Endocrine Abstracts

Introduction: Only one case of hypophysitis secondary to Takayasu’s artheritis (TKA) has been described so far. We report the second case of a TKA presenting with a massive sellar and cerebrovascular infiltration.

Clinical case: A 52 years-old female was referred to endocrine outpatient clinics after a brain MRI performed for a 2-year history of headaches, dizziness and general discomfort. Past medical history included hypertension and aspecific sympthoms (fatigue, nausea, loss of libido). Pituitary MRI found a 13 mm sellar tumor-like lesion extending to the optic chiasm with homogenous gadolinium uptake, pituitary stalk thickening and ectopic neurohypophysis; parasellar T2 dark sign was suggestive for an infiltrating process of the cavernous sinus. Brain angio-RMN revealed sub-occlusion of the intracranial and extracranial trait of the left carotid artery with compensation circles and a stenotic intracranial trait of the right carotid artery. Visual field examination resulted in bitemporal hemianopsias. Endocrine work-up revealed panhypopituitarism with mild hyperpolactinemia, probably secondary to deafferentation. Diabetes insipidus was inferred by low urine osmolarity (290 Osm/kg), but requiring revaluation after glucocorticoids replacement. Adrenal and thyroid function were promptly replaced with sudden recovery of fatigue and nausea. Even in the absence of systemic inflammatory symptoms nor increased inflammatory reactants, screening for possible causes of secondary hypophysitis was undertaken. Serum IgG4 levels, serum and liquor angiotensing converting enzyme levels, serum quantiferon testing and liquor culture, ANCA antibodies were all negative. Doppler ultrasound of carotid arteries revealed possible signs of left carotid dissection but no signs of temporal arteries involvement. Hence, evidence of mild stenosis of coeliac and upper mesenteric artery and left common femoral artery on angio-CT together with a mild uptake in the thoracic and abdominal aorta on 18-FDG PET led to the diagnosis of TKA. Immunosuppressive therapy with high doses of methylprednisolone (1 g bolus e.v. for 3 consecutive days) followed by a down-tapering scheme from 50 mg/day prednisone p.o. was undertaken, then shifted to cortone acetate at replacement doses over one year. Follow-up radiological investigations at 6-12 months showed a marked reduction of pituitary infiltrate and up-take of thoracic/abdominal aorta but an unchanged intracranial artery stenosis. Concomitantly, endocrine follow-up revealed a normalization of prolactin levels and gonadotrope/thyrotrope axis, which allowed the discontinuation of levothyroxine replacement therapy.

Conclusion: Pituitary gland and hypothalamus are very unusual yet possible sites of TKA infiltration. Massive sellar infiltration allowed diagnosis of systemic vasculitis even without inflammatory manifestations, reasonably reducing diagnostic delay and fatal consequences.