Outcome of giant pituitary tumors requiring surgery

Abstract

Objective: The management of giant pituitary tumors is complex, with few publications and recommendations. Consequently, patient's care mainly relies on clinical experience. We report here a first large series of patients with giant pituitary tumors managed by a multidisciplinary expert team, focusing on treatments and outcome.

Methods: A retrospective cohort study was conducted. Giant pituitary tumors were defined by a main diameter > 40mm. Macroprolactinomas sensitive to dopamine agonists were excluded. All patients were operated by a single neurosurgical team. After surgery, multimodal management was proposed, including hormone replacement, radiotherapy and anti-tumor medical therapies. Outcome was modeled using Kaplan-Meyer representation. A logistic regression model was built to identify the risk factors associated with surgical complications.

Results: 63 consecutive patients presented a giant adenoma, most often with visual defects. Patients were operated once, twice or three times in 59%, 40% and 1% of cases respectively, mainly through endoscopic endonasal approach. Giant adenomas included gonadotroph, corticotroph, somatotroph, lactotroph and mixed GH-PRL subtypes in 67%, 14%, 11%, 6% and 2% of patients respectively. Vision improved in 89% of patients with prior visual defects. Severe surgical complications occurred in 11% of patients, mainly for tumors > 50 mm requiring microscopic transcranial approach. Additional radiotherapy was needed for 29% of patients, 3 to 56 months after first surgery. For 6% of patients, Temozolomide treatment was required, 19 to 66 months after first surgery.

Conclusions: Giant pituitary tumors require multimodal management, with a central role of surgery. Most often, tumor control can be achieved by expert multidisciplinary teams.

Keywords: adenoma; aggressiveness; complication; giant pituitary tumor; radiotherapy; surgery.

Figure 1

Different patterns of giant tumors extension Preoperative pituitary MRI are presented, including gadolinium-enhanced T1 weighted sagittal (A, B), coronal (C–E) and T2 weighted coronal (F) images. (A) subfrontal extension (white arrow); (B) posterior fossa extension (white arrow); (C) suprasellar extension with a “narrow neck” aspect between the intrasellar and the suprasellar tumor components; (D) encasement of the right anterior cerebral artery (white arrow); (E) massive invasive sphenoid tumor bridging the two cavernous sinuses, defined as “sphenoid arch” aspect (white dotted rectangle); (F) tumor extension through the roof-top of the right cavernous sinus (white arrow).

Figure 2

Surgical resection of giant pituitary tumors Pituitary MRI from three patients are presented, before and after surgery (gadolinium-enhanced T1 weighted coronal and sagittal images). (A-D) Giant pituitary tumor with a “narrow neck” pattern, resected with an extended endoscopic endonasal approach. (E-H) Giant pituitary tumor with transdiaphragmatic subfrontal extension, resected in two steps with combined endoscopic endonasal and microscopic transcranial approaches. (I-L) Giant pituitary tumor with a huge suprasellar expansion extending beyond the Monro foramen, resected with a transfrontal transcranial approach.

Figure 3

Cumulative incidence of patients requiring radiotherapy after surgery (Kaplan-Meyer representation).

Figure 4

Cumulative incidence of patients requiring chemotherapy after surgery (Kaplan–Meyer representation).