Endocrine Journal 1999, 46 (4), 505-512 Lymphocytic Hypophysitis and Infundibuloneurohypophy- sitis; Clinical and Pathological Evaluations NURI KAMEL, SEN DAOcI ILGIN, SEVIMGULLU, VEDIACESUR TONYUKUK AND HALUKDEDA* Department of Endocrinology and Metabolic Diseases, Ankara University Medical School, Ankara, Turkey * Department of Neurosurgery , Ankara University Medical School, Ankara, Turkey Abstract. This report describes the clinical and pathological characteristics of two patients with lymphocytic hypophysitis (LHy) and two with infundibuloneurohypophysitis (INHy). Two of the patients were women and two were men, and their ages were between 27 and 38 years old. This disease was not associated with either pregnancy or the postpartum period in the female patients. Two of the patients presented with diabetes insipidus, one with panhypopituitarism and right abducens paralysis and one with headache and galactorrhea. At presentation three of the patients had mild to moderate hyperprolactinemia and one had low prolactin levels. All four had abnormal magnetic resonance imaging (MRI): focal nodular enlarging of the infundibulum and normal hypophysis in one, expanding sellar masses in two, and diffusely thickened stalk with slightly enlarged pituitary gland in one. Three cases showed no sign of adenohypophysial deficiency with stimulation tests. One patient had associated chronic lym- phocytic thyroiditis. Of the first three patients, one patient underwent transcranial and two underwent transnasal transsphenoidal (TNTS) surgery for mass excisions since they were thought to have pituitary tumors. Endoscopic endonasal transsphenoidal biopsy was performed in the last one with a suspicion of LHy. The pathological and immunohistochemical examinations revealed lymphocytic infiltration. Hyperprolactinemia resolved with surgery in two patients and one developed diabetes insipidus as a complication. We conclude that LHy and infun- dibuloneurohypophysitis should be considered in the differential diagnosis of the mass lesions of the sellar region and also should be kept in the mind for the etiopathogenesis of cases of hyperprolactinemia, galactorrhea and diabetes insipidus. In suspected cases endoscopic endonasal biopsy for the histopathological diagnosis can be a safe ap- proach. Key words: Lymphocytic hypophysitis, Infundibuloneurohypophysitis (Endocrine Journal 46: 505-512, 1999) LYMPHOCYTIC hypophysitis (LHy), which is a disorders and can mimic nonfunctioning pituitary rare inflammatory lesion of the pituitary gland, was adenomas. first described in 1962 by Goudie and Pinkerton [1] Infundibuloneurohypophysitis (INHy), which was and more than 100 cases have been documented since first described by Imura et al. [25], is a different entity then. Although LHy has been reported to be a dis- and involvement of the posterior pituitary and/or ease of females related to pregnancy or the post- pituitary stalk involvement may result in diabetes in- partum period [2-12], it can occur in nonpregnant sipidus (DI) [20, 26, 27]. The etiology of LHy and women and even in men [13-24]. The disease can INHy remains obscure but some evidence exists for cause complete or partial hypopituitarism and visual an autoimmune pathogenesis because of its associa- tion with other autoimmune diseases including thyroiditis, adrenalitis, pernicious anemia, lympho- Received: November 13, 1998 cytic parathyroiditis, atrophic gastritis, retroperi- Accepted: March 12, 1999 Correspondence to: Dr. Sevim GULLU, Ibn-i Sina Hastanesi, toneal fibrosis and the existence of circulating anti- Endokrinoloji ve Metabolizma Hastahklari Bilim Dali, 10. pituitary antibodies [1, 10, 14, 15, 21, 22, 24, 28-31]. Kat, D-Blok, 06100, Samanpazari, Ankara, Turkey In this report we describe four distinct cases with 506 KAMEL et al. either LHy or INHy. All the patients were diag- and 48.0 ng/ml). He had normal serum free T3, free nosed histopathologically. Because three of them T4 and TSH levels and he was negative for thyroid were suspected of having tumors, they all underwent antibodies (Anti-microsomal antibody and antithyro- surgical explorations with initial diagnoses of pituita- globulin antibody). ry neoplasms, but the fourth patient biopsied had a The plasma ACTH, serum cortisol, FSH, LH, free preoperative diagnosis of LHy. The clinical, radio- and total testosterone levels were normal (Table 1). logical and histological features of the patients are Partial hypopituitarism was excluded by means of described. insulin induced hypoglycemia testing with adequate plasma cortisol and growth hormone responses. Case 1 Thyrotropin releasing hormone stimulation test responses were also normal. A 27-year-old man was admitted with a two month His plain lateral sella turcica film was normal. history of polydipsia, polyuria and fatigue. He had T1-weighted magnetic resonance imaging (MRI) had a diagnosis of major depression three years reveled a focal nodular thickening of the infundibu- previously. He had used amitriptyline and lithium lum and a normal hypophysis (Fig. 1). The nodular for two years but stopped the medication over six lesion was enhanced after iv gadolinium administra- months before the presenting complaints. He denied tion. Since the patient was thought to have a tumor head trauma or operation. of this region, right pterional craniotomy was per- His vital signs were normal. There was no res- formed. At operation the pituitary stalk was ob- triction of his visual field and his systemic examina- served to be thicker than normal. An incision was tion was normal. made on the stalk. A gray-white mass was detected His white blood cell count, hematocrit and in the stalk and normal stalk structures were dissected erythrocyte sedimentation rate were normal. Other from this mass and the lesion was removed while acute phase reactants were also found to be negative. protecting the pituitary stalk. No complication oc- Apart from hypernatremia (158 mEq/L), all bio- curred during and after the operation. By light chemical tests were normal. Daily urine volume microscopy, hematoxylin and eosin stained sections was 10.5 L and urine osmolality was 52.7 mOsm/kg, exhibited a diffuse lymphoplasmacytic (mainly lym- Water deprivation and desmopressin tests indicated a phocytic) infiltration (Fig. 2). There was no evidence partial central DI. His serum prolactin levels were of granulomas, giant cells or neoplastic tissue. On found to be high (on two measurements 22.3 ng/ml, immunohistochemical evaluation, the inflammatory Table 1. Preoperative and postoperative hormonal findings of the patients. LYMPHOCYTIC HYPOPHYSITIS 507 and chronic headache. She had regular menses and she was not pregnant or in the postpartum period. On physical examination no abnormality could be detected apart from bilateral galactorrhea. Her visual field evaluation was normal. Laboratory evaluation demonstrated a normal white blood cell count, hematocrit and erythrocyte sedimentation rate. Her biochemical tests were in the normal ranges. She had normal urinary output and normal urine specific gravity. Her serum prolactin level was found to be slightly high (84.0 ng/ml). Both basal (Table 1) and stimulated adenohypophysial and target tissue hor- Fig. 1. Coronal view of MRI of Case 1. Focal nodular mones were normal. thickening of the stalk and a normal hypophysis. Her plain sella film revealed an enlarged sella tur- cica and MRI showed an enlarged pituitary with cells were found to be a polyclonal population of T suprasellar extension (Fig. 3) which was enhanced and B cells with positivity for CD45 (pan leukocyte diffusely after contrast injection. She was operated antigen, 80-85%) and CD20 (B-cell antigen, 15-200%) on by transnasal transsphenoidal (TNTS) surgery. respectively. The diagnosis was lymphocytic infun- After opening the dura a gray-white non-bleeding dibuloneurohypophysiti s . mass was detected. A normal pituitary gland was The patient's prolactin levels returned to normal not detected in the sellar region. It did not seem to and no additional hormonal deficiency occurred be a pituitary adenoma. A frozen section of the (Table 1) after the operation, but his diabetes insipi- mass was reported to be lymphocytic hypophysitis, dus continued. The patient is now receiving replace- and sellar decompression was achieved. ment doses of desmopressin acetate (20 pg/day, The specimens were stained with hematoxylin and bid, via the intranasal route) and he has had no eosin. Light microscopy showed a generalized lym- symptoms along with the treatment. This case was phocytic infiltration. On immunohistochemical reported before [321. evaluation the inflammatory cells were positive for CD45 (100%), CD20 (10%) and negative for CD3 (T- Case 2 cell antigen). After the operation the patient's prolactin levels A 42-year-old woman, sought medical attention six returned to normal and her galactorrhea disappeared months before she was referred to us for galactorrhea and no new hormonal deficiency occurred, but she Fig. 2. The histologic appearance of LHy. Lymphoplasma- Fig. 3. Coronal view of MRI of Case 2. Enlarged pituitary cytic infiltration of the stalk (Hematoxylin-eosin) with suprasellar extension. 508 KAMEL et al. developed DI. After replacement therapy with des- mopressin (20 rig/day, bid, via the intranasal route) her urinary output returned to normal. Case 3 A 35-year-old man with an approximately 15 year history of panhypopituitarism was admitted to our hospital with fatigue, headache, diplopia and loss of libido. He had been receiving