A Radiologic Score to Distinguish Autoimmune Hypophysitis from Nonsecreting Pituitary Adenoma Preoperatively

Abstract

BACKGROUND AND PURPOSE:Autoimmune hypophysitis (AH) mimics the more common nonsecreting pituitary adenomas and can be diagnosed with certainty only histologically. Approximately 40% of patients with AH are still misdiagnosed as having pituitary macroadenoma and undergo unnecessary surgery. MR imaging is currently the best noninvasive diagnostic tool to differentiate AH from nonsecreting adenomas, though no single radiologic sign is diagnostically accurate. The purpose of this study was to develop a scoring system that summarizes numerous MR imaging signs to increase the probability of diagnosing AH before surgery.

Parasellar T2 Dark Sign on MR Imaging in Patients with Lymphocytic Hypophysitis

“…Gutenberg et al 14 reported that these findings contributed significantly to classifying the outcome as pituitary adenoma or autoimmune hypophysitis (including lymphocytic and granulomatous hypophysitis), and our results were consistent with their findings. 14 Although MR imaging findings such as loss of PPHI, thickened stalk, pituitary symmetry, and homogeneous enhancement showed significant difference in the statistical analysis in the present study, these findings were nonspecific and were observed in both diseases. Loss of PPHI was observed in central diabetes insipidus due to idiopathic, inflammatory, or neoplastic processes, including pituitary adenoma.…”

“…Some previous studies reported that loss of PPHI, thickened stalk, pituitary symmetry, homogeneous enhancement, and the dural tail were useful for distinguishing LYH from pituitary adenomas, 2,3,8,[11][12][13][14] but only 1 previous study investigated this statistically. Gutenberg et al 14 reported that these findings contributed significantly to classifying the outcome as pituitary adenoma or autoimmune hypophysitis (including lymphocytic and granulomatous hypophysitis), and our results were consistent with their findings.…”

“…In several recent articles, some findings were reported to be useful for distinguishing pituitary adenoma from LYH, such as precontrast homogeneous signal intensity, intact sellar floor, suprasellar extension, loss of PPHI, stalk thickening, mass symmetry, homogeneous enhancement, and adjacent dural enhancement (the so-called dural tail). 2,3,8,[11][12][13][14] In this study, evaluation of the precontrast signal intensity was excluded because pituitary adenomas often show complicated signal intensities due to hemorrhagic or cystic changes, and it is a not suitable factor for making a simple assessment. The findings of destruction of the sellar floor and extension to the sphenoid sinus were also excluded because it was obvious that these findings indicate neoplasm.…”

“…MR imaging findings in patients with LYH and pituitary adenoma were reported in some recent articles. 2,3,8,[11][12][13][14] However, most previous reports of MR imaging findings of LYH were case reports and/or reviews of the literature.…”

Autoimmune hypophysitis: a study of natural course

“…16 All patients diagnosed with autoimmune hypophysitis were followed every three monthly with evaluation for pituitary functions and six monthly with gadolinium enhanced MRI of pituitary. At diagnosis all patients were evaluated with automated perimetry; if found abnormal automated perimetry was repeated every month till normalisation of visual fields.…”