Lymphocytic hypophysitis with central diabetes insipidus and consequent panhypopituitarism preceding a multifocal, intracranial germinoma in a prepubertal girl

Typing of inflammatory lesions of the pituitary

Inflammatory pituitary lesions account for 1.8% of all specimens from the German Pituitary Tumor Registry. They occure in 0.5% of the autoptical specimens and in 2.2% of the surgical cases. Women are significantly more often affected than men and are often younger when first diagnosed. In general, primary and secondary inflammation can be distinguished, with secondary types occurring more frequently (75.1%) than idiopathic inflammatory lesions (15.4%). In primary inflammation, the lymphocytic type is more common (88.5%) than the granulomatous type of hypophysitis (11.5%). The most common causes of secondary inflammation are Rathke's cleft cysts (48.6%), followed by tumors (17.4%) such as the craniopharyngioma (9.1%), adenoma (5.5%) or germinoma (2.0%). More causes are tumor-like lesions (7.1%) such as xanthogranuloma (3.5%) or Langerhans histiocytosis (3.5%), abscesses (5.5%), generalized infections (5.1%), spreaded inflammations (4.7%) and previous surgeries (4.0%). In 1.6% of all specimens the reason for the inflammation remains unclear. The described classification of hypophysitis is important for specific treatment planning after surgery.

Central Diabetes Insipidus in Children and Adolescents: Twenty-Six Year Experience from a Single Centre

INTRODUCTION

Paediatric cohorts of central diabetes insipidus (CDI) have shown varying prevalence for different causes of CDI. The objective of this study was to determine the causes of CDI and long-term outcome in children and adolescents from a Tertiary Paediatric Endocrinology unit.

METHODS

The clinic database was searched to identify patients with CDI managed between 1993 and 2019. Relevant clinical information was collected from patient records.

RESULTS

A total of 138 CDI patients, median age 6 years (range <1-18) at presentation, were identified. Principal CDI aetiologies were craniopharyngioma (n = 44), acute central nervous system (CNS) insult (n = 33), germinoma (n = 15), postneurosurgery (indication other than craniopharyngioma and germinoma, n = 20), midline CNS malformation (n = 14), Langerhans cell histiocytosis (n = 5), and familial (n = 2). Idiopathic CDI in this cohort was infrequent (n = 5). Patients with CNS malformations/infections presented with CDI at a younger age compared to patients with CNS tumours (p < 0.0001). Five patients, initially presenting as idiopathic CDI, were subsequently diagnosed with germinoma after a median interval of 3.3 years. All patients with CDI related to craniopharyngioma and nearly all (87%) patients with CDI related to germinoma had concomitant GH, ACTH, and TSH deficiency. The majority of patients who manifested CDI due to acute CNS insult either deceased (30%) or had transient CDI (33.3%).

CONCLUSION

Surgery for craniopharyngioma was the most common underlying aetiology of CDI with ubiquitous occurrence of panhypopituitarism in these patients. Manifestation of CDI in patients with acute CNS insult carries poor prognosis. We affirm that neuroimaging assessment in idiopathic CDI should be continued beyond 3 years from diagnosis as a significant number of patients exhibited progression of infundibular thickening 3 years post-CDI diagnosis.

Pituitary Stalk Germ Cell Tumors: Retrospective Case Series and Literature Review

OBJECTIVE

Intracranial germ cell tumors with isolated pituitary stalk involvement are rare. Early recognition and long-term monitoring deserve further exploration.

METHODS

A retrospective study reviewing eleven intracranial germ cell tumor patients with isolated pituitary stalk involvement was performed.

RESULTS

Seven boys and four girls who presented with a hyperintense pituitary stalk on postcontrast T1-weighted magnetic resonance imaging without a posterior pituitary signal were included. The average maximum width of the pituitary stalk was 5.2 ± 1.6 mm. Polydipsia and polyuria occurred in all patients, followed by growth retardation, fatigue, and amenorrhoea. Eight patients (72%) had concomitant partial anterior pituitary hormone deficiency. Seven patients initially had elevated human chorionic gonadotropin levels. After chemoradiotherapy, ten patients attended follow-up. Central diabetes insipidus remained in all survivors, and four (40%) of them had concomitant partial anterior pituitary hormone deficiency, primarily of growth hormone and insulin-like growth factor-1. The causes of the delayed diagnosis of previous studies were mainly negative tumor markers and the initial pathological diagnosis of autoimmune diseases.

