Aggressive Pituitary Adenomas: The Dark Side of the Moon

Although pituitary adenomas are considered benign lesions, a small group may show clinically aggressive behavior, sometimes independently from the classic markers of aggressiveness, including the Ki67 labeling index or p53 expression.

We selected 7 patients harboring a pituitary tumor with clinical features of aggressiveness. Patients underwent a full preoperative and postoperative endocrinologic and neuroradiologic workup. Two were nonfunctioning, 2 prolactin-secreting, 2 adrenocorticotrophic hormone-secreting, and 1 a growth hormone-secreting adenoma.

The 7 patients underwent a total of 17 surgical procedures. At the first surgical procedure, gross total removal was achieved in none of the patients, whereas subtotal removal (>90% of tumor removed) was achieved in 4/7 cases and partial removal (<90% of tumor removed) in 3/7 cases. At first operation, 4/7 patients showed a Ki67 index ≤3% and 2/7 >3%; this information was not available for 1 patient. Postoperatively, all patients underwent radiation therapy. Three patients received chemotherapy with temozolomide. Three patients underwent peptide receptor radionuclide therapy. To date, 1 patient has died of tumor progression, and 2 patients are in a poor general condition. The remaining 4 patients are in a fair/good condition, without any major complaints. The mean follow-up is 43.42 months.

Aggressive pituitary adenomas represent a specific and still underestimated entity, often diagnosed late. Clinical and neuroradiologic rapid progression is often the only marker of aggressiveness. Surgical debulking remains the first therapeutic option. Multidisciplinary management is mandatory to offer these patients targeted therapeutic options.