Endocrine Abstracts

Introduction: Granulomatosis with polyangiitis (GPA) is an anti-neutrophil cytoplasmic antibody (ANCA)-associated systemic vasculitis of both small and medium-sized vessels. Pituitary involvement in GPA is uncommon and few cases have been previously reported. Isolated pituitary involvement in GPA is rare and 96% of cases are associated with other organ involvement. GPA commonly affects the upper respiratory tract (93%), lungs (73%) and kidneys (67%).

Case: A 46-year-old male was admitted for investigation of vision changes. He had a 2–3-month history of blurred vision, headaches (retro-orbital discomfort), left eye redness, arthralgia, and epistaxis. His visual acuity was 6/60 with a central scotoma. A pituitary MRI revealed a likely inflammatory mass, involving the hypothalamus and infundibulum, suggestive of hypophysitis. Whilst an inpatient, he was diagnosed with diabetes insipidus and hypopituitarism. His blood test showed FSH 1.0 iu/l, LH <0.2 iu/l, Testosterone <0.4 nmol/l, TSH 0.03 mu/l, FT4 7.4 pmol/l, Prolactin 83 miU/l, random Cortisol 323 nmol/l and a normal short Synacthen test. An ear, nose, and throat opinion was sought due to the recurrent epistaxis. A nasal biopsy was taken with histology diagnostic of GPA. This was backed by positive ANCA and an elevated ESR (79 mm/hr). He was treated with high-dose steroids and cyclophosphamide. This rapidly and remarkably relieved his symptoms. His visual acuity, central scotoma, and red eye improved. His ESR normalised and a repeat pituitary MRI revealed substantial resolution of the mass. He was commenced on hormonal replacement (thyroxine and testosterone).

Discussion: GPA is a multi-system disorder characterised by necrotising granulomatous small-vessel vasculitis. GPA mainly affects a combination of the ear, nose, and throat. However, it may also affect the joints, skin, eyes, and other organs. GPA occurs in equal proportions between men and women. Although, in the few previously reported cases with pituitary involvement, there were more female patients. The time of pituitary symptom onset in 13(56%) of previous reported cases occurred between 2 months and 15 years after receiving a diagnosis of GPA. The prevalence of central nervous system involvement ranges from 15% to 54%. The most common neurological manifestation is peripheral neuropathy due to small vessel vasculitis (10-28%).

Conclusion: GPA is a rare cause of pituitary failure and should be considered in the differential diagnosis of hypophysitis. Multisystemic presenting symptoms, such as those demonstrated in this case, should alert clinicians to the possibility of pituitary involvement. This is likely to be as part of a multisystemic disease process since isolated pituitary involvement is rare.