CONCLUSION

Isolated pituitary stalk lesions could be a signal of intracranial germ cell tumors, especially coexisting with diabetes insipidus, hypopituitarism, and a worse response to glucocorticoid therapy. Negative results of tumor markers and pathology could not exclude the diagnosis. Chemoradiotherapy is an effective therapy, leaving mild-t-moderate hypothalamus-pituitary dysfunction. This rare neuroimaging feature may be used as a factor to predict long-term neuroendocrine outcomes.

Lymphocytic infundibuloneurohypophysitis with positive anti-rabphilin-3A antibodies nine years post-onset of central diabetes insipidus

Childhood-onset lymphocytic infundibuloneurohypophysitis (LINH) due to infiltration of autoimmune lymphocyte in the neurohypophysis is rarely reported. Its definitive diagnosis requires a pituitary biopsy, which is an invasive procedure. Recently, anti-rabphilin-3A antibody has been reported as a potential diagnostic marker for LINH in adults; however, only a few cases have been reported in children. Here, we present a case of childhood-onset LINH in a 10-yr-old boy identified as anti-rabphilin-3A antibody positive during chronic phase, 9 yr post-onset of central diabetes insipidus (CDI). T1-weighted magnetic resonance imaging (MRI) revealed pituitary stalk thickening and absence of posterior pituitary bright signal spot, and the hormonal responses of the adenohypophysis to GHRH, TRH, CRH, and LHRH revealed no abnormalities during the first admission. MRI at 5 mo post-onset indicated reduced stalk swelling; however, replacement treatment with intranasal desmopressin was continued to counter unimproved CDI. Additionally, GH replacement therapy was also initiated to counter its deficiency. Pituitary re-enlargement was not observed in the subsequent routine MRI, and no increase was observed in the levels of tumor markers during follow-up, which was considered clinically consistent with LINH. Our case study suggests that anti-rabphilin-3A antibody may be considered as a useful diagnostic marker for LINH in children.

Antibodies Against Hypothalamus and Pituitary Gland in Childhood-Onset Brain Tumors and Pituitary Dysfunction

Purpose: To detect the presence of antipituitary (APA) and antihypothalamus antibodies (AHA) in subjects treated for brain cancers, and to evaluate their potential association with pituitary dysfunction. Methods: We evaluated 63 patients with craniopharyngioma, glioma, and germinoma treated with surgery and/or radiotherapy and/or chemotherapy at a median age of 13 years. Forty-one had multiple pituitary hormone deficiencies (MPHD), six had a single pituitary defect. GH was the most common defect (65.1%), followed by AVP (61.9%), TSH (57.1%), ACTH (49.2%), and gonadotropin (38.1%). APA and AHA were evaluated by simple indirect immunofluorescence method indirect immunofluorescence in patients and in 50 healthy controls. Results: Circulating APA and/or AHA were found in 31 subjects (49.2%) and in none of the healthy controls. In particular, 25 subjects out of 31 were APA (80.6%), 26 were AHA (83.90%), and 20 were both APA and AHA (64.5%). Nine patients APA and/or AHA have craniopharyngioma (29%), seven (22.6%) have glioma, and 15 (48.4%) have germinoma. Patients with craniopharyngioma were positive for at least one antibody in 39.1% compared to 33.3% of patients with glioma and to 78.9% of those with germinoma with an analogous distribution for APA and AHA between the three tumors. The presence of APA or AHA and of both APA and AHA was significantly increased in patients with germinoma. The presence of APA (P = 0.001) and their titers (P = 0.001) was significantly associated with the type of tumor in the following order: germinomas, craniopharyngiomas, and gliomas; an analogous distribution was observed for the presence of AHA (P = 0.002) and their titers (P = 0.012). In addition, we found a significant association between radiotherapy and APA (P = 0.03). Conclusions: Brain tumors especially germinoma are associated with the development of hypothalamic-pituitary antibodies and pituitary defects. The correct interpretation of APA/AHA antibodies is essential to avoid a misdiagnosis of an autoimmune infundibulo-neurohypophysitis or pituitary hypophysitis in patients with germinoma.

