ESPE Abstracts

Background: Hypophysitis is an uncommon inflammatory disorder of the pituitary gland and is classified both clinically (Primary vs secondary) and histologically (lymphocytic, granulomatous or xanthomatous). Primary hypophysitis is exceptionally rare in the paediatric population with only a few cases reported, the majority being Lymphocytic Hypophysitis.

Case Report: We present the case of a previously healthy 14-year-old boy who attended the emergency room with a 2-day history of fever, headache and vomiting. Initial clinical and laboratory examination were compatible with a diagnosis of bacterial meningitis and intravenous antimicrobial therapy was commenced. After two days of treatment, fever subsided but he continued to complain of headaches and vomiting. CSF culture at this stage was sterile. MRI was performed to rule out Sinus Vein Thrombosis. On MRI a heterogenously enhancing mass-like lesion, involving the hypothalamus, pituitary gland, and stalk, with a necrotic component was demonstrated. Differential diagnosis included a malignant, infectious, or inflammatory process. Laboratory work up revealed panhypopituitarism with central hypothyroidism, hypocortisolism, and low IGF1 and gonadotrophins. Corticosteroid treatment was initiated and after 48 hours Levothyroxine was added. Within 48 hours of initiation of therapy, clinical signs of Diabetes Insipidus emerged, and the diagnosis was confirmed by laboratory testing. Due to the uncertainty regarding the diagnosis, trans-sphenoidal biopsy was performed. Pathology revealed an epithelioid granulomatous process with stellate morphology and disintegration in the central part of the granulomas, present in the anterior pituitary gland tissue. A presumed diagnosis of Granulomatous Hypophysitis was made. Comprehensive work up to rule out a secondary cause was normal, including viral and bacterial serology (Herpes, Enterovirus, CMV, Parainfluenza, Adenovirus, Syphilis, Brucella, Echinococcus and Toxoplasma), a full autoantibody panel, tumour markers, Lysozymes, and TB culture. A decision was made to treat with a 12-week course of Pulse Steroids. Follow- up MRI scans after completion of treatment showed complete regression of the pituitary-hypothalamic process with an atrophic pituitary and thickened stalk. Subsequent dynamic testing of the pituitary-gonadal and growth hormone axis confirmed gonadotrophin and growth hormone deficiency. Growth hormone treatment was commenced with a good response, and subsequently, recombinant LH for induction of puberty. The patient remains under regular MRI surveillance and endocrinology follow-up. No recurrence of the lesion has been demonstrated radiographically. Pituitary function has not recovered.

Conclusion: We present what is, to our knowledge, the first reported case of Idiopathic Granulomatous Hypophysitis in a pediatric patient, presenting clinically as aseptic meningitis with concurrent panhypopituitarism.