Presentation
Headache, fatigue, and lethargy. Her laboratory work-up revealed reduced prolactin, ACTH, and TSH and normal levels of FSH and LH. The patient didn't suffer any systemic disease.
Patient Data
- bulky pituitary gland showing homogenous enhancement with no focal lesions
- thickened pituitary infundibulum
- dural tail sign is noted
- an absent posterior pituitary high signal at T1 WI
- parasellar dark T2 dark signal encasing the pituitary gland showing post-contrast enhancement (less than the pituitary enhancement)
- bulky pituitary gland showing homogenous enhancement with no focal lesions
- an absent posterior pituitary high signal at T1 WI (blue arrow)
- dural tail sign is noted (green arrow)
- thickened pituitary infundibulum (pink arrow)
- parasellar T2 dark signal encasing the pituitary gland showing post-contrast enhancement (less than the pituitary enhancement) (Yellow arrows)
Case Discussion
The patient didn't suffer any systemic disease and showed a dramatic improvement after corticosteroid treatment.
Diagnosis is presumptive depending on the clinical, laboratory, and radiographic features.
This case shows several radiographic features of lymphocytic hyophysitis such as a bulky pituitary gland showing homogenous enhancement with absent focal lesions, the absent posterior pituitary bright signal on non-contrast T1WI, and thickened enhancing pituitary stalk infundibulum, as well as the characteristic para-sellar T2 dark signal.
Y.Nakata et al hypothesized that areas of T2 dark-signal intensity around the pituitary gland and in the cavernous sinus were characteristic in patients with lymphocytic hypophysitis and were useful for distinguishing lymphocytic hypophysitis from pituitary adenomas 1.
Parasellar T2 dark signal could be also be seen in the following diseases: