Background:Pituitary stalk thickening (PST) used as an imaging diagnosis plays a major role in diagnosis and treatment of the hypothalamus and pituitary disease at an early stage.Up until now,several lines of systematic investigations have been conducted among adolescents,and the results indicated that PST is possibly one of the principal early manifestations of sellar region tumor.To characterize the major clinical features of PST and to identify the most effective treatments we conducted this study.Methods:This was a retrospective review of patients with PST evaluated at Huashan Hospital over an eight-year period between 2007 and 2014.One hundred fifty nine patients who were diagnosed PST were included.The data including demographics,clinical presentations,imaging examinations,laboratory results and surgery were thoroughly reviewed and carefully analyzed.According to their clinical presentations and examinations,relevant treatments were adopted and different prognosis were observed.Results:Of the 159 patients,57 were males and 102 were females (median age was 29 and 43.4％ were under the age of 21 years).And of the patients in the age group between 30 and 35 years,84％ were females.Polydipsia and polyuria was the most common clinical manifestation observed in 90 cases (＞50％).49.5％ of the patients were diagnosed to have at least one anterior pituitary dysfunction.The sellar region MRI (SR-MRI) data showed that patients who had different clinical presentations or pituitary function showed different SR-MRI appearance.Over 60％ patients who performed followup MRI showed shrunken PST.Fourteen cases who received radiotherapy appeared to be improved as shown by MRI.Conclusions:PST is most commonly seen in the teenagers and the women of reproductive age.Distinct etiology may be identified based on the clinical manifestations,age and SR-MRI,which would help to make the final decision for treatments.Radiotherapy and immuno-suppressed therapy are effective in alleviating clinical symptoms and shrinking the stalk thickening.