Background: Pituitary carcinoma is very rare and hard to diagnose. However, some atypical pituitary adenomas present with a high rate of proliferation and extensive invasion, suggesting a tumor with a high degree of malignancy. Case presentation: Here, we present a case study of this type of tumor. A 46 years old women was admitted for headaches and impaired vision, and MRI and CT revealed a sellar lesion. She underwent a transsphenoidal surgery followed by radiotherapy, but the tumor recurred only one month later. She decided to undergo a second and third operation. The final pathology showed a non-functioning adenoma that was approximately 80% ki-67-positive and extensively p53-positive. No metastasis was found. The tumor progressed extremely quickly, and the patient died 7 months after the initial diagnosis. Conclusions: A pituitary adenoma like this should be treated like a carcinoma, and early treatment may increase the likelihood of survival. A traditional diagnosis standard is unfit for this type of tumor.