Intracranial Germinoma Masquerading as Secondary Granulomatous Hypophysitis: A Case Report and Review of Literature

Germinomas are highly immunogenic tumors eliciting a strong peri-tumoral immune response that can spillover into the surrounding healthy tissues. This phenomenon can also occur in intracranial germinomas, manifesting as secondary hypophysitis. Herein, we report a case of 12-year-old-girl presenting with polyuria and polydispsia. She had central diabetes insipidus (CDI) and panhypopituitarism. Imaging revealed a sellar-suprasellar mass with infundibular stalk thickening. Transphenoidal biopsy revealed epithelioid granulomas with immunostaining negative for germinomatous cells. Other causes of hypophysitis were ruled out. Accordingly, she was diagnosed as primary granulomatous hypophysitis and treated with high-dose corticosteroids. Three years later she again presented with headache, vomiting and diminution of vision. Imaging showed a heterogeneous, solid-cystic peripheral rim-enhancing lesion at the same location with involvement of hypothalamus, ependyma and pineal gland. Cerebrospinal fluid beta-human chorionic gonadotropin was markedly elevated, confirming the diagnosis of an intracranial germ cell tumor. She was started on chemotherapy; however, she succumbed to febrile neutropenia. We performed a literature search and found 18 anecdotal cases of secondary hypophysitis associated with intracranial germinomas. There was a slight male preponderance (male:female 5:4). Two-thirds of the cases were below 18 years of age. Polyuria was the most common presenting manifestation (83%). CDI and panhypopituitarism were seen in 89 and 78% cases, respectively. Imaging evidence of pituitary stalk thickening was seen in 12 cases (67%), while pituitary enlargement and/or sellar mass were reported in 11 cases (61%). Pineal involvement was extremely rare, being reported in only 1 case, implying the predilection of suprasellar (rather than pineal) germinomas in causing secondary hypophysitis. Histologically, 82% had lymphocytic hypophysitis, while 18% had granulomatous hypophysitis. Initially, the diagnosis of germinoma was missed in 60% of the cases who were wrongly treated with corticosteroids. To conclude, physicians should make it a dictum that all children and adolescents presenting with CDI and pituitary stalk thickening should be rigorously screened for an underlying intracranial germinoma before labeling them as primary hypophysitis.

Surgical biopsies in patients with central diabetes insipidus and thickened pituitary stalks

Thickened pituitary stalks (TPSs) on magnetic resonance imaging (MRI) result from diverse pathologies; therefore, it is essential to make specific diagnoses for clinical decision-making. The diagnoses and indications for surgical biopsies in patients with central diabetes insipidus (CDI) and TPSs are thoroughly discussed in this paper. Thirty-seven patients with CDI and TPSs were retrospectively reviewed. The mean age at the diagnosis of CDI was 29.0 ± 15.9 years (range 8.0-63.3), and the median duration of follow-up was 5.5 ± 2.8 years (range 0.7-13.0). Anterior pituitary hormone deficiencies were documented in 26 (70.3 %) patients. All patients had a TPS on MRI at the diagnosis of CDI, and 21 (56.8 %) patients exhibited radiological changes during the follow-up. Of these 21 patients, 11 exhibited increases in the thickness of the stalk, and two patients exhibited reversals of the TPSs. Involvements of the hypothalamus, pituitary gland, basal ganglia or supersellar, and pineal gland were found in four, three, one, and 1 patient, respectively. Ultimately, clear diagnoses were established in 17 patients who underwent biopsies, nine of whom had germinomas, six of whom had Langerhans cell histiocytosis, one of whom had a granular cell tumor, and one of whom had Erdheim-Chester disease. Patients with CDI and TPSs should submit to periodic clinic follow-ups with serial MRI assessments to establish anterior pituitary deficiencies and to detect radiological progressions that are appropriate for surgical biopsies. Endoscopic-assisted microsurgery via the supraorbital keyhole approach is a good choice for the biopsy of pituitary stalk lesions.

[Importance of long-term follow-up of diabetes insipidus; from lymphocytic hypophysitis to germinoma]

A case is presented of a 10-year old boy who had a hypothalamic-pituitary axis disorder. He initially presented with diabetes insipidus that progressed to panhypopituitarism. A hidden hypothalamic lesion should be suspected in all these cases, and should be followed up. New lesions were found in the pituitary stem three years later. Although tumor markers were negative, there was an increase in size, and a biopsy was performed. The histopathology reported a Lymphocytic Hypophysitis. There were increases in the tumor markers during the follow-up, thus a second biopsy was performed, with the diagnosis of Germinoma. Lymphocytic Hypophysitis is an uncommon diagnosis in children. Few cases have been reported, and in some cases, they were later diagnosed with Germinoma. We believe this case highlights the importance of the follow-up of children with Central Diabetes Insipidus with a normal MRI, as well as not taking the diagnosis of Lymphocytic Hypophysitis/lymphocytic Infundibular neurohypophysitis as definitive, as it is a rare diagnosis at this age, and could mask a Germinoma, as recorded in some cases.

Predictors of neoplastic disease in children with isolated pituitary stalk thickening

BACKGROUND

The significance of pituitary stalk thickening (PST) on magnetic resonance imaging (MRI) is often unclear. We evaluated presenting symptoms, MRI findings, clinical course, and outcome predictors of patients with PST.

PROCEDURE

We used a computerized search of the medical record from 1995 to 2008 to identify patients with PST without pituitary mass on MRI. Baseline and follow-up MRIs were reviewed in a blinded fashion. Relevant clinical data were abstracted.

RESULTS

69 patients with reported PST and adequate imaging for review were identified; 42 met study criteria. Median age at first abnormal MRI was 13.6 years (range: 0.8-19.7); 43% were male. Median follow-up was 3.4 years (range 0-12.8). Patients with diabetes insipidus (DI) were significantly more likely to have a neoplastic process than those without (P = 0.0008). Of 16 patients with DI, 8 (50%) had a neoplastic process, including germ cell tumor (n = 4), Langerhans cell histiocytosis (n = 3), and lymphoma (n = 1). Among patients with DI, 7 (44%) also developed anterior pituitary hormone dysfunction (APD), either at presentation or on pre-biopsy follow-up, including 6/8 patients with stalk neoplasm and only 1/8 patients with non-neoplastic PST (P = 0.04). Twenty-six patients presented without DI; none was found to have neoplasm of the stalk except one patient with craniopharyngioma. Progression of PST on follow-up imaging was significantly associated with a subsequent neoplastic diagnosis (P = 0.04).

CONCLUSION

Patients with PST without DI are unlikely to have a neoplastic process. Among patients with DI, APD or progressive stalk increase over time are predictive of neoplasia.

Latency of intracranial germ cell tumors and diagnosis delay

BACKGROUND

Intracranial germ cell tumors (GCTs) frequently take an insidious clinical course before diagnosis. To date, clinical latency has been discussed in the context of germinoma in the suprasellar area and basal ganglia.

OBJECTIVE

In this study, we classified the clinical latency of intracranial GCTs into three categories and described their characteristics in order to understand the full spectrum of the phenomenon.

METHODS

In a cohort of 181 patients with intracranial GCTs, 17 patients had a delayed diagnosis of more than 3 months (90 days) from the initial brain magnetic resonance imaging to the definitive GCT diagnosis. Clinical records and radiological data of the patients were reviewed.

RESULTS

The patients with a delayed diagnosis were categorized into three groups according to their tumor location: suprasellar (nine patients), basal ganglia (six patients), and pineal (two patients). Initial symptomatology corresponded with the tumor location: central diabetes insipidus for the suprasellar group, hemiparesis for the basal ganglia group, and precocious puberty for the pineal group. The overall survival of patients with germinoma and delayed diagnosis was significantly shorter than that of patients who were diagnosed within 3 months (P = 0.002).

CONCLUSIONS

Clinical latency and delayed diagnosis are not restricted to germinomas in the suprasellar area and basal ganglia; they are canonical features of intracranial GCTs including pineal non-germinomatous GCTs. Early detection and proactive diagnosis of these tumors are required because diagnosis delay may negatively influence patient survival.

Pituitary and systemic autoimmunity in a case of intrasellar germinoma

Germinomas arising in the sella turcica are difficult to differentiate from autoimmune hypophysitis because of similar clinical and pathological features. This differentiation, nevertheless, is critical for patient care due to different treatments of the two diseases. We report the case of an 11-year-old girl who presented with diabetes insipidus and growth retardation, and was found to have an intra- and supra-sellar mass. Initial examination of the pituitary biopsy showed diffuse lymphocytic infiltration of the adenohypophysis and absent placental alkaline phosphatase expression, leading to a diagnosis of hypophysitis and glucocorticoid treatment. Because of the lack of clinical and radiological response, the pituitary specimen was re-examined, revealing this time the presence of scattered c-kit and Oct4 positive germinoma cells. The revised diagnosis prompted the initiation of radiotherapy, which induced disappearance of the pituitary mass. Immunological studies showed that the patient's serum recognized antigens expressed by the patient's own germinoma cells, as well as pituitary antigens like growth hormone and systemic antigens like the Sjögren syndrome antigen B and alpha-enolase. The study first reports the presence of pituitary and systemic antibodies in a patient with intrasellar germinoma, and reminds us that diffuse lymphocytic infiltration of the pituitary gland and pituitary antibodies does not always indicate a diagnosis of autoimmune hypophysitis.

Lymphocytic hypophysitis in children: a novel presentation and literature review

Lymphocytic hypophysitis, an autoimmune mediated chronic inflammation of the pituitary gland, is uncommon in children.(1) The usual presentation is with symptoms secondary to pressure from the enlargement of the gland itself and or impairment of pituitary hormones of varying degrees, in conjunction with a sellar mass.( 2,3) In 80% of cases, partial or panhypopituitarism is present with approximately 75% of cases having multiple hormonal deficiencies.(2) We report the case of a prepubertal female who presented with cyclical vomiting, as her initial symptom of lymphocytic hypophysitis which resolved promptly after pituitary biopsy. This case suggests that cyclical vomiting can be a symptom associated with lymphocytic hypophysitis. Therefore, it should be considered in the differential diagnosis of any child presenting with cyclical vomiting.

Autoimmune hypophysitis: expanding the differential diagnosis to CTLA-4 blockade

Autoimmune hypophysitis is an increasingly recognized disorder that enters in the differential diagnosis of nonfunctioning pituitary masses. The differential diagnosis of these conditions is challenging because of similar clinical presentations and radiological signs. This review describes the essential features of hypophysitis and the other nonfunctioning pituitary masses. It also emphasizes a recently described feature of hypophysitis: its appearance with unexpectedly high frequency in patients receiving treatments that abrogate the function of cytotoxic T lymphocyte antigen 4.

Lymphocytic infundibulo-neurohypophysitis and infundibulo-panhypophysitis regarded as lymphocytic hypophysitis variant

Lymphocytic infundibulo-neurohypophysitis (LINH) was first reported by Saito et al. and Imura et al. as a cause of idiopathic central diabetes insipidus. Magnetic resonance (MR) imaging with a contrast medium demonstrates thickening of the pituitary stalk, enlargement of the neurohypophysis, or both with homogeneous enhancement. Histological examination reveals a posterior pituitary that is heavily infiltrated by lymphocytes with occasional plasma cells and other inflammatory cells. In early reports of the disorder, the lesion seemed to be limited to the neurohypophysis, but the present review showed cases with a combination of hypopituitarism and diabetes insipidus. Some of them showed partial hypopituitarism. The so-called lymphocytic infundibulo-panhypophysitis (LIPH) is now regarded as a lymphocytic hypophysitis variant. LINH and LIPH are essentially self-limited. In typical cases, conservative care with steroids and hormone replacement is recommended. Surgical intervention should be avoided because the natural course of the disorder may be self-limited. Pathophysiology of the disorder is still unknown. The unique clinical manifestations of the disorder are discussed and reviewed here.

Lymphocytic hypophysitis occurring simultaneously with a functioning pituitary adenoma

Lymphocytic Hypophysitis (LH) is a rare and previously under-recognised disorder, most commonly affecting young females in the post-partum period. It presents clinically with symptoms and signs related to either a pituitary mass or hypopituitarism, frequently mimicking a pituitary adenoma; the diagnosis of LH can only be made histologically with the presence of a dense lymphocytic infiltration usually confined to the anterior pituitary. We present two case histories of patients who presented with symptoms suggestive of a functioning pituitary adenoma who also had concomitant LH confirmed histologically. The first case was a 39 year old lady, with a history of primary hypothyroidism, who presented with weight gain and hirsutism and clinical and biochemical features of Cushing's syndrome. The second case was a 61 year old male, also with a history of primary hypothyroidism, who presented with visual field loss and biochemically with hyperprolactinaemia. In both patients, magnetic resonance (MR) imaging of the pituitary demonstrated an enlarged partially cystic pituitary mass with slight suprasellar extension. Both patients were treated surgically with transphenoidal drainage and excision and histological examination of the surgical specimens demonstrated a mixture of pathologies with fragments of adenohypophyseal tissue (staining positive for ACTH and prolactin respectively) with a dense chronic inflammatory cell infiltrate suggestive of LH in nearby normal anterior pituitary. In both cases a joint diagnosis of a functioning pituitary adenoma with LH was made. There have been only several reported cases of this combination of pathologies but LH even in isolation is becoming increasingly recognised.

Lymphocytic hypophysitis in the pediatric population

BACKGROUND

Lymphocytic hypophysitis (LYH) is a rare inflammatory disease of the pituitary gland that usually affects women in their ante- or immediate postpartum period; males are affected less frequently than females. An autoimmune pathogenesis is suggested. Symptoms comprise anterior and/or posterior pituitary insufficiency of varying degrees. So far, specific characteristics of this rare disease in childhood are not well described.

CASE HISTORY

We report the case of a 12-year-and-11-month-old boy with histologically confirmed LYH clinically presenting with diabetes insipidus. A high-dose steroid therapy was administered, in which the therapeutic effect was uncertain. His 6-year follow-up is presented.

DISCUSSION

The literature is reviewed for children presenting with LYH; their characteristics, pituitary involvement, and clinical follow-up are listed and discussed.

CONCLUSION

Even though magnetic resonance imaging can be highly suspicious for LYH, only surgical exploration can confirm the diagnosis. The efficacy of medical treatment is still controversial; a close follow-up is necessary to control and correct the endocrinological function, if required.

Central Diabetes Insipidus: A Rare Perioperative Cause of Severe Hypernatraemia

In this case report we describe the management of severe hypernatraemia following inadvertent water restriction. A 21-year-old woman with no reported medical history presented on transfer from an outside hospital with a complex volar upper extremity injury. Management both operatively and postoperatively involved a prolonged period of fasting which limited her access to drinking water. Collateral history revealed that she had previously drunk copious amounts of water during the course of any given day and this had served to alleviate the dramatic symptoms of hypernatraemia that were rapidly manifest when her normal intake was curtailed. We outline the fluid management, administration of desmopressin and her subsequent recovery. A literature review of the management of central diabetes insipidus is also covered.

The diagnosis of children with central diabetes insipidus

Central diabetes insipidus is the end result of a number of different diseases that affect the hypothalamic-neurohypophyseal system. In many patients, especially children and young adults, it is caused by the destruction or degeneration of neurons that originate in the supraoptic and paraventricular nuclei of the hypothalamus. The known causes of these lesions include germinoma or craniopharyngioma; Langerhans cell histiocytosis; local inflammatory, autoimmune or vascular diseases; trauma resulting from surgery or an accident; sarcoidosis; metastases; and midline cerebral and cranial malformations. In rare cases, genetic defects in AVP synthesis that are inherited as autosomal dominant, autosomal recessive or X-linked recessive traits are the underlying cause. Accurate diagnostic differentiation is essential for both safe and effective disease management. Proper etiological diagnosis can be achieved via a series of steps that start with clinical observations and then progress, as needed, to more sophisticated methods. Indeed, magnetic resonance imaging (MRI) represents the examination method of choice for evaluating hypothalamic-pituitary-related endocrine diseases due to its ability to provide strongly-contrasted high-resolution multi-planar and spatial images. Specifically, MRI allows a detailed and precise anatomical study of the pituitary gland by differentiating between the anterior and posterior pituitary lobes. MRI identification of pituitary hyperintensity in the posterior part of the sella, now considered to be a clear marker of neurohypophyseal functional integrity, together with careful analysis of pituitary stalk shape and size, have provided the most striking recent findings contributing to the diagnosis and understanding of some forms of 'idiopathic' central diabetes insipidus.

Concurrent lymphocytic hypophysitis and pituitary adenoma. Case report and review of the literature

Lymphocytic hypophysitis (LyH) is an uncommon intrasellar lesion characterized by lymphocytic infiltration of the adenohypophysis. Evidence suggests that the cause is autoimmune, and the symptoms are usually related to either a mass effect or endocrine dysfunction. Lymphocytic hypophysitis has been described rarely in the setting of other simultaneous pathological processes that involve the pituitary and sella turcica, and is postulated to arise from an intrinsic inflammatory response. The authors report the case of a 43-year-old woman who presented with a 2-month history of galactorrhea and pseudohyperprolactinemia secondary to a 10-mm lesion within an enlarged pituitary gland. She was nulliparous and had no contributory medical history. Serial neuroimaging performed over a 2-year period demonstrated lesion growth, and visual deficits had developed; together these warranted surgical intervention. A transsphenoidal resection was performed. Microscopic and immunohistopathological examinations revealed a nonsecreting pituitary adenoma with concurrent lymphocytic adenohypophysitis. This is the first documented case of LyH in the setting of a null-cell pituitary adenoma. The authors review the related literature and outline potential mechanisms for the concurrent development of LyH and a pituitary adenoma.

Lymphocytic hypophysitis with central diabetes insipidus and subsequent hypopituitarism masking a suprasellar germinoma in a 13-year-old girl

CASE REPORT

We report a case of central diabetes insipidus, hypothyroidism, and subsequent hypopituitarism due to lymphocytic hypophysitis masking a germinoma in a 13-year-old pubertal girl. Magnetic resonance revealed an enlarged pituitary gland and a mass lesion in the pituitary stalk and inferior hypothalamus. Open cranial surgery of the anterior pituitary showed active hypophysitis with lymphocytic infiltrates but without necrosis. Despite prednisolone therapy, 1 year later an enlarged, irregular cystic mass lesion had developed; in the pituitary stalk and inferior hypothalamus, a endoscopic biopsy revealed germinoma.

CONCLUSION

Lymphocytic hypophysitis in children may be the first sign of a host reaction to an occult germinoma. The diagnosis of central diabetes insipidus with a thickened pituitary stalk requires long-term follow-up to establish the underlying cause.

Central diabetes insipidus: Is it Langerhans cell histiocytosis of the pituitary stalk? A diagnostic pitfall

Central diabetes insipidus (CDI) is a rare disorder that may be caused by a variety of diseases. In pediatric and adolescent patients the most common causes for CDI are Langerhans cell histiocytosis (LCH) and germinoma. To avoid a potentially hazardous biopsy of the hypothalamic pituitary region it is recommended to evaluate patients with CDI carefully to identify potential extracranial lesions. Since LCH is the most common systemic disease that may cause CDI, special focus is paid to the identification of LCH lesions. We report on a 9(1/2) year old girl who presented with central diabetes insipidus and a thickening of the pituitary stalk on magnetic resonance imaging. Diagnostic workup revealed a history of recurrent ear infections and a compressed 6th thoracic vertebral body on radiographs. Based on these findings LCH was anticipated. Upon growth of the pituitary stalk lesion the patient was treated with LCH standard chemotherapy. After an initial shrinkage of the lesion, a further growth of the pituitary stalk lesion was observed and the tumor was resected. Histopathology revealed germinoma. This case underscores the importance of a istopathologically proven diagnosis in patients with HPR tumors before the initiation of a specific therapy, even if the clinical findings are highly suggestive.

MRI of the hypothalamic-pituitary axis in children

In childhood, the MR characteristics of the normal pituitary gland are well established. During the first 2 months of life the adenohypophysis demonstrates high signal. Pituitary gland height (PGH) decreases during the 1st year of life and then increases, reaching a plateau after puberty. The magnetization transfer ratio (MTR) increases in both sexes up to the age of 20 years. On dynamic contrast-enhanced studies, the posterior pituitary lobe enhances simultaneously with the straight sinus, and the adenohypophysis later, but within 30 s. In genetically determined dysfunctional states, the adenohypophysis may be normal, hypoplastic, or enlarged. Pituitary enlargement, observed in Prop 1 gene mutations, is characterized by a mass interposed between the anterior and posterior lobes. An ectopic posterior lobe (EPP), associated with a hypoplastic or absent pituitary stalk, may be observed in patients with hypopituitarism. Tumors of the hypothalamic-pituitary (HP) axis may be the origin of adenohypophyseal deficiencies. A small hypo-intense adenohypophysis is found in iron overload states and is often associated with hypogonadotrophic hypogonadism. Absence of the posterior lobe bright signal, with or without a thick pituitary stalk or a mass at any site from the median eminence to the posterior pituitary lobe, may be found in diabetes insipidus. Hydrocephalus, suprasellar arachnoid cysts, hypothalamic hamartomas and craniopharyngiomas may result in central precocious puberty (CPP). Increased PGH in girls with idiopathic CPP is useful for its differential diagnosis from premature thelarche (PT). Pituitary adenomas, observed mainly in adolescents, present the same MR characteristics as those in adults.

Autoimmune hypophysitis

Autoimmune (lymphocytic) hypophysitis is a rare disease that should be considered in the differential diagnosis of any nonsecreting pituitary mass, especially when occurring during pregnancy or postpartum. We have analyzed 370 articles published from January 1962 to October 2004 and identified a total of 379 patients with primary lymphocytic hypophysitis. The present review synthesizes the clinical and research data reported in this body of scientific literature.

Intracranial Rosai-Dorfman disease treated with microsurgical resection and stereotactic radiosurgery. Case report

Sinus histiocytosis or Rosai-Dorfman disease (RDD) is a rare idiopathic histioproliferative disorder typically characterized by painless cervical lymphadenopathy, fever, and weight loss. Extranodal, intracranial disease is uncommon. In this report the authors describe the first case of intracranial RDD treated with stereotactic radiosurgery after resection. This 52-year-old man with known RDD presented with a 7-day course of fever, headache, diplopia, left facial paresthesias, and difficulty swallowing. No cranial nerve deficits were evident on examination, but right submandibular and inguinal node enlargements were noted. On neuroimaging, the patient was found to have a homogeneously contrast-enhancing petroclival lesion with extension into the left cavernous sinus. The patient underwent a combined left petrosal craniotomy and partial labyrinthectomy with duraplasty for biopsy sampling and partial microsurgical resection of the lesion. Microscopic examination of the biopsy specimen revealed the presence of a mixed cellular population with predominant mature histiocytes consistent with RDD. The residual tumor was treated with stereotactic radiosurgery 2 months after resection. On follow-up imaging the lesion had regressed significantly, with only slight dural enhancement remaining. Microsurgical resection for histological diagnosis, followed by stereotactic radiosurgery for residual tumor represents one treatment alternative in the management of intracranial RDD in which a complete resection carries the potential for excess morbidity.

Primary central nervous system lymphoma in childhood presenting as progressive panhypopituitarism

We report a 15-year-old boy who had isolated central diabetes insipidus initially diagnosed at age 11 years. A brain magnetic resonance imaging (MRI) was normal at the time. At age 12 years, growth hormone (GH) testing was performed because of a decline in linear growth rate and demonstrated GH deficiency. After a repeat normal brain MRI, GH therapy was begun. Three years later, hormonal testing revealed prepubertal gonadotropins and low testosterone levels, free thyroxine index, and morning cortisol levels. Repeat brain MRI demonstrated a 9-mm enhancing lesion in the region of the pituitary stalk. The pathologic diagnosis was that of a high-grade malignant B-cell lymphoma, suggestive of Burkitt Lymphoma. Growth hormone therapy has not been associated with an increased incidence of lymphoma. This report underscores the need for vigilance in follow-up brain imaging and hormonal evaluation in children with diabetes insipidus, especially those with evolving anterior hormone deficiencies.

Lymphocytic hypophysitis masking a suprasellar germinoma in a 12-year-old girl--a case report

Case history, light and electron microscopic findings of a case of a lymphocytic hypophysitis in coincidence with a suprasellar germinoma in a 12-year-old girl are reported. The girl presented with a long time case history of diabetes insipidus and subsequent panhypopituitarism. Two years after the diagnosis of diabetes insipidus magnetic resonance imaging (MRI) showed a tumorous enlargement of the sellar content and pituitary stalk. A transnasal exploration was initially performed and revealed a lymphocytic hypophysitis. Light microscopy showed a dense infiltration of mature lymphocytes and plasma cells in the interstitium of the anterior pituitary gland. The stalk area could not be exposed to exclude a germinoma. One year later the lesion relapsed despite dexamethason therapy and a second operation by another neurosurgeon had to be performed. Light microscopy showed lymphocytic infiltrates, fibrosis and necrosis. The diagnosis was a lymphocytic hypophysitis again. Though transcranially exposed only pituitary tissue was removed. No infundibular mass became visible at surgery as shown by MRI. The girl developed five months later multiple cerebral lesions, which revealed to be a germinoma. Lymphocytic hypophysitis in children is very rare and a coincidence with a germinoma has not been described from histopathological aspect until now. The origin of the pituitary infiltration is discussed.