Xanthomatous Hypophysitis Is Associated with Ruptured Rathke's Cleft Cyst

Inflammation of adenohypophysis is commonly associated with headache in surgically managed Rathke's cleft cysts

PURPOSE

Rathke's cleft cysts (RCC) are present in up to 20% of autopsy studies but only a minority necessitate surgical treatment. Inflammation of RCC is thought to be significant in three processes: the development of classical symptoms, a predisposition to rupture or apoplexy, and increasing the rate of RCC recurrence. We aim to characterize clinical presentation, histological and radiological findings in patients with surgically managed RCC.

METHODS

We conducted a retrospective case series of 31 RCC, which had undergone surgical management between April 2016 and April 2024. Histopathology and radiology were independently reviewed by neuropathologist and neuroradiologist, and case notes were reviewed for clinical and biochemical data.

RESULTS

Median age was 43 years (IQR 32-63); 77% were female. 23/31 demonstrated inflammation of RCC cyst epithelium (n = 13), cyst wall (n = 20) or anterior pituitary (adenohypophysitis) (n = 12). 8 cases were not inflamed. Preoperative features included pituitary dysfunction (70%), headache (65%), visual disturbance (26%) and polyuria/polydipsia (7%). Six patients presented with features of apoplexy. Headache was more prevalent (92%) in patients with adenohypophysitis vs. those without (47%), p = 0.020, and present in all 11 cases where inflammation in the adenohypophysis was chronic. Pituitary dysfunction was not associated with inflammation overall (76% vs. 70% p = ns), nor specifically within the adenohypophysis (75 vs. 63% p = 0.69). Histological inflammation was associated with radiological loss of posterior bright spot (70% vs. 14% p = 0.024).

CONCLUSION

Headache but not pituitary dysfunction was associated with adenohypophyseal inflammation. A trend of increasing headache prevalence was seen with increasing degree of inflammatory infiltrate within RCC.

Insights Obtained from the Nontumorous Glandular Tissue in Patients with Endocrine Tumors

The pathology of neoplasia tends to focus on the tumor that requires characterization, grading, and staging. However, nontumorous tissue surrounding the lesion can also provide information, particularly about pathogenetic mechanisms. In endocrine tissues, this takes the form of precursor lesions that characterize several genetic predisposition syndromes. In addition, because of the unique functional aspects of endocrine neoplasia, the nontumorous tissue provides evidence of hormone excess, with hyperplasia and/or atrophy and other involutional changes allowing the pathologist to confirm both hormone function by the tumor and the effects of medical therapies. In this article, we review the various clinically relevant features that should be assessed and reported to enhance clinical management of patients with endocrine neoplasms. For example, in thyroid there may be inflammatory thyroiditis or goiter of various etiologies; there may be C-cell hyperplasia either as a preneoplastic lesion in patients with genetic predisposition to medullary thyroid carcinoma or as a reactive phenomenon. Drug-induced changes can be seen in thyroid and adrenal cortex. In neuroendocrine tissues, the nontumorous tissues may show precursor lesions such as endocrine cell hyperplasia/dysplasia; there may be related or unrelated hyperplastic or neoplastic lesions. Some tissues, such as pituitary corticotrophs and adrenal cortex, develop changes that reflect feedback suppression by hormone excess that can serve as biomarkers of tumor functionality and provide enhanced clinicopathologic correlates.

MR Imaging Appearance of Ruptured Rathke Cleft Cyst and Associated Bone Marrow Enhancement

Rathke cleft cysts are common cystic pituitary lesions seen on MR imaging. A subset of Rathke cleft cysts can rupture within the sella and are uncommon. The imaging appearance of a ruptured Rathke cleft cyst has been previously described with nonspecific imaging findings. We present 7 cases of ruptured Rathke cleft cysts and basisphenoid bone marrow enhancement below the sella that could be used to potentially distinguish a ruptured Rathke cleft cyst from other cystic lesions.

Panhypopituitarism Mimicking Acute Coronary Syndrome

A 59-year-old man suspected of having myocardial infarction with sinus bradycardia, a decreased blood pressure, and ST-change on an electrocardiogram was referred to our hospital's emergency department. Emergent coronary angiography revealed no significant findings. However, the patient experienced shock and required intensive care. Curiosity rose when his urination volume was not disturbed; we suspected hormonal abnormalities. A hormonal examination and imaging analysis revealed panhypopituitarism caused by a Rathke's cyst. Appropriate hormonal replacement therapy improved his symptoms and led to normalization of his electrocardiogram findings. Acute coronary syndrome (ACS) is a fatal disease; however, clinicians must not discount panhypopituitarism, as it may mimic ACS symptoms.

Xanthogranuloma of the sellar region: a systematic review

Knowledge of xanthogranuloma (XG) of the sellar region comes from short series or single cases. We performed a systematic review, using the PubMed, Web of Science, Embase, Scopus, eLibrary, and BIOSIS Preview databases, of all cases reported from 2000 to the present. We also describe one unreported patient treated in our institution. A search of the literature revealed that of 71 patients 50.7% were male and that mean age at diagnosis was 34.7 ± 19.2 years old. Median time from clinical onset until diagnosis was 7 (3-21) months. Hypopituitarism (70.4%), visual disorders (64.7%), headache (53.5%), and polyuria-polydipsia (28.2%) were the most common symptoms. On MRI, median tumor size was 20 (16-29) mm, while 71.8% were sellar/suprasellar and less frequently exclusively suprasellar (15.5%) or sellar (12.7%). On T1-weighted imaging, XG was hyperintense in 76.3% of patients, while it showed variable appearance on T2-weighted imaging. The tumor showed cystic features in 50.7%, gadolinium enhancement in 45.1%, and calcification in 22.5% of patients. All patients underwent surgery (77.4% transphenoidal approach and 18.3% craniotomy), with hypopituitarism (56.4%), diabetes insipidus (34.5%), and visual defects (7.3%) being the most common complications. Total/subtotal resection was achieved in 93.5%, while the tumor was partially removed in 6.6%. Median follow-up was 24 (6-55) months and no tumor recurrence or remnant growth was reported in 97.5% of cases. In conclusion, XG affects the younger population, manifested by hormonal deficit and mass effect symptoms. Surgery is safe and offers excellent outcomes, though hypopituitarism is frequent post-surgery. Tumor recurrence or remnant growth is rare and radiological surveillance is a good option for patients with remnant lesions.

Endoscopic Treatment of Rathke’s Cleft Cysts: The Case for Simple Fenestration

Background: Rathke’s cleft cysts (RCC) arise from the pars intermedia because of incomplete regression of the embryologic Rathke pouch. A subset of RCC becomes symptomatic causing headaches, visual and endocrinological disturbances such that surgical intervention is indicated. Several points in surgical management remain controversial including operative strategy (simple fenestration (SF) vs complete cyst wall resection (CWR)) as well as reconstructive techniques. Methods: A retrospective analysis was conducted of pathologically confirmed RCC operated on by endoscopic endonasal approach from 2006 to 2019. Pre-operative symptoms, imaging characteristics, operative strategy, symptom response, complications and recurrences were recorded. Results: Thirty-nine patients were identified. Thirty-three underwent SF and six underwent CWR. Worsening pituitary function was significantly increased with CWR (50%) compared to SF (3%) (p = 0.008). All patients underwent “closed” reconstruction with a post-operative CSF leak rate of 5% (3% SF vs 16% CWR, p = 0.287). Six (15%) recurrences necessitating surgery were reported. Recurrence rates stratified by surgical technique (18% SF vs 0% CWR, p = 0.564) were not found to be significantly different. Conclusions: The current series illustrates variability in the surgical management of RCCs. SF with closed reconstruction is a reasonable operative strategy for most symptomatic RCCs cases while CWR can be reserved for selected cases.

Xanthogranulomatous hypophysitis: A rare presentation in a young female patient

Hypophysitis is a rare inflammatory condition that may present both clinically and radiologically as a neoplastic lesion. Xanthogranulomas are rare intracranial lesions with controversial etiology. Here, we report a clinical case of histologically confirmed xanthogranulomatosis hypophysitis in a young female with type I diabetes mellitus and hypothyroidism.

Successful immunomodulatory treatment for recurrent xanthogranulomatous hypophysitis in an adolescent: illustrative case

BACKGROUND

Xanthomatous lesions of the pituitary have been linked to ruptured or hemorrhagic Rathke’s cleft cysts. Most cases are reported to resolve following radical resection. When recurrence does occur, there is no established treatment regimen. High-dose glucocorticoids have been reported to be beneficial in several published cases; however, their effects are often not sustained once therapy is discontinued.

OBSERVATIONS

The authors report the case of an adolescent male who developed recurrent xanthogranulomatous hypophysitis associated with a Rathke’s cleft cyst despite two surgical interventions. He was treated with a short course of dexamethasone followed by a maintenance course of celecoxib and mycophenolate mofetil. This regimen proved to be safe and well-tolerated, and it successfully prevented another recurrence of his xanthogranulomatous hypophysitis.

LESSONS

This case demonstrates a novel nonsurgical approach to the management of recurrent xanthogranulomatous hypophysitis. It suggests a potential application of a combined corticosteroid-sparing immunosuppressive and anti-inflammatory regimen in other cases of refractory xanthogranulomatous hypophysitis.

Preoperative differentiation of hypophysitis and pituitary adenomas using a novel clinicoradiologic scoring system

PURPOSE

Hypophysitis can clinically and radiologically mimic other nonfunctioning masses of the sella turcica, complicating preoperative diagnosis. While sellar masses may be treated surgically, hypophysitis is often treated medically, so differentiating between them facilitates optimal management. The objective of our study was to develop a scoring system for the preoperative diagnosis of hypophysitis.

METHODS

A thorough literature review identified published hypophysitis cases, which were compared to a retrospective group of non-functioning pituitary adenomas (NFA) from our institution. A preoperative hypophysitis scoring system was developed and internally validated.

RESULTS

Fifty-six pathologically confirmed hypophysitis cases were identified in the literature. After excluding individual cases with missing values, 18 hypophysitis cases were compared to an age- and sex-matched control group of 56 NFAs. Diabetes insipidus (DI) (p < 0.001), infundibular thickening (p < 0.001), absence of cavernous sinus invasion (CSI) (p < 0.001), relation to pregnancy (p = 0.002), and absence of visual symptoms (p = 0.007) were significantly associated with hypophysitis. Stepwise logistic regression identified DI and infundibular thickening as positive predictors of hypophysitis. CSI and visual symptoms were negative predictors. A 6-point hypophysitis-risk scoring system was derived: + 2 for DI, + 2 for absence of CSI, + 1 for infundibular thickening, + 1 for absence of visual symptoms. Scores ≥ 3 supported a diagnosis of hypophysitis (AUC 0.96, sensitivity 100%, specificity 75%). The scoring system identified 100% of hypophysitis cases at our institution with an estimated 24.7% false-positive rate.

CONCLUSIONS

The proposed scoring system may aid preoperative diagnosis of hypophysitis, preventing unnecessary surgery in these patients.

Hypophysitis

OBJECTIVE

Hypophysitis is considered a rare inflammatory disease of the pituitary gland. For a long time, primary autoimmune hypophysitis has stood out as the most relevant type of hypophysitis. However, with the advent of immunotherapy for the treatment of malignancies and identification of hypophysitis as an immune-related adverse event, hypophysitis has garnered increasing interest and recognition. Therefore, awareness, early recognition, and appropriate management are becoming important as the indication for immunomodulatory therapies broaden.

METHODS

In this review, we discuss the epidemiology, diagnosis, and treatment of hypophysitis with a focus on recent data and highlight subtypes of particular interest while recognizing the gaps in knowledge that remain.

RESULTS

Regardless of cause, symptoms and signs of hypophysitis may be related to mass effect (headache and visual disturbance) and hormonal disruption that warrant prompt evaluation. In the vast majority of cases, a diagnosis of hypophysitis can be made presumptively in the appropriate clinical context with radiologic findings consistent with hypophysitis and after the exclusion of other causes.

CONCLUSION

Although subtle differences currently exist in management and outcome expectations between primary and secondary causes of hypophysitis, universally, treatment is aimed at symptom management and hormonal replacement therapy.

Outcomes of Initial Management Strategies in Patients With Autoimmune Lymphocytic Hypophysitis: A Systematic Review and Meta-analysis

CONTEXT

Lymphocytic hypophysitis (LyHy) is characterized by inflammation of the pituitary and or neuroinfundibulum and is uncommon. Treatment options include observation, high-dose glucocorticoids (HD-GCs) or surgery. Optimal first-line management strategy, however, remains unknown.

OBJECTIVE

This work aimed to assess response to first-line treatment options (observation, HD-GCs, or surgery) of clinically relevant outcomes (symptomatic, hormonal, and radiographic improvement) among patients with LyHy.

METHODS

A systematic review was conducted in 6 databases through 2020. Meta-analysis was conducted when feasible using a random-effects model.

RESULTS

We included 33 studies reporting on 591 patients (423 women, 72%) with LyHy. Improvement/resolution of anterior pituitary dysfunction was highest when HD-GCs was first-line treatment. Surgery was associated with the greatest proportion of patients who had regression on imaging. Subgroup analysis comparing HD-GCs to observation showed the odds of anterior pituitary hormone recovery (OR 3.41; 95% CI, 1.68-6.94) or radiographic regression (OR 3.13; 95% CI, 1.54-6.36) were higher with HD-GCs, but so was the need for additional forms of treatment (OR 4.37; 95% CI, 1.70-11.22). No statistically significant difference was seen in recovery of diabetes insipidus (OR 0.9; 95% CI, 0.26-3.10). Certainty in these estimates was very low.

CONCLUSION

Observation and use of HD-GCs both are successful first-line management strategies in LyHy. Although use of HD-GCs was associated with increased recovery of anterior pituitary hormone deficit, it also was associated with greater likelihood of additional treatment after withdrawal. Optimal dosing and duration of HD-GCs remains unknown.

Xanthomatous Hypophysitis Secondary to a Ruptured Rathke's Cleft Cyst: A Case Report

Hypophysitis (HP) is a rare disease which develops secondary to chronic or acute inflammation of the pituitary gland and may cause symptoms related to pituitary dysfunction and mass compression. Lymphocytic HP is the most common subtype of primary HP, while xanthomatous HP (XHP) is considered the rarest form, with 35 reported cases, to date. A 35-year-old woman was initially admitted to a Gynecology clinic with a 2-year history of amenorrhea and headache. She was started on cabergoline 0.5 mg twice a week for macroprolactinoma. Due to persistent amenorrhea with low gonadotropins, she was referred to our Endocrinology clinic. Her pituitary function profile revealed panhypopituitarism and a 13×11×12 mm sized sellar mass with diffuse enhancement which sustained toward the infundibulum and dura was observed on the gadolinium-enhanced pituitary MRI. The patient underwent an endoscopic endonasal transsphenoidal approach for tumor resection and thick yellowish fluid draining from the lesion was observed. The histopathological diagnosis was reported as a rupture of an Rathke’s cleft cyst and an XHP. The surgery did not improve the symptoms/pituitary functions, however, headache recovered immediately after the first dose of high dose methylprednisolone treatment. The inflammatory process in a xanthomatous lesion may actually be a secondary response to mucous fluid content release from a ruptured cyst, thus recommended to classify XHP as secondary hypophysitis. Since the differentiation of XHP from other pituitary tumors may be challenging preoperatively, surgery is the major diagnostic tool and also, the most recommended therapeutic option.

Sellar Tumors

Sellar region lesions include a broad range of benign and malignant neoplastic as well as non-neoplastic entities, many of which are newly described or have recently revised nomenclature. In contrast to other intracranial sites, imaging features are relatively less specific, and the need for histopathological diagnosis is of paramount importance. This review will describe pituitary adenomas, inflammatory lesions, and tumors unique to the region (craniopharyngioma) as well as tumors which may occur in but are not exclusively localized to the sellar location (schwannoma, metastasis, etc.).

Histopathological findings in the landscape of IgG4-related pathology in patients with pituitary dysfunction: Review of six cases

IgG4-related hypophysitis (IgG4-RH) is increasingly being reported as an isolated entity or, less frequently, as a manifestation of a multiorgan IgG4-related disease (IgG4-RD), in which typical histopathology is a cornerstone for the diagnosis. We aimed to describe the histopathological changes in the surgical specimens from patients with clinical signs of pituitary disease that fulfilled the current diagnostic criteria for IgG4-RH. Histopathological features were correlated with clinical and radiological findings. Of 19 patients with pituitary dysfunction and inflammatory changes in the surgical pituitary specimen operated on during 2011-2019, we identified five patients with typical IgG4-related pathology (lymphoplasmacytic infiltration with more than 10 IgG4-positive plasma cells per one high power microscopic field, representing at least 40% of all plasma cells and at least focal storiform fibrosis). One patient with diabetes insipidus and pachymeningitis with IgG4-related changes in a biopsy from the dura was also included. Additional histopathological changes that typically are not part of the IgG4-RH were observed: Rathke's cleft cyst in four and granulomatous changes in two patients. One patient had an elevated serum IgG4 level and systemic manifestations that could be associated with the systemic IgG4-RD. Our findings indicate that pure IgG4-RH is uncommon. All patients with pituitary dysfunction, beyond typical IgG4-related pathology, had other pathological findings that could trigger the secondary IgG4-response. Both primary pathology and secondary IgG4-related features should be reported in patients with pituitary dysfunction because their co-occurrence may cause atypical clinical and imaging features, and unexpected response to surgical and pharmacological treatment. The current criteria for the diagnosis of IgG4-RH can lead to overdiagnosis of IgG4-RH if additional pathological changes are not taken into consideration. The classification criteria of IgG4-RD proposed by the American College of Rheumatology/European League Against Rheumatism could help classify patients more properly as IgG4-RH if applied to the pituitary gland.

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.

Xanthomatous Hypophysitis: A Case Report and Comprehensive Literature Review

PURPOSE

Xanthomatous hypophysitis (XHP) is an extremely rare form of primary hypophysitis for which there is a lack of clinical experience. A comprehensive understanding of its clinical characteristics, diagnosis and treatment is needed.

METHODS

Here, we report a case study and conduct a systematic review of XHP. Thirty-six cases were included, and their clinical manifestations, endocrine assessment, imaging features, treatment and follow-up data were collected and analyzed.

RESULTS

The mean age at diagnosis was 39.1 years, and females were predominant (75.0%). The most common symptom was headache (68.6%), and 66.7% of female patients presented menstrual disorders. The most common pituitary dysfunction was growth hormone (GH) deficiency. More than half of patients exhibited central diabetes insipidus (CDI). The majority of patients had an imaging presentation of a cystic lesion with peripheral enhancement. Pituitary stalk thickening was observed in half of the patients. Total lesion resection was achieved in 57.1% of cases. The recurrence rate after partial resection and biopsy was significantly higher than that after total lesion resection (57.1% vs. 0.0%, P = 0.0147). The most common pituitary hormone abnormalities to resolve after surgery were hyperprolactinemia (100.0%) and GH deficiency (91.7%). The typical pathological feature was inflammatory infiltration of foamy histiocytes, which showed positivity for CD68.

CONCLUSION

Diagnosis of XHP is difficult when relying on clinical symptoms and imaging features. Therefore, surgical histopathology is necessary. Based on the available evidence, total lesion resection is recommended for treatment. However, the long-term prognosis for this rare disease remains unclear.

Recurring Primary Xanthomatous Hypophysitis Behaving Like Pituitary Adenoma: Additional Case and Literature Review

BACKGROUND

Xanthomatous hypophysitis (XH) is the rarest histologic type of primary hypophysitis. It is nonlymphocytic and characterized by an infiltration of the pituitary gland by lipid-laden histiocytes and macrophages. The clinical and radiologic features overlap heavily with pituitary adenomas and are prone to misdiagnosis. We describe a rare case of XH recurrence at 1 year, treated surgically. Moreover, we provide an updated review of the literature to further elucidate useful management and detection strategies.

CASE DESCRIPTION

A 45-year-old woman presented with a history of menstrual irregularity for 9 months, amenorrhea, galactorrhea, and headache for 2 months duration. Preoperative endocrinologic studies showed increased prolactin levels. Magnetic resonance imaging of the sella showed a cystic lesion with suprasellar extension suggestive of a pituitary adenoma. The patient underwent transsphenoidal resection, showing a thick yellowish colloidal material. Histopathology showed necrotic tissue with no definitive diagnosis and no identified microorganisms. At 2 months after surgery, prolactin levels and menstrual cycle normalized. At 1 year after surgery, her menstrual cycle again became irregular. Repeat magnetic resonance imaging showed a recurrent mass and a second transsphenoidal resection was undertaken. Repeat histopathology was consistent with