American Journal of Neuroradiology 26:357-359, February 2005
© 2005 American Society of Neuroradiology
Case Report
BRAIN
Presumed Infundibuloneurohypophysitis: Unusual Presentation in a Postpartum Patient
Harish K. Panickera,
Natasa Janicicb,
Dan Nguyena and
Joseph Verbalisb
a Department of Neuroradiology Georgetown University Hospital, Washington, D.C
b Department of Endocrinology, Georgetown University Hospital, Washington, D.C
Address correspondence to Dan Nguyen, MD, Director of Neuroradiology, Georgetown University Hospital, CCC Building, Room C2201, Washington, D.C. 20007-2113
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Abstract
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Summary: We describe a case of presumed postpartum infundibuloneurohypophysitis,
which is a rare inflammatory process involving the pituitary
stalk and posterior pituitary. Only one case has been previously
reported in a postpartum woman. Serial MR images obtained in
our patient revealed spontaneous regression of inflammation.
The critical position of the inflammation leads to hormonal
deficiencies, mostly involving the posterior pituitary. Treatment
options include hormone replacement; the role of pharmacological
steroids is controversial.
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Introduction
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Infundibuloneurohypophysitis typically presents with diabetes
insipidus. It is an uncommon disorder, likely of autoimmune
origin. To the best of our knowledge, only one case in a postpartum
patient has been reported in the literature (
1). Here we report
another case in a postpartum patient.
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Case Report
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A 22-year-old woman presented for evaluation of polyuria and
polydipsia. Her symptoms started approximately 6 months after
she had uncomplicated vaginal delivery. The patient reported
urine volume >8 liters per day. She was unable to resume
menstrual cycles and had persistent galactorrhea. On review
of systems, she had 10 kg of weight gain over 6 months and reported
headaches but denied blurred vision. Her medical and family
histories were unremarkable, and she was not taking any medications.
Visual fields were intact to confrontation. Laboratory data
were remarkable for serum osmolality of 300 mOsm/kg H
2O and
urine osmolality of 62 mOsm/kg H
2O with serum sodium of 153
mEq/L, confirming the clinical diagnosis of diabetes insipidus.
MR imaging of the brain (1.5T MR system) showed a solid enhancing
mass within the pituitary infundibulum measuring 3
x 5
x 4 mm
located just inferior to the optic chiasm with loss of posterior
pituitary hyperintensity (
Fig 1A–C). Anterior pituitary
function testing—including prolactin, luteinizing hormone
(LH), follicle-stimulating hormone (FSH), thyrotropin (TSH),
free thyroxin 4 (FT4), and corticotropin (ACTH) stimulation
tests—was normal. Visual field testing, serum angiotensin-converting
enzyme (ACE) level, and chest radiography findings were normal.
Lumbar puncture did not reveal any evidence of malignancy by
cytology.
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FIG 1. MR images obtained in a postpartum 20-year-old woman with presumed infundibuloneurohypophysitis.
A, Sagittal precontrast T1-weighted image demonstrates thickening of the superior aspect of infundibulum with loss of posterior pituitary hyperintensity.
B and C, Sagittal (B) and coronal (C) contrast-enhanced T1-weighted images demonstrate enhancement of the thickened superior infundibulum.
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On the basis of clinical presentation, laboratory, and imaging data, a presumptive diagnosis of infundibuloneurohypophysitis was made. Differential diagnosis also included germinoma and granulomatous diseases such as sarcoidosis. These were, however, considered to be unlikely in view of normal serum ACE level, chest radiography findings, and lumbar puncture results. Therapy with desmopressin (DDAVP) nasal spray 10 mg twice a day and parlodel 7.5 mg at bedtime was initiated. The patient had prompt resolution of polyuria and a decrease in galactorrhea shortly after starting the therapy. She continued to have weight gain, however, and had not resumed menses 9 months later, so cyclical estrogen therapy with oral contraceptives was started. During her last follow-up visit, she continued to complain of weight gain. No other hormonal deficiencies were detected. The patient continues to take DDAVP and oral contraceptives. Serial pituitary MR images revealed a gradual decrease in size of the enhancing superior infundibular lesion. Follow-up imaging after 4 years shows total resolution of contrast enhancement (Fig 2).
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FIG 2. Contrast-enhanced sagittal T1-weighted image demonstrates resolution of contrast enhancement and thickening of the superior aspect of infundibulum.
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Discussion
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Lymphocytic hypophysitis is a rare noninfectious, probable autoimmune
inflammatory disorder of the pituitary (
1–
6). Depending
on the location of the lesion, they have been characterized
into lymphocytic adenohypophysitis (LAH) (
3,
5) with or without
involvement of the neurohypophysis and lymphocytic infundibuloneurohypophysitis
(LIN) (
1,
2,
4). LAH rarely presents with diabetes insipidus
(
5), whereas this is usually the presentation in cases of LIN
(
2,
4).
LAH, the more frequent of the two, has been described mostly in the postpartum period, although there are reports of this disease occurring in men and postmenopausal women (3). Hashimoto et al (3) reviewed 124 cases of lymphocytic adenohypophysitis, and nearly 60% of them had onset of disease in relation to pregnancy. Lymphocytic and plasma cell infiltration of the anterior pituitary has been verified histologically in LAH (6). Lymphocytic adenohypophysitis presents with an enlarged enhancing anterior pituitary with isolated or multiple hormonal deficiencies. Generally, in the ascending order, are deficiencies of growth hormone, serum prolactin, FSH/LH, TSH and ACTH are involved (4). A possible hypothesis to explain this phenomenon is the topographical location of pituitary cells and the centrifugal pattern of pituitary blood flow, which lead to progressive spreading of inflammation in that order.
LIN typically presents as central diabetes insipidus (2, 4, 5) as seen in our patient. Imura et al (2) reviewed 17 cases of idiopathic diabetes insipidus; MR imaging findings were consistent with those of LIN. Two of these patients had histologic verification of T-cell infiltration of infundibulum and neurohypophysis. The lesion typically is isolated to the pituitary stalk. The posterior pituitary retains its connections with the hypothalamus, via the hypothalamic hypophyseal tract, and functions as a primary reservoir for vasopressin and oxytocin, unlike the anterior pituitary, which has the capability of synthesizing its own hormones. Anterior pituitary function can be affected in LIN by the critical location of the lesion in the stalk leading to disruption of regulatory hormones or secondary to progression to involve the adenohypophysis. Most of the reported cases of LIN, however, remain isolated to the pituitary stalk without extension to involve the adenohypophysis or anterior pituitary hormonal deficiency (1, 2, 4). The MR imaging finding of an enhancing mass in the stalk is often associated with loss of hyperintensity in the posterior pituitary, although isolated absence of the hyperintense posterior pituitary could be a normal variant (7). Why MR imaging and histologic studies show disease to be restricted to the posterior pituitary remains unknown (8). The differential diagnosis includes sarcoidosis, Wegner granulomatosis, eosinophilic granuloma, metastasis, neoplasm-like germinoma, and, rarely, syphilis. Enlargement of the stalk can have tumor-like appearance, and some patients have undergone pituitary exploration because of suspicion of a pituitary tumor (9).
Our patient did not have a clinical or laboratory manifestation of the above entities and presented in the postpartum period. Our review of literature revealed only one reported case of LIN presenting in postpartum women (1). None of 17 patients in the Imura series (2) presented in the postpartum period. In two of the 17 patients who received glucocorticoid treatment after surgery, the width of the pituitary stalk diminished. The lesions regressed spontaneously in the other 15 patients (2). The clinical and radiological presentation in our patient was classic infundibuloneurohypophysitis, possibly of lymphocytic origin; after discussion with the patient, we chose to follow up the patient with hormone replacement therapy and to forgo performing a biopsy to verify the diagnosis.
Both adenohypophysitis and lymphocytic infundibulohypophysitis have long been considered to be of autoimmune origin but with different antigenic stimuli (2, 10). In LIN, the self-limiting inflammatory process is compatible with the autoimmune hypothesis of idiopathic diabetes insipidus (2). The preponderance of women in published series (2) and the presence of T-cell infiltration in biopsy-proved cases also favor this hypothesis. Presentation in the postpartum period in our patient also supports this hypothesis. Moreover, reports of coexistence of LIN with other autoimmune diseases such as lupus erythematosis also suggest an autoimmune etiology of this disorder (5, 11). Vasopressin cell antibodies (AVP) have been found in patients with idiopathic diabetes insipidus with or without other autoimmune diseases (10). Recently, De Bellis et al (12) showed the presence of AVP antibodies in patients with diabetes insipidus and pituitary stalk thickening consistent with LIN. In the same series, patients with diabetes insipidus but without pituitary stalk thickening did not have AVP antibodies. Therefore, the presence of AVP antibodies appears to be a good marker of autoimmune diabetes insipidus in patients with LIN (12).
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Conclusion
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Our patient was treated with DDAVP only, and steroid treatment
was not initiated. On serial MR images, the mass showed spontaneous
regression, which is consistent with the presumptive diagnosis
of infundibuloneurohypophysitis. The patient remains on desmopressin
consistent with most other cases that show permanent diabetes
insipidus. We believe that, in the proper clinical context,
an invasive biopsy with possible detrimental complications can
be avoided and close follow-up with MR imaging and supportive
hormonal therapy is the most judicious option.
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References
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- Havenbergh TV, Robberecht W, Wilms G, et al. Lymphocytic infundibulohypophysitis presenting in the postpartum period: case report. Surg Neurol 1996;46:280–246[Medline]
- Imura H, Nakao K, Shimastu A, et al. Lymphocytic infundibuloneurohypophysitis as a cause of central diabetes insipidus. N Engl J Med 1993;329:683–689[Abstract/Free Full Text]
- Ahmed SR, Aiello DP, Page R, et al. Necrotizing infundibulo-hypophysitis: a unique syndrome of diabetes insipidus and hypopituitarism. J Clin Endocrinol Metab 1993;76:1499–1504[Abstract]
- Tubirdy N, Saunders D, Thom M, et al. Infundibulohypophysitis in a man presenting with diabetes insipidus and cavernous sinus involvement. J Neurol Neurosurg Psychiatry 2001;71:798–801[Abstract/Free Full Text]
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- Nishioka H, Ito H, Sano T, Ito Y. Two cases of lymphocytic hypophysitis presenting with diabetes insipidus: a variant of lymphocytic infundibulo-neurohypophysitis. Surg Neurol 1996;46:285–290[Medline]
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- Kojima H, Nojima T, Nagamshima K, et al. Diabetes insipidus caused by lymphocytic infundibulo-neurohypophysitis. Arch Pathol Lab Med 189;113:1399–1401
- Tsujii S, Takeuchi J, Koh M, et al. A candidate case for lymphocytic infundibulo-neurohypophisitis mimicking a neurohypophysial tumor. Intern Med 1997;36:293–297[Medline]
- Scherbaum WA, Bottazzo GF, Czernichow P, et al. Role of autoimmunity in central diabetes insipidus. In Czernichow P, Robinson AG, eds. Diabetes insipidus in man. Basel: Karger;1985:232–239
- Hashimoto K, Asaba K, Tamura K, et al. A case of lymphocytic infundibuloneurohypophysitis associated with systemic lupus erythematosus. Endocr J 2002;49:605–610[Medline]
- De Bellis A, Colao A, Bizzarro A, et al. Longitudinal study of vasopressin-cell antibodies and of hypothalamic –pituitary region on magnetic resonance imaging in patients with autoimmune and idiopathic complete central diabetes insipidus. J Clin Endocrinol Metab 2002;87:3825–3829[Abstract/Free Full Text]
Received March 16, 2004;
accepted after revision June 13, 2004.
TOP
Abstract
Introduction