 67.2%,specificity 81.6%),and the AUC was 0.744(95%CI 0.647?0.841).Conclusion:Using PRL to distinguish between malignant and benign pituitary stalk thickening was unsatisfactory,which tended to predict benign lesions as malignant lesions.PART 2:The overweight/obesity and dyslipidemia in patients with intracranial germ cell tumorsObjective:Metabolic disorders are prevalent in brain tumor survivors.The study aimed to evaluate the prevalence of overweight/obesity and dyslipidemia in patients with intracranial germ cell tumor(iGCT),and to explore the risk factors of it.Method:iGCT patients visiting Peking Union Medical College Hospital between Jan 2008 to Oct 2020 were included,and relevant clinical data was retrospectively collected.The incidence of overweight/obesity and dyslipidemia during visits was calculated.Mixed effect model was used to evaluate the relationship between body mass index(BMI)standardized deviation score(SDS),overweight/obesity,blood fat levels,and dyslipidemia and potential risk factors including lesion locations,treatment(surgery,chemotherapy,radiotherapy),hypopituitarism,and hormone replacement.Results:Six hundred and twenty-five records from 106 patients were included in analysis.The median follow-up time was 27(IQR 5?59)months.Forty-nine(46.2%)patients were diagnosed with overweight/obesity during visits.Treatment,glucocorticoid supplementation was significantly related to increased BMI-SDS and risk of overweight/obesity,while sex hormone replacement was related to decreased BMI-SDS and risk of overweight/obesity.Eighty-six(81.1%)patients were diagnosed with dyslipidemia during visits.The incidence of hypercholesterolemia,hypertriglyceridemia,hypo high density lipoprotein(HDL)cholesterolemia,hyper low density lipoprotein(LDL)cholesterolemia was 64.2%,58.5%.45.3%.53.8%,respectively.There was a significant relationship between hypothalamus involvement and dyslipidemia.Treatment was related to a higher risk of hypercholesterolemia.Hypertriglyceridemia was found to be associated with hypothyroidism.Hypo HDL cholesterolemia was found to be associated with treatment,adrenal insufficiency,hypothyroidism,and hypogonadism.In patients with growth hormone,sex hormone replacement,a lower level of total cholesterol,and low density lipoprotein cholesterol was observed.And sex hormone replacement was significantly related to a lower risk of hypercholesterolemia and hypertriglyceridemia.Conclusion:Overweight/obesity and dyslipidemia was high prevalent in iGCT patients.Hypothalamus involvement and treatment were risk factors of metabolic disorders.Glucocorticoid supplementation might deteriorate these disorders,while other hormone replacement therapy might improve patients' metabolism.