Lymphocytic hypophysitis in the pediatric population

A 7-year-old boy with central diabetes insipidus presenting with thickened pituitary stalk and anti-rabphilin-3A antibody positivity

OBJECTIVES

A highly invasive pathological diagnosis is necessary to differentiate central diabetes insipidus (CDI) with a thickened pituitary stalk. Lymphocytic infundibulo-hypophysitis (LIH) due to autoimmune involvement of the pituitary stalk is a differentiating disease, and anti-rabphilin-3A antibody (Rab3A-Ab) positivity was recently reported.

CASE PRESENTATION

A 7-year-old boy was diagnosed with CDI after having polyuria for two months. He showed growth hormone deficiency with reduced growth rate. Brain magnetic resonance imaging (MRI) revealed a thickened pituitary stalk. The placental alkaline phosphatase level of the cerebrospinal fluid, tumor marker for germ cell tumors, was below the level of sensitivity. No skin or bone findings suggestive of Langerhans cell histiocytosis were detected. Eight months after CDI onset, Rab3A-Ab was positive, and MRI showed shrinking of the thickened pituitary stalk, leading to the diagnosis with LIH.

CONCLUSIONS

Rab3A-Ab is a useful adjunctive diagnostic tool for childhood-onset LIH.

Molecular and Genetic Immune Biomarkers of Primary and Immune-Therapy Induced Hypophysitis: From Laboratories to the Clinical Practice

Hypophysitis is a rare and potentially life-threatening disease, characterized by an elevated risk of complications, such as the occurrence of acute central hypoadrenalism, persistent hypopituitarism, or the extension of the inflammatory process to the neighboring neurological structures. In recent years, a large number of cases has been described. The diagnosis of hypophysitis is complex because it is based on clinical and radiological criteria. Due to this, the integration of molecular and genetic biomarkers can help physicians in the diagnosis of hypophysitis and play a role in predicting disease outcome. In this paper, we review current knowledge about molecular and genetic biomarkers of hypophysitis with the aim of suggesting a possible integration of these biomarkers in clinical practice.

Xanthomatous Hypophysitis Presenting in an Adolescent Girl: A Long-Term Follow-Up of a Rare Case and Review of the Literature

Objective

Primary hypophysitis refers to the isolated inflammation of the pituitary gland not associated with other secondary causes. Among its histopathologic subtypes, xanthomatous is the rarest.

Methods

We describe a 22-year-old woman with xanthomatous hypophysitis (XH), its clinical progression over 8 years as well as the treatment effects of prednisolone and azathioprine. Our patient was first referred for severe short stature and delayed puberty at the age of 14 years.

Results

Investigations revealed multiple pituitary deficiencies. Magnetic resonance imaging showed a pituitary mass whereby a partial resection was performed. A full resection was not feasible due to the location of the mass. The histopathologic analysis of the tissue was consistent with XH. The results of secondary workout for neoplasm, infection, autoimmune, and inflammatory disorders were negative. After surgery, a progressive enlargement of the mass was observed. Two courses of prednisolone were administered with a significant reduction in the mass size. Azathioprine was added due to the unsustained effects of prednisolone when tapered off and the concern of steroid toxicity with continued use. No further increase in the mass size was noted after 6 months on azathioprine.

Conclusion

Glucocorticoid and immunotherapy are treatment options for XH; however, more cases are needed to better understand its pathogenesis and clinical progression.

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.

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.

Hypophysitis (Including IgG4 and Immunotherapy)

Hypophysitis is characterized by inflammation of the pituitary gland that can be primary (PH) or secondary (SH) to other diseases or following drug administration. It may also be classified according to anatomical and histopathological criteria, leading to variable degrees of hypopituitarism and/or compressive symptoms to nearby structures. There has recently been an increase in the number of hypophysitis cases, raising the interest on the spectrum of its pathogenesis, clinical, biochemical/endocrinological, and imaging features. However, the use of conventional biomarkers, including currently utilized pituitary autoantibodies, has relatively limited diagnostic accuracy. Lymphocytic hypophysitis (LH) is the commonest cause of PH, whereas IgG4-related hypophysitis is increasingly being recognized. Histiocytosis and granulomatous diseases are the most frequent causes of SH, although infections and lymphoma have also been reported. The increasing use of immune checkpoint inhibitors in oncology is associated with a high incidence of hypophysitis, providing further understanding of its pathogenesis. Hypophysitis can occur silently and be easily missed, potentially leading to substantial morbidity or mortality due to adrenal insufficiency, requiring a high index of clinical suspicion and timely initiation of appropriate treatment. In most cases of LH or drug-induced hypophysitis, active surveillance along with replacement of established hormonal deficiencies is needed. In the presence of compressive and/or evolving symptoms, treatment with glucocorticoids either alone or in combination with other immunosuppressive agents can be used. Surgical decompression is reserved for nonresponsive cases with threatened vital structures. Timely diagnosis and intervention are important to minimize disease-related morbidity and mortality. We aimed to review current concepts and recent developments in the pathogenesis, diagnosis, and management of hypophysitis.

Clinical presentation and outcome of children with central diabetes insipidus associated with a self-limited or transient pituitary stalk thickening, diagnosed as infundibuloneurohypophysitis

OBJECTIVE

Despite lymphocytic or autoimmune infundibuloneurohypophysitis (INH) is an increasingly recognized aetiology in children with central diabetes insipidus (CDI); clinical data on epidemiology (clinical evolution, predisposing factors, complications), diagnosis and management of this entity are limited and mostly based on published case reports. The aim of this study was to gain a broader insight in the natural history of this disease by analysing the clinical presentation, radiological pituitary stalk changes, associated autoimmunity and hormonal deficiencies in children with CDI and a self-limiting or transient stalk thickening (ST), diagnosed as autoimmune infundibuloneurohypophysitis, during the last 15 years in four Belgian university hospitals.

DESIGN AND PATIENTS

The medical files of nine CDI patients with a ST at initial presentation and no signs of Langerhans cell histiocytosis or germinoma at presentation and/or during follow-up of more than 1.5 years were reviewed.

RESULTS

Age at presentation ranged from 3 to 14 years. Two patients had a positive family history of autoimmunity. Three children presented with associated growth failure, two with nausea and one with long-standing headache. Median maximal diameter of the stalk was 4.6 mm (2.7-10 mm). Four patients had extra-pituitary brain anomalies, such as cysts. One patient had central hypothyroidism, and another had a partial growth hormone deficiency at diagnosis. Within a mean follow-up of 5.4 (1.5-15) years, stalk thickening remained unchanged in two patients, regressed in one and normalized in six children. CDI remained in all, while additional pituitary hormone deficiencies developed in only one patient.

CONCLUSIONS

In this series of children INH with CDI as initial presentation, CDI was permanent and infrequently associated with anterior pituitary hormone deficiencies, despite a frequent association with nonstalk cerebral lesions.

Imaging of the Sella and Parasellar Region in the Pediatric Population

Masses in the sella and parasellar region comprise about 10% of all pediatric brain tumors but type and frequency differs from those in adults. Imaging is critical for diagnosis and characterization of these lesions. By assessing the site of origin, signal and contrast enhancement characteristics, and the presence or absence of characteristic patterns, differential diagnosis can narrow the possibilities. The clinical presentation is often characteristic for lesion type and should be considered. This article summarizes the characteristic imaging features of the most frequent pediatric tumors and tumor-mimicking lesions in children in this region.

Revisitation of autoimmune hypophysitis: knowledge and uncertainties on pathophysiological and clinical aspects

PURPOSE

This publication reviews the accepted knowledges and the findings still discussed on several features of autoimmune hypophysitis, including the most recently described forms, such as IgG4 and cancer immunotherapy- related hypophysitis.

METHODS

The most characteristic findings and the pending controversies were derived from a literature review and previous personal experiences. A single paragraph focused on some atypical examples of the disease presenting under confounding pretences.

RESULTS

Headache, visual field alterations and impaired pituitary secretion are the most frequent clinical findings of the disease. Pituitary biopsy, still considered the gold diagnostic standard, does not always receive consent from the patients. The role of magnetic resonance imaging is limited, as this disease may generate images similar to those of other diseases. The role of antipituitary and antihypothalamus antibodies is still discussed owing to methodological difficulties and also because the findings on the true pituitary antigen(s) are still debated. However, the low sensitivity and specificity of immunofluorescence, one of the more widely employed methods to detect these antibodies, may be improved, considering a predetermined cut-off titre and a particular kind of immunostaining.

CONCLUSION

Autoimmune hypophysitis is a multifaceted disease, which may certainly be diagnosed by pituitary biopsy. However, the possible different clinical, laboratory and imaging features must be considered by the physician to avoid a misdiagnosis when examining a possibly affected patient. Therapeutic choice has to be made taking into account the clinical conditions and the degree of hypothalamic-pituitary involvement, but also considering that spontaneous remissions can occur.

Hypophysitis: Evaluation and Management

Hypophysitis is the acute or chronic inflammation of the pituitary gland. The spectrum of hypophysitis has expanded in recent years with the addition of two histologic subtypes and recognition as a complication of treatment with immune checkpoint inhibitors. Despite the increased number of published cases, the pathogenesis of hypophysitis is poorly understood, and treatment strategies are diverse and controversial. The diagnosis of hypophysitis generally requires histopathologic confirmation. The presentation and clinical course of hypophysitis varies. Hypophysitis can resolve spontaneously, relapse may occur, and some cases can be refractory to treatment.

Pituitary Antibodies in an Adolescent with Secondary Adrenal Insufficiency and Turner Syndrome

BACKGROUND/AIMS

Autoimmune hypophysitis (AH) is a rare inflammatory disease of the pituitary gland causing varying degrees of hypopituitarism and/or sellar compression. Cranial MRI remains the best noninvasive tool to diagnose AH, although a diagnosis of certainty requires pituitary biopsy. The objective of this study was to assess the utility of detecting pituitary antibodies for the diagnosis of AH.

METHODS

A 15-year-old female with Turner syndrome (TS), hypothyroidism, and ovarian failure presented acutely with hypocortisolism. Laboratory studies revealed secondary adrenal insufficiency. MRI showed a hypotrophic pituitary gland and loss of the posterior pituitary bright spot. To establish an autoimmune basis for the adrenal insufficiency, serum was analyzed by double indirect immunofluorescence for the presence of pituitary autoantibodies.

RESULTS

The patient's serum contained autoantibodies that recognized 36% of the adrenocorticotropic hormone-secreting cells, suggesting that these adenohypophyseal cells were targeted by autoimmunity. The serum contained antibodies that identified the majority of the gonadotropin-secreting cells (FSH 77%, LH 65%). No recognition of GH-, prolactin-, and TSH-secreting cells was found. Preabsorption experiments showed that antigenic targets of autoantibodies were not anterior pituitary hormones themselves.

CONCLUSION

Demonstration of circulating pituitary antibodies expands the diagnostic options for AH. In this adolescent with TS, positive and cell-specific pituitary antibodies suggested that AH was the cause of her secondary adrenal insufficiency.

Lymphocytic hypophysitis associated with pediatric multiple sclerosis

BACKGROUND

Lymphocytic hypophysitis (LH) is a rare inflammatory disorder of the pituitary gland and infundibulum most often observed in the setting of autoimmune disease with a variety of clinical and endocrine presentations. The association between lymphocytic hypophysitis and multiple sclerosis has not been reported.

PATIENT AND RESULTS

We describe an adolescent boy with polyfocal neurological signs including optic neuritis as well as hypopituitarism and diabetes insipidus related to lymphocytic hypophysitis. His imaging met 2010 McDonald criteria for multiple sclerosis. This diagnosis was further supported by cerebrospinal fluid analysis and a negative evaluation for an alternate diagnosis. Imaging features of lymphocytic hypophysitis include an absent posterior pituitary bright spot with an enlarged cystic pituitary gland, stalk thickening, and improvement with corticosteroid therapy.

CONCLUSIONS

Lymphocytic hypophysitis and multiple sclerosis share a common autoimmune pathogenesis, perhaps explaining the co-occurrence of the diseases. The presentation of endocrinologic disturbances such as diabetes insipidus with typical features of a multiple sclerosis attack should prompt further investigation of possible comorbid inflammatory disease involving the hypothalamic-pituitary axis.

Use of serum pituitary antibodies to improve the diagnosis of hypophysitis

Lymphocytic hypophysitis is characterized by an extensive infiltration of lymphocytic cells. Pituitary biopsy is the gold diagnostic standard for lymphocytic hypophysitis but the disease occurs with moderate or without pituitary enlargement. The role of antipituitary antibodies (APA) in autoimmune hypophysitis is still discussed due to various methodological difficulties. Indirect immunofluorescence, a widely employed method to detect APA at this time produces highly variable results due to the use of human or animal pituitary substrates. For many years the authors have conducted a re-evaluation of APA by immunofluorescence in patients with other autoimmune diseases and in patients with apparently idiopathic hypopituitarism, using pituitary from young baboons as substrate but considering a predetermined cut-off of the titer and immunofluorescence pattern. This procedure allowed us to find out those with autoimmune pituitary impairment and to foresee the kind of future hypopituitarism in those with pituitary function still normal. Moreover, in APA positive patients, the use of a second step of a double immunofluorescence method allowed identification of the pituitary cells targeted by APA, verifying the correspondence with the kind of hypopituitarism, also when present in subclinical stage. However, to carry out an international workshop comparing the detection of APA by immunofluorescence using different substrates could contribute to verify the best choice to improve the sensitivity and specificity of this method.

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.

Severe Hypoglycemia due to Isolated ACTH Deficiency in Children: A New Case Report and Review of the Literature

Isolated ACTH deficiency causes life-threatening severe hypoglycemia. A 7-year-old girl with hypoglycemia due to this rare disorder is described. Our patient had undetectable plasma ACTH repeatedly and cortisol 0 mcg/dl before and after ACTH 1-24 stimulation. There was no evidence of other pituitary hormone deficiency. Glucocorticoid replacement therapy resulted in resolution of all symptoms and normalization of blood glucose. Previously published data on isolated ACTH deficiency in children is summarized. Review of the literature showed that the prevalence of this condition could be underestimated in the neonatal period and in Prader-Willi syndrome. Isolated ACTH deficiency occurs in older children as well as in neonates.

Pediatric sellar and suprasellar lesions

Masses arising in the sella turcica and the suprasellar region are common in children. The type and frequency of the various lesions encountered in childhood differ from the adult presentation. This article reviews the embryology of the pituitary gland and its normal appearance in childhood as well as the imaging and clinical findings of the common and some of the uncommon lesions arising in the sella turcica, the pituitary stalk, the suprasellar cistern and the lower third ventricle in the pediatric population.

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.

Gamma Knife surgery for lymphocytic hypophysitis

Lymphocytic hypophysitis is a relatively uncommon autoimmune inflammatory disorder affecting the pituitary gland. It most frequently occurs in women of child-bearing age. The authors report on their experience with a patient who presented with diplopia and marked enlargement of the pituitary gland. She underwent transsphenoidal surgery, and histopathological analysis confirmed the diagnosis of lymphocytic hypophysitis. The disease proved refractory to resection, and any attempt at withdrawal of corticosteroid therapy resulted in a return of the patient's symptoms and enlargement of the sellar contents.

The patient underwent Gamma Knife surgery (GKS) to the sella and both cavernous sinuses. After GKS, the patient was able to discontinue steroid therapy without return of her symptoms. Follow-up MR images demonstrated no evidence of recurrence of lymphocytic hypophysitis.

For persistent lymphocytic hypophysitis, GKS is a reasonable treatment option.

Imaging of pediatric pituitary abnormalities

Evaluation of the sella and surrounding structures in pediatric endocrinopathies is best performed with high-resolution magnetic resonance imaging. Adequate assessment relies not only on determining the size and shape of the gland but also on confirming normal signal characteristics and homogeneous parenchymal enhancement. Surrounding structures, including the hypothalamus-infundibulum-stalk and the skull base and midline structures about the cerebral hemispheres, warrant careful attention to identify any associated abnormalities. Tumors, whether they arise in the gland or affect gland function through mass effect, are usually well resolved on today's scanners and imaging provides accurate characterization of these lesions.

Lymphocytic infundibulo-neurohypophysitis: An unusual cause of recurrent optic neuropathy in a child

Lymphocytic infundibulo-neurohypophysitis (LINH), a rare autoimmune disease, is distinct from lymphocytic hypophysitis and is characterized by lymphocytic and plasma cell infiltration of the posterior lobe of the pituitary and the pituitary stalk.(1) We report the case of a young boy who presented with recurrent, steroid-responsive optic nerve dysfunction and diabetes insipidus. T1-weighted magnetic resonance imaging scans of the brain showed an isointense soft tissue mass within the sella turcica and a thickened pituitary stalk. Tissue specimen resected at transsphenoidal surgery revealed chronic inflammation with infiltration of lymphocytes and no granulomatosis or necrosis, establishing the diagnosis of LINH.(2) This is the first report of optic neuropathy in association with LINH in a child.