Endocrine Abstracts

Background: Aggressive pituitary adenomas (APAs) take place phenotypically between benign pituitary adenomas and pituitary carcinomas with systemic metastasis. Frequent recurrence and resistance to conventional treatments are characteristic features of APAs in their clinical course. Temozolomide is an alkylating agent that has been used in the treatment of pituitary carcinomas and APAs since 2006. Herein, we report a patient who received temozolomide treatment due to APA.

Case presentation: A 57-year-old male patient with complaints of headache and visual impairment had been admitted to state hospital in 1991. Laboratory and imaging studies had revealed nonfunctioning invasive pituitary macroadenoma, and he had underwent transcranial operation. The patient had developed pituitary insufficiency after operation; therefore replacement therapy had been started. Thirty radiotherapy (RT) sessions had been performed due to the lack of complete resection of the mass. Then, he was referred to our department. He was reoperated in 2006 and 2009. In magnetic resonance imaging (MRI) after surgeries, a macroadenoma (37×35×30 mm in size) was observed and follow-up was planned because of its size to remain stable. In 2012, MRI revealed that the mass grown in size (50×40×38 mm). It filled suprasellar cistern and sphenoidal sinus, and infiltrated cavernous sinuses. After six cycles of temozolomide were given with 30 conventional RT sessions, minimal reduction in mass size was observed. Six more cycles of temozolomide was given. After treatment, the mass was measured as 40×38×28 mm. The patient’s monitoring still continues with stable disease.

Discussion: In our case, minimal shrinkage and stabilization of the mass size were achieved after temozolomide treatment. According to the case reports published in the literature, the effectiveness of temozolomide in APAs is about 55%, although interpretation of efficacy criteria differs in various publications. However, large-scale studies are needed to determine the indications, proper doses and duration of temozolomide treatment.