Clinics and Practice 2011; volume 1:e48

Lymphocitic infundibulo- with (DI). Diagnosis of HYP is based on endocrine dysregulation and Correspondence: Athanasios K. Petridis, neurohypophysitis mimicking abnormal findings on cranial magnetic reso - Department of Neurosurgery, University a nance imaging (MRI). 2 Hospitals Schleswig-Holstein, Campus Kiel, We present the case of a patient, who was Arnold-Heller Str. 3, 24105 Kiel, Germany. Lorenzo Giammattei, 1 admitted to our department with a suspected Tel: +49.431.5978550 - Fax: +49.431.5974883. E-mail: [email protected] Homajoun Maslehaty, 2 diagnosis of a pituitary adenoma, diagnosed as Athanasios K. Petridis, 2 lymphocitic infundibulo-neurohypophysitis Key words: hypophysitis, pituitary adenoma, Hubertus Maximilian Mehdorn 2 after more accurate neuroradiological and endocrinology.

1 endocrinological investigations. Department of Neurosurgery, University Contributions: the first and second authors have of Milan, Fondazione IRCCS Ospedale contributed equally to this study. Maggiore Policlinico, Mangiagalli e Regina Elena, Milan, Italy; 2Department Case Report Received for publication: 24 May 2011. of Neurosurgery, University Hospitals Accepted for publication: 10 June 2011. Schleswig-Holstein, Campus Kiel, A 69-years-old female patient suddenly devel - This work is licensed under a Creative Commons Germany University Medical Center, oped and polydipsia. Laboratory analy - Attribution 3.0 License (by-nc 3.0). Germany sis revealed a central complete DI. Her urinary osmolarity and plasma osmolarity were 70.5 ©Copyright L. Giammattei et al., 2011 mOsm/kg and 317 mOsm/kg respectively with Licensee PAGEPress, Italy Clinics and Practice 2011; 1:e48 oral free water intake. The peak plasma antidi - doi:10.4081/cp.2011.e48 Abstract uretic hormone (ADH) level measured by radioimmunoassay was 1.3 pg/mL when plasma A rare case of infundibulo-neurohypophysi - osmolarity was 317 mOsm/kg. Serum sodium tis mimicking a pituitary adenoma is present - and potassium concentration were 144 mmol/L ed. A 69-years-old female patient developed and 4.1 mmol/L. Urinary sodium and potassium Discussion polyuria and polydipsia. Laboratory analysis levels were 108 mmol/L and revealed central diabetes insipidus. No hor - 37 mmol/L respectively. Cranial MRI showed a aHYP is considered to be an autoimmune monal abnormalities. Cranial-magnetic reso - left-sided adenohypophyseal mass featuring a reaction in the anterior fre - nance imaging (MRI) showed a left sided mass pituitary adenoma (Figure 1A and B). The mass quently associated with female gender, preg - in the adenohypophysis presuming a pituitary appeared to contact both internal carotid arter - nancy or presenting during the postpartum adenoma. The mass had contact to both inter - ies without deviation of the stalk or connection period. 3 However, according to different autop - nal carotids. Admission to our department for to the optic chiasm. She was admitted to our sy series occurrence of aHYP could also been neurosurgical treatment followed. Ophthalmo - department for neurosurgical tumour removal. shown in males. 4 aHYP most commonly pres - logic examination and neurological examina - On physical examination she showed no signs ents with symptoms of sellar mass with or tion yielded normal findings. A second MRI other than dry mouth and coated tongue. without varying degrees of , focussing on the sellar-region showed a left- Ophthalmologic and neurological examination whereas DI is uncommon. 5 nHYP is a distinct sided (T2-MRI.hyperintense), distended ade - yielded normal findings. Her past history includ - entity, first reported by Imura, in which inflam - nohypophysis, without contrast enhancement ed an intracerebral hemorrhage in 1996 treated mation is confined to the hypothalamic-neuro - in T1. The stalk appeared thickened. T1- by evacuation of the hematoma, decompressive hypophysial system frequently presenting with weighted sequences of the neurohypophysis craniectomy followed by reconstructive cranio - DI. 2,6 DI is a clinical syndrome, characterized showed loss of signal intensity. We diagnosed plasty. No evidence for recent head trauma or by polyuria and polydipsia, which can be divid - an infundibulo-neurohypophysitis and abstai - infections. Basal anterior pituitary function ed in central (ADH deficit) and nephrogenic ned from surgical removal. The patient was tests were normal except for low increase of type (ADH-resistant). Central DI is usually discharged under treatment with corticos - Human Growth Hormone (18.10 ng/mL) which caused by head trauma, infections, inflamma - teroids and desmopressin. Hypophysitis is rare was probably stress-related. The clinical signs, tions (e.g. meningitis, hypophysitis) or neo - and shows special clinical characteristics. the results of the laboratory data and the evalua - plasms (e.g. adenoma). Inflammatory process - Despite defined radiological features to differ - tion of MRI were not convincing upon the diag - es of the hypophysis can be easily misdiag - entiate between hypophysitis and adenoma nosis of pituitary adenoma. We performed a sec - nosed because of their clinical and radiological the possibility of misdiagnosis, and unneces - ond MRI focused on the sellar region. MRI features mimicking tumors in the sellar or sary surgical procedures, should always kept in showed a left-sided distended adenohypophysis parasellar region. MRI has improved the diag - mind. with highly intense signal in the T2-weighting, nostic accuracy by differentiating HYP from without contrast enhancement in the T1-weight - pituitary tumours. 4 ing. The stalk appeared thickened. HYP usually presents as symmetrical Predominantly remarkable was the loss of signal enlargement of the pituitary gland while it is Introduction intensity in the T1-weighted sequences of the asymmetrical in patients with adenoma. The neurohypophysis (Figure 1C). Combining our stalk is thickened but non-deviated while devi - Lymphocytic hypophysitis (HYP) is a rare test results we drew the diagnosis of nHYP as ation of the stalk is observed commonly in ade - inflammatory condition classified in adeno- our conclusion and abstained from surgical pro - nomas. Patients with HYP show an intense hypophysitis (aHYP), infundibulo-neuro- cedure. The patient was discharged and was and homogenous enhancement of the mass hypophysitis (nHYP) and panhypophysitis. 1 treated with 50 mg corticosteroid twice a day and after gadolinium contrast and also a strip of aHYP mainly occurs in women, often during desmopressin spray. Six months later her condi - enhanced tissue along the dura mater (dural pregnancy or postpartum period, causing tion was stable, but the symptoms were not tail) while patients with adenoma show a hypopituitarism, while nHYP usually presents declining. slightly delayed and inhomogenous enhance -

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ment. The neuroimaging findings that could emerging clinical entity. Endocr J 2009;56: lead in particular to the diagnosis of nHYP are 1033-41. the absence of abnormalities in anterior pitu - 2. Imura H, Nakao K, Shimatsu A, et al. itary gland, the thickening of the pituitary Lymphocytic infundibuloneurohypophysi - stalk and the enlargement of the neurohypoph - ysis. Furthermore a signal loss of the posterior tis as a cause of central diabetes insipidus. lobe on T1-weighted images is characteristic. 2 N Engl J Med 1993;329:683-9. Apart from these schematic differences it is 3. Yamazaki M, Sato A, Nishio S, et al. important to note that some variants of nHYP Transient polyuria related to central dia - may form a mass not localized in the neurohy - betes insipidus caused by lymphocytic pophysial space but involving the adenohy - infundibulo-neurohypophysitis in a pophysis, thus resembling adenomas and other tumours. 7,8 patient treated for Graves' disease. Intern In these particular cases it is important to Med 2010;49:1885-90. perform a high resolution MRI focussed on the 4. Bellastella A, Bizzarro A, Coronella C, et al. sellar region to notice the thickness of the Lymphocytic hypophysitis: a rare or under - stalk and the signal intensity of the neurohy - estimated disease? Eur J Endocrinol. pophysis, that are the two cardinal signs that 2003;149:363-76. can lead to the correct diagnosis. In patients with the radiological findings 5. Menon SK, Sarathi V, Bandgar TR, et al. mentioned above, presence of DI and normal : a single centre anterior pituitary gland function, the diagnosis experience. Singapore Med J 2009;50: of nHYP should be considered. 1080-4. If clinical and neuroimaging findings are 6. Kamel N, Ilgin SD, Güllü S, et al. typical of this disease, surgical intervention Lymphocytic hypophysitis and infundibu - including biopsy should be avoided since it does not improve the diabetes insipidus and loneurohypophysitis; clinical and patho - can also lead to further endocrine distur - logical evaluations. Endocr J 1999;46:505- bance. 9 Spontaneous remission of this disease 12. can occur but a treatment with immunosup - 7. Nishioka H, Ito H, Sano T, Ito Y. Two cases pressive drugs like glucocorticoids is generally of lymphocytic hypophysitis presenting recommended, even if this therapy seems to be with diabetes insipidus: a variant of lym - effective in only about 30% of all treated patients .4,10,11 The patients should be examined phocytic infundibulo-neurohypophysitis. in follow-up-examinations including MRIs Surg Neurol 1996;46:285-90; discussion closely to register the success of therapy and to 290-1. avoid dysregulation of the . 8. Tashiro T, Sano T, Xu B, et al. Spectrum of different types of hypophysitis: a clinico - pathologic study of hypophysitis in 31 Conclusions cases. Endocr Pathol. 2002;13:183-95. 9. Waki K, Yamada S, Ozawa Y, et al. A case of HYP is a rare constellation with special clin - lymphocytic infundibuloneurohypophysi - ical characteristics. Despite defined radiologi - tis: histophathological studies. Pituitary cal features to differentiate between HYP and 1999;1:285-90. adenoma the possibility of a misdiagnosis, and 10. Kristof RA, Van Roost D, Klingmüller D, et consequently unnecessary surgical proce - dures, is always to be kept in a neurosurgeon´s al. Lymphocitic hypophysitis: non invasive mind. diagnosis and treatment by high dose methylprednisolone pulse therapy? J Neurol Neurosurg Psychiatry 1999;67:398- 402. References 11. Inaba H, Suzuki S, Shigematsu S, et al. Lymphocytic infundibuloneurohypophysi - 1. Shimatsu A, Oki Y, Fujisawa I, Sano T. tis: long-term follow-up of a case cured Figure 1. (A) T1 weighted magnetic reso - Pituitary and stalk lesions (infundibulo- nance imaging: Coronar section of the pitu - hypophysitis) associated with immuno - with glucocorticoid. Med Princ Pract. 2010; itary showing a thick pituitary stalk. The globulin G4-related systemic disease: an 19:79-81. hypophysis seems to be tumorous on the left side. (B) T2 weighted MRI: In the transver - sal section section an adenoma of the left pituitary gland is suspected. (C) On the sagittal section of this T1 MRI the neurohy - pophysis which is normally hyperintense is hypotintense.

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