ESPE Abstracts

Background: Hypophysitis is a rare inflammatory condition of the pituitary that can mimic a neoplastic lesion. Histopathology subtypes include lymphocytic, granulomatous, xanthomatous, plasmacytic or a mixed picture. Among these, xanthomatous hypophysitis (XH) is the least common with an unknown aetiology. Unlike lymphocytic hypophysitis, which is believed to be autoimmune in origin, XH is rarely reported to be associated with other autoimmune diseases and response to glucocorticoid is less clear.

Case report: We present a girl with XH who was referred for stunted growth and delayed puberty at the age of 14 years. On examination, she was short at 120cm (>2 SD below her mid-parental height) and pre-pubertal. Neurological and visual fields examination were normal. She had multiple pituitary deficiencies (growth hormone, TSH, gonadotrophins) and four years later developed diabetes insipidus. However, she did not develop adrenal deficiency. This was also similar with other cases of XH whereby adrenal deficiency is reported to be less common.

Her first MRI in January 2013 revealed a homogenous lobulated mass, measuring 0.6x1.3x1.7 (APxWxCC) arising from the pituitary stalk with extension to the sellar, suprasellar regions, and abutting the optic chiasm. Autoimmune, infectious and secondary workout for tumor including germinoma was negative. Repeated MRI did not show a change in mass size until three years later there was an increment measuring1.8x 1.4x1.0 cm (APxWxCC). She then underwent a partial resection for diagnostic and therapeutic purposes. A complete resection was not done due to the location and nature of the tumor. Histopathology was suggestive of XH.

Post-resection MRI over a two-year period showed a continued gradual increment of mass size measuring 2.1x1.2x1.6 cm (APxWxCC). After a multi-disciplinary consultation, a decision was made for a trial of steroids. Oral prednisolone 30mg (1mg/kg) once daily was administered for 2 months and tapered off weekly. Repeated MRI six months after completion of prednisolone 1mg/kg/day showed a smaller mass measuring 1.2x1.0x1.4 cm (APxWxCC). While there was still superior displacement of the optic chiasm, her visual acuity and visual fields remained normal.

Conclusion: We report a girl with XH post-surgical resection with a residual progressive lesion that showed a response to glucocorticoid with no acute side effects. While glucocorticoid could be a treatment option for selected cases of XH, there is insufficient evidence to recommend its routine use as well as the best regimen and timing; in addition, understanding of the pathogenesis, progression and prognosis of the disease remains limited.