Not All Sellar Lesions Are Adenomas!

Introduction: Pituitary adenomas are the most common sellar lesions, accounting for up to 90% of all sellar pathologies. There is a broad differential for the remaining 10%, ranging from congenital to neoplastic, infectious, and vascular etiologies. Imaging along with clinical and endocrinological evaluation is often needed to develop the correct diagnosis, which then dictates the management and surgical approach if indicated.

Objective: Sellar lesions on imaging are commonly pituitary adenomas. Differential diagnoses of sellar lesions are often overlooked and depending on the diagnosis, surgical intervention may or may not be needed. The purpose of this abstract is to review the regional anatomy of the sella turcica, imaging characteristics of different pathologies, and widen the differential diagnosis of sellar lesions.

Methods: A retrospective search was performed of the radiology database for studies using an institutional-wide radiology report search engine, yielding studies imaging the sella. Both CT and MRI images, as well as clinical documents were reviewed.

Results: MRI is the gold standard for the sellar and parasellar region. For detailed evaluation of hypothalamic anatomy, sagittal and coronal spin-echo T1-weighted sequences can be performed with thin sections (£ 2–3 mm) and a small field of view (16–20 cm). The same sequence can be obtained after the administration of the intravenous gadolinium contrast). CT may be useful in evaluating the bony structures and detecting the presence of calcifications in tumors and vasculature. Characteristics of imaging and anatomic approach may help in establishing a differential diagnosis, which then dictates management. Real-world examples seen within the database were used as examples to demonstrate that not all sellar lesions are in fact pituitary adenomas.

Conclusion: A variety of sellar lesions may mimic pituitary adenomas. It is crucial to be aware of the differential diagnosis of the sellar lesions (neoplastic, infectious, developmental, and/or vascular), as the ultimate diagnosis may alter the management of the patient ([Fig. 1]).

Fig. 1 Sagittal T1 (top left) showing an expansile sellar lesion with intrinsic T1 hyperintensity. Axial T2 (top right) showing a small T2 hypointense nodule (arrow) within the expansile T2 intense cystic sellar lesion, pathognomonic of a Rathke cleft cyst. Sagittal (bottom left) and coronal (bottom right) T1 Post demonstrating peripherally enhancing tissue, consistent with the normally enhancing compressed pituitary gland.

Publikationsverlauf

Artikel online veröffentlicht:
15. Februar 2022