E-Poster Presentation ESA-SRB-ANZBMS 2021

A long awaited diagnosis (#432)

Jovitta William 1 , Jason Galanos 2 , Kimberly Cukier 1 , Natalie Harrision 1 , Penny McKelvie 3
  1. Endocrinology, Geelong endocrinology and diabetes, Geelong, VIC, Australia
  2. Endocrinology, Melbourne Endocrinology , Melbourne, Victoria, Australia
  3. Anatomical Pathology, St Vincent’s Hospital, Melbourne , Victoria , Australia

We present the case of MR AB, a 30-year-old male, referred in August 2020 with central hypogonadism and a 10-year history of polydipsia and polyuria with an overnight water-deprivation test consistent with diabetes insipidus. His remaining pituitary profile was unaffected, and he was found to have pituitary stalk abnormalities on MRI. Following limited biochemical and radiological response to a steroid-course, he underwent a pituitary-stalk biopsy with histopathology consistent with IgG4 related hypophysitis (IgG4-RH). At present, no extra-pituitary manifestations of IgG4 related disease has been demonstrated, and he remains clinically well on GnRH analogue and desmopressin therapy.

IgG4-RH is diagnosed upon meeting criteria as described Leporati et al.(1). Given increasing recognition of its poorly specific nature, the need for a set of diagnostic criteria that can better differentiate between true IgG4-RH vs other pituitary autoimmune and inflammatory entities (which also meet Leporati’s biopsy criteria) has arisen (2,3).

In this clinical case study, we will review the strengths and pitfalls of our current diagnostic pathway for the diagnosis of IgG4-RH. We will describe the emergency of two distinct clinical phenotypes of IgG4-RH, which, while sharing many biochemical, radiological and histopathological findings, may either represent two distinct pathologies or part of a spectrum of the same disease process.

TAKE HOME POINTS

  • IgG4 RH is a relatively new entity, likely underdiagnosed, and can present with a normal serum IgG4 level.
  • With prompt identification and treatment with glucocorticoid/immunosuppressive therapy there is generally an excellent response to treatment
  • While biopsy has historically been the gold standard for diagnosis, there are cases of non-IgG4 related disease fulfilling criteria for IgG4-RH.
  • Similarly, when diagnosing IgG4-RD based on an abnormal MRI appearance and elevated serum IgG4, one must keep in mind alternate causes for these changes
  1. Leporati P, Landek-Salgado MA, Lupi I, Chiovato L, Caturegli P. IgG4-related hypophysitis: a new addition to the hypophysitis spectrum. J Clin Endocrinol Metab. 2011 Jul;96(7):1971-80. doi: 10.1210/jc.2010-2970. Epub 2011 May 18. PMID: 21593109; PMCID: PMC3135201.
  2. 2. Shikuma J, Kan K, Ito R, Hara K, Sakai H, Miwa T, Kanazawa A, Odawara M. Critical review of IgG4-related hypophysitis. Pituitary. 2017 Apr;20(2):282-291. doi: 10.1007/s11102-016-0773-7. PMID: 27812776.
  3. 3. Uccella S, Amaglio C, Brouland JP, Bianconi E, Ippolito S, Messerer M, Rouiller N, Tanda ML, Sessa F, La Rosa S. Disease heterogeneity in IgG4-related hypophysitis: report of two histopathologically proven cases and review of the literature. Virchows Arch. 2019 Sep;475(3):373-381. doi: 10.1007/s00428-019-02564-2. Epub 2019 Mar 25. PMID: 30911814.