Endocrine Abstracts

Introduction: Lymphocytic hypophysitis is rare in children, with only <100 cases described in the medical literature, of which only a few are biopsy-proven. Usually results in hypophysis and pituitary enlargement. Arginine vasopressin deficiency and growth retardation are the most significant presenting symptoms in children with hypophysitis, different from teenagers in whom adrenal insufficiency, hypogonadism, headache, or diplopia might be the leading manifestations. Treatment consists of steroids or immunosuppressive therapy.

Case presentation: A 16-year-old previously healthy girl presented with headaches, vomiting, lethargy, binocular strabismus, and 2 months history of polydipsia and polyuria. The endocrine evaluation was based on thyroid and adrenal function assessment, insulin-like growth factor 1 (IGF-1) serum level measurement, gonadotropins, estradiol, and prolactin. The concentration of immunoglobulins, antithyroglobulin antibodies (anti-Tg), thyroid peroxidase antibodies (anti-TPO), tumor markers such as alpha-fetoprotein (αFP), and beta-human chorionic gonadotropin (βhCG), QuantiFERON test, angiotensin-converting enzyme (ACE) were determined. X-ray chest, abdomen computed tomography (CT), and brain magnetic resonance imaging (MRI) were performed. Endocrine investigations showed central hypothyreosis [thyroid-stimulating hormone (TSH) 0.6100 mIU/l (N:0.48–4.17), free thyroxine (fT4) 0.67 ng/dL (N:0.83–1.43)] and arginine vasopressin deficiency. Dehydroepiandrosterone sulfate (DHEA-S) was below the normal range: 30.8 (98.3–413.4) [μg/dL]. Estradiol concentration was 16.49 pg/mL (N:21.9 – 297.2). Normal follicle-stimulating hormone (FSH) level, luteinizing hormone (LH), and prolactin were noticed. The brain MRI identified a T2-hyperintense sellar/suprasellar lesion 10×9×21 mm with a thick rim of enhancement and minimal sella expansion, with pituitary stalk thickening to 4.5 mm. The ophthalmological assessment showed normal visual acuity and fields. Treatment was started with dexamethasone administered intravenously (followed by prednisone per os), desmopressin, and levothyroxine. Headaches, strabismus, and lethargy were completely resolved. After 2 months of steroid treatment, a brain MRI did not reveal the previously described pituitary focal lesion but only a heterogeneous image of the pituitary gland and stalk, indicating an inflammatory process.

Conclusion: Lymphocytic hypophysitis is a rare cause of multihormonal hypopituitarism in children. Differential diagnosis includes neoplasms and other inflammatory diseases. Steroid therapy was effective in our patient. Careful follow-up is necessary to manage endocrine deficiencies, and there is the possibility of recurrence of pituitary inflammatory changes.