[Two Cases of Hypovascular Pituitary Metastases and Literature Review].

Pituitary metastasis,a rare kind of intracranial malignant tumor,is characterized by metastasis from all parts of the body to the pituitary.The common tumors metastatic to pituitary are abundant with blood supply,located in the posterior pituitary lobe and/or the pituitary stalk.The lesion shows infiltrative growth,and mainly demonstrates low signal on T1 weighted imaging and high signal on T2 weighted imaging.It is usually enhanced significantly after iodinated contrast administration.The metastatic tumor with poor blood supply is similar to pituitary macroadenoma on magnetic resonance image,which makes it difficult to be differentiated.We reported two cases of pathologically diagnosed pituitary metastasis with poor blood supply and reviewed related papers,aiming to provide the imaging differentiation points of hypovascular pituitary metastasis.