Endocrine Abstracts

Introduction: Pituitary stalk lesions fall into three categories: congenital and developmental (rathke cleft cyst, ectopic neurohypophysis), inflammatory and infectious (hypophysitis, sarcoidosis, tuberculosis), and neoplastic (Langerhans cell histiocytosis, germinoma, metastatic tumors). Herein, we report a case with infundibular lesion presenting with central diabetes insipidus and hypogonadism.

Case report: A 27-years old woman was admitted to our clinic with the story of amenorrhea and polydipsia lasting for three years. She was on desmopressin for two years. Her physical examination was unremarkable. Hormonal profile was: TSH: 0.79 uIU/ml (0.4–4.67), freeT4: 15.49 pmol/l (11.5–22.7), FSH: 2.03 mIU/ml (1.2–15.4), LH: 1.02 mIU/ml (1.24–7.8), Estradiol: 28.7 pg/ml (30–119), Prolactin: 35.3 ng/ml (2.8–29.2), early morning cortisol: 15.2 μg/dl (4.3–22.4) and IGF1: 152 ng/ml (117–329). Pituitary MRI demonstrated a 7×5 mm infundibular mass with suprasellar extension. Diagnostic work-up for infundibular lesions was performed, including; chest X-ray, computed tomography (CT) of thorax, purified protein derivated (PPD) test and measurement of serum angiotensin converting enzyme (ACE) for ruling out granulomatous diseases. Neck ultrasound, bone scintigraphy, skeletal survey, brain CT and measurement of beta-HCG were performed for ruling out infiudibular neoplastic lesions, Serum anti-thyroid peroxidase, anti-thyroglobulin antibody were measured. All were negative. She exhibited no autoimmune background. Serum IgG4 was normal, as well. In addition to existing desmopression, estrogen-progesteron therapy was introduced and menses recovered in a few months. Due to rapid radiological progression at follow-up, methyl prednisolon 1 mg/kg per day was begun for a possible infundibulohypophysitis. Significant radiological regression was observed at the second month of glucocorticoid therapy.

Conclusions: Pituitary stalk lesions have diverse causes and hypophysitis is one of them. In our case, histopathological diagnosis was not possible due to critical location of the infundibular lesion. After detailed work-up, a diagnosis of possible infundibulohypophysitis was made and ampiric glucocorticoid therapy was introduced and resulted in radiological regression.