Lymphocytic adenohypophysitis: skull radiographs and MRI

Abstract

We report the skull radiograph, CT and MRI findings in three patients with lymphocytic adenohypophysitis mimicking pituitary adenoma. All cases were associated with pregnancy. CT demonstrated a pituitary mass but did not differentiate lymphocytic adenohypophysitis from pituitary adenoma. The skull radiographs showed either a normal sella turcica or minimal abnormalities; they did not show ballooning or destruction. The MRI appearances were distinctive: relatively low signal on T1-weighted images; preservation of the bright posterior pituitary lobe despite the presence of a relatively large pituitary mass, less common in macroadenomas; marked contrast enhancement compared with pituitary macroadenomas; and dural enhancement adjacent to a pituitary mass.

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

“…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.…”

Lymphocytic hypophysitis

“…Radiographically, it can be differentiated from pituitary adenoma as shown in the table. [7][8][9][10] Lymphocytic hypophysitis can be confused with macroadenoma as mentioned above, and also with gestational hypopituitarism, Figure 3. Lymphocytic Hypophysitis.…”

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

“…20 In addition, macroadenomas appear heterogeneous both before and after contrast medium administration, in direct relationship to their size, though heterogeneity can also occur in AH. [21][22][23] Overall, no single radiologic sign has sufficient accuracy to distinguish with certainty AH from pituitary adenomas. The aim of this study, therefore, was to develop a diagnostic scoring system from a wide range of clinical and MR imaging features to increase the probability of diagnosing AH before surgery.…”