Endocrine Abstracts

Lymphocytic infundibuloneurohypophysitis (LINH) is rarely reported due to lymphocyte infiltration in the neurohypophysis. Causes of central diabetes insipidus include idiopathic diabetes insipidus (DI), primary or secondary tumors or infiltrative diseases (such as Langerhans cell histiocytosis, lymphocytic hypophysitis), neurosurgery and trauma.

Case: A 59-year-old female patient presented with complaints of fatigue for 1 month, dry mouth and drinking a lot of water. In the blood tests of the patient, Serum glucose: 97 mg / dL (70-100), Blood urea nitrogen: 35 mg / dL (6-20), creatinine: 0.7 mg / dL (0.7-1.2), sodium: 152 mmol / L (136-145), potassium (K): 4.8 mmol / L (3.5-5.1), hemoglobin: 14.6 g/dl (12.6-17.4), CRP: 8 mg/l (<5), TSH: 2.2 µIU/mL (0.2-4.2), free T4: 1.2ng/dl (0.9-1.7), cortisol: 11 mg/dl (6-18), FSH: 29 mIU/mL (1.5-13), LH : 16 mIU / mL (1.7-8.6), ACTH: 15 ng/l (7-63), prolactin: 30 µg / L (5-10), Ca: 9 (8.6-10 mg/dl), Parathormone: 54 (N: 15-65 pg/ml), ESR: 26 mm (2-20), HbA1c: 5.7%, ANA and ANCA profile: negative, ACE: 23 U/l (13-63), Plasma osmolality : 313 mOsm/l, urinary osmolality: 124 mOsm/l, urine density : 1003. At the 6th hour of the water restriction test, the patient lost 600 g of weight, the urine output decreased by 50cc, the urine density increased to 1009 and sodium to 167 mmol/l. There was a 15% increase in urine osmolality after desmopressin. In the patient’s pituitary MRI, the infindibulum was thick and the hyperintensity of the neurohypophysis disappeared in T1 sequence. Nothing was found in the examinations performed for malignancy screening and colonoscopy. The patient was diagnosed with partial central DI due to Lymphocytic infundibuloneurohypophysitis. In our case, clinical diagnosis was made without biopsy. Since the patient did not have deficiencies in other pituitary hormones, treatment with only desmopressin 10 µg intranasal spray was continued.

Conclusion: Although Lymphocytic infundibuloneurohypophysitis is rare, it should be kept in mind in the differential diagnosis of patients presenting with central diabetes insipidus.

Keywords: Lymphocytic infundibuloneurohypophysitis, Diabetes insipidus