Xanthogranulomatous hypophysitis: a rare and often mistaken pituitary lesion

[摘要] Xanthogranulomatous hypophysitis (XGH) is a very rare form of pituitary hypophysitis that may present both clinicallyand radiologically as a neoplastic lesion. It may either be primary with an autoimmune aetiology and can occur in isolation oras a part of autoimmune systemic disease or secondary as a reactive degenerative response to an epithelial lesion(e.g. craniopharyngioma (CP), Rathke’s cleft cyst, germinoma and pituitary adenomas) or as a part of a multiorgan systemicinvolvement such as tuberculosis, sarcoidosis or granulomatosis. It may also present with a variation of symptoms inchildren and adults. Our case series compares the paediatric and adult presentations of XGH and the differential diagnosesconsidered in one child and two adult patients, highlighting the wide spectrum of this condition. Endocrine investigationssuggested panhypopituitarism in all three patients and imaging revealed a suprasellar mass compressing the optic chiasmsuggestive of CP or Rathke’s cleft cyst in one patient and non-functioning pituitary macroadenoma in two patients. Magneticresonance imaging (MRI) demonstrated mixed signal intensities on T1- and T2-weighted sequences. Following endoscopictranssphenoidal surgery, histological analysis revealed necrotic material with a xanthogranulomatous reaction confirmingXGH in two patients and a necrobiotic granulomatous chronic inflammatory infiltrate with neutrophils in one patient,which is not typical of current descriptions of this disorder. This case series describes the wide spectrum of XGH disease thatis yet to be defined. Mixed signal intensities on T1- and T2-weighted MRI sequences may indicate XGH and diagnosis isconfirmed by histology. Histological variation may indicate an underlying systemic process.

[学科分类] 血液学

[关键词] Paediatric;Adolescent/young adult;Adult;Female;Male;White;United Kingdom;Pituitary;Pituitary;Hypophysitis;Panhypopituitarism;Hypopituitarism;Pituitary adenoma;Diabetes insipidus – neurogenic/central;Pituitary apoplexy;Prostate cancer;Osteoporosis;Rheumatoid arthritis;Xanthogranulomatous hypophysitis;Headache;Visual disturbance;Amenorrhoea;Puberty (delayed/absent);Anorexia;Abdominal pain;Nausea;Bloating;Hyperprolactimaemia;MRI;Histopathology;Thyroid function;T4;TSH;Pituitary function;Bone age;Transsphenoidal surgery;Hydrocortisone;Glucocorticoids;Desmopressin;Thyroxine (T4);Testosterone;Growth hormone;Paediatrics;Radiology/Rheumatology;Surgery;Insight into disease pathogenesis or mechanism of therapy;January;2015