A case of apoplectic lymphocytic hypophysitis complicated by polymyalgia rheumatica

[Oculomotor nerve compression on MRI in a 56-year-old man with pituitary apoplexy due to panhypophisitis]

A 56-year-old man noted sudden onset of headache, fever, right pupil-spared oculomotor nerve palsy and consciousness disturbance. Swelling of pituitary with T₁ high intensity on brain MRI suggested the diagnosis of pituitary apoplexy. Considering significant decrease of pituitary anterior lobe hormone and central diabetes insipidus, high dose of hydrocortisone was administered. Eight days after onset, consciousness level and headache improved. On day 30, brain MRI revealed the reduction of mass size, and on day 46, photophobia and double vision disappeared. Following the rapid response to steroid and disappearance of pituitary lesion, pituitary apoplexy was probably caused by panhypophisitis. Thin-slice brain MRI confirmed the compression of oculomotor nerve at inlet zone of cavernous sinus, suggesting the mechanism of oculomotor palsy was perfusion impairment of feeding artery.

From pituitary expansion to empty sella: disease progression in a mouse model of autoimmune hypophysitis

Lymphocytic hypophysitis has a variable clinical course, where a swelling of the pituitary gland at presentation is thought to be followed by pituitary atrophy and empty sella. Data in patients, however, are scanty and contradictory. To better define the course of hypophysitis, we used an experimental model based on the injection of pituitary proteins into SJL mice. A cohort of 33 mice was divided into three groups: 18 cases were immunized with pituitary proteins emulsified in complete Freund's adjuvant; six controls were injected with adjuvant only; and nine controls were left untreated. Mice were followed by cranial magnetic resonance imaging (MRI) for up to 300 d, for a total of 106 MRI scans, and killed at different time points to correlate radiological and pathological findings. Empty sella was defined as a reduction in pituitary volume greater than 2 sd below the mean volume. All immunized mice showed by MRI a significant expansion of pituitary volume during the early phases of the disease. The volume then decreased gradually in the majority of cases (14 of 18, 78%), reaching empty sella values by d 300 after immunization. In a minority of cases (four of 18, 22%), the decrease was so rapid and marked to induce a central area of necrosis accompanied by hemorrhages, mimicking the condition known in patients as pituitary apoplexy. No radiological or pathological changes were observed in controls. Overall, these findings indicate that the evolution of hypophysitis is complex but can lead, through different routes, to the development of empty sella.