Peritumoral cysts associated with pituitary macroadenoma

Abstract

OBJECT Peritumoral cysts are benign nonneoplastic cysts that are found adjacent to extraaxial brain tumors such as meningiomas, schwannomas, craniopharyngiomas, and esthesioneuroblastomas. Peritumoral cysts associated with pituitary macroadenomas have not been previously described in the literature. The authors report 6 cases of giant macroadenoma-associated peritumoral cysts and delineate their imaging spectrum. METHODS The authors retrospectively reviewed the records of 179 patients diagnosed with pituitary macroadenomas who underwent tumor resection at their institution and had preoperative MRI scans available for review. The patients were evaluated for the presence of associated peritumoral cysts. Clinical presentation, histopathology, follow-up time, tumor and peritumoral cyst dimensions were recorded. Signal intensity on T1-weighted, T2-weighted, diffusion-weighted, and FLAIR sequences, as well as pre- and postcontrast appearance, were determined. RESULTS Six patients (3.4%) with associated peritumoral cysts were identified in our cohort of 179 patients with pituitary macroadenoma. Twelve patients in the cohort had giant macroadenomas (≥ 4.0 cm), and 50% of these tumors had associated peritumoral cysts with significant extrasellar extension of the macroadenoma. Only tumors with craniocaudal, transverse, and anteroposterior diameters of 3.6 × 3.4 × 4.2 cm to 7.0 × 7.4 × 6.8 cm (mean 5.3 × 5.1 × 5.6 cm), respectively, had associated peritumoral cysts. The growth pattern in all tumors was suprasellar, with predominant anterior and lateral extension. Cysts showed T1-weighted, T2-weighted, and FLAIR hyperintensity in 67%, 67%, and 60% of patients, respectively. There was no contrast enhancement of the cyst wall or fluid contents in any patient. Postoperatively, cysts had completely resolved (4 of 5) or significantly decreased in size (1 of 5). One patient was lost to follow-up. CONCLUSIONS Macroadenoma-associated peritumoral cysts are rare, benign, and likely nonneoplastic fluid collections that do not represent neoplasm. These cysts display a predictable pattern of hyperintensity on T1-weighted, T2-weighted, and FLAIR sequences and do not enhance. They most likely represent proteinaceous CSF in a sulcus or cistern that becomes trapped (encysted) by anterolateral extension of unusually large macroadenomas. Peritumoral cysts may facilitate resection of the associated macroadenoma by providing a cleavage plane.

Outcomes and surgical nuances in management of giant pituitary adenomas: a review of 108 cases in the endoscopic era

“…Occasionally, the surgeon may encounter a peritumoral cyst associated with a giant pituitary macroadenoma. 35 These are benign, nonneoplastic fluid collections that likely represent proteinaceous CSF that has been trapped in a sulcus or cistern by anterolateral extension of the giant tumor. These cysts can be used by surgeons to facilitate dissection by providing a cleavage plane, and the resection of cysts is likely unnecessary (case 3).…”

“…These cysts can be used by surgeons to facilitate dissection by providing a cleavage plane, and the resection of cysts is likely unnecessary (case 3). 35 Despite the evidence for better outcome rates with regard to morbidity and visual outcomes with transsphenoidal surgery, the surgeon should keep in mind the limitations of visualization at surgical access to portions extending laterally beyond the carotid arteries. 1,2,7,13,23 Whereas traditional transsphenoidal microscopic techniques have the limitation of a longer working distance and distant illumination through the narrow corridor provided by the Hardy retractor, the use of the endoscope as an adjunct or on its own may provide optimal visualization of the tumor and increase the safety of the surgery.…”

Diagnostic Value of Fluid-Attenuated Inversion Recovery Magnetic Resonance Imaging for Multilocular Ameloblastoma

“…Fluid signal suppression could help increase the contrast between cystic and solid portions. Some studies have reported that FLAIR improved tissue contrast in the presence of degenerative disease of the cervical spine area and brain lesions [10][11][12] . It has also been reported that there is a potential use for FLAIR imaging in patients with vascular malformations and to assess condylar bone marrow changes in temporomandibular joint disorders 14,15) .…”

“…Fluid-attenuated inversion recovery (FLAIR) imaging is an inversion recovery technique that suppresses the signal of pure water by setting the inversion time to the time at which the magnetization of pure water equals zero. FLAIR, an MRI sequence, has important roles in brain imaging [10][11][12] and has recently been used to examine pathological areas in the eye 13) . There are few reports, however, of the potential use of FLAIR in the oral and maxillofacial region 14,15) .…”