Analysis Of Clinical Characteristics In Patients With Pituitary Stalk Thickening And Exploration Of A Differential Diagnostic Model

PURPOSE: To summarize the clinical features of patients with pituitary stalk thickening,analyze the related factors of hypopituitarism,and develop a diagnostic model in order to differentiate related neoplastic and inflammatory diseases,thus to assist clinical diagnosis and treatment.PATIENTS AND METHODS: 1.A total of 261 PST patients hospitalized in our clinical center from January 1,2012 to December 31,2016 were retrospectively studied.Clinical data were collected.The demographics characteristics,clinical symptoms,endocrine function alteration,and MRI features were generalized,and the related factors of hypopituitarism were analyzed.2.A total of 70 patients with PST-related neoplastic and inflammatory diseases diagnosed according to their pathological findings from January 1,2012 to February 28,2018 were reviewed,including a data training set of 40 cases,a validation set of 12 cases and a test set of 18 cases.Data mining software was used to screen out important clinical parameters.Based on the training set data,the aforementioned clinical parameters were used for developing a differential diagnostic model and the validation and test set were applied to examine the classification ability.RESULTS: 1.Of all the 261 patients,64.7% were females,the male to female ratio was 1:1.84.The median age at onset was 30.0 years(range,14.0-45.7 years)overall and the median course of disease was 2.0(0.3-6.0)years.The age distribution of male subgroup showed obviously two “peaks” in 6-18 years and 42-48 years,while in female patients,it was relatively equally distributed during the fertile period.2.Polydipsia and polyuria was the most common major presenting symptom.Suspicious pituitary mass or mass effect related manifestations mainly occurred in adult-onset patients,while most of the young patients(<18 years)began with the symptoms of growth or puberty disorder.3.47.5% patients had at least one anterior pituitary dysfunction or central diabetes insipidus.Secondary hypogonadism was the most common APD,followed by growth hormone deficit,adrenal insufficiency and thyroid dysfunction.38.5% patients had hyperprolactinemia.More than half of the 47 patients had CDI combined with APD.4.The increase in the width of the pituitary stalk was associated with higher risk of CDI and CDI together with APD(OR=3.57,P<0.001;OR=2.28,P=0.029),and was a factor to estimate the aforesaid functional decline(PSW: 4.15 mm,sensitivity 0.81,specificity 0.79;PSW: 4.75 mm,sensitivity 0.69,specificity 0.71).However,its significance for reflecting hypopituitarism was very limited.5.From January 1,2012 to February 28,2018,a total of 70 patients(21.5%)were diagnosed based on their pathological findings,including 57 cases(81.4%)of neoplastic diseases and 13 cases(18.6%)of inflammatory diseases.The incidence of pituitary dysfunction was higher(P=0.004)and pituitary stalks were thicker(P<0.001)in the inflammatory subgroup.6.Based on the comprehensive consideration of information gain ranking and easiness of clinical data access,six indicators including the presence of CDI,patterns of PS thickening,pituitary stalk width,neutrophilic granulocyte percentage,serum sodium level and gender were further selected to compose an equation classifier as follows: The validation and test data indicated that the differential diagnostic model had favorable etiological classification ability.CONCLUSION: Pituitary stalk thickening is more common in adolescents,women of fertile period and some of the middle-aged males.Its main clinical manifestations include two aspects: occupying lesions or mass effect related symptoms and endocrine function alteration related symptoms.Juvenile-onset patients are more likely to present endocrine changes.Patients with thickened pituitary stalks are often accompanied by varying degrees of hypopituitarism,and the pituitary stalk width can,to a certain extent,indicate the presence of CDI,and whether it is further combined with APD.However,its role in reflecting anterior pituitary hypofunction was very limited,so that the significance of comprehensive endocrine assessment should be emphasized.The two major causes of pituitary stalk thickening are neoplastic and inflammatory diseases.A differential diagnostic model established based on several clinical indicators can effectively classify these two etiologies and has certain potential clinical application value.