A case of lymphocytic infundibulo-neurohypophysitis presenting with unique clinical and radiological features

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 163-194-Pituitary Disorders & Case Reports
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-168
Kazuko Ito*1, Toshiro Seki1, Atsushi Yasuda2, Masami Seki3, Masafumi Fukagawa2 and Atsushi Takagi1
1Tokai University School of Medicine, Kanagawa, Japan, 2Tokai Univ Sch Med, Kanagawa, Japan, 3Seirei Numazu Hospital, Shizuoka, Japan
Lymphocytic hypophysitis (LYH) has recently been classified into lymphocytic adenohypophysitis (LAH), lymphocytic infundibulo-neurohypophysitis (LINH), and lymphocytic infundibulo-panhypophysitis (LIPH) according to the affected area. We report a case of LINH in a 68-year-old woman who presented with diabetes insipidus (DI). In this case, the posterior lobe was affected in both endocrinological assessment and magnetic resonance imaging (MRI) findings. In contrast, the anterior pituitary was not affected in endocrinological assessment but was affected in MRI findings. Indeed, the patient did not develop hypopituitarism. We believed that these clinical and radiological features were unique in regard to the classification of LYH. To confirm the classification of LYH and the distinction from pituitary adenoma, a pituitary biopsy was performed. The resected specimen from the posterior part of the pituitary revealed chronic inflammation and lymphocyte and plasma cell infiltration with occasional fibrotic lesions and spindle cells. There was no evidence of neoplasia, granuloma, xanthoma, or plasma cells immunostained with IgG4. Based on the pathological and endocrinological assessment, the patient’s disorder was finally diagnosed as a variant of LINH. Prednisolone and desmopressin acetate (1-deamino-8-D-arginine-vasopressin acetate trihydrate; DDAVP) were started. Over the next 3 months, there was a dramatic reduction in the size of the pituitary gland and stalk compared with MRI findings on admission. Currently, DDAVP is unnecessary, and 5 mg/day of prednisolone is being continued. Recent evidence recommends that surgical intervention for LYH should be avoided because the natural course of LYH is essentially self-limiting. Therefore, the accumulation of the knowledge of many variants of LYH is important for the preoperative differential diagnosis of pituitary masses. Our clinical observation could be useful for avoiding unnecessary surgical intervention.

Nothing to Disclose: KI, TS, AY, MS, MF, AT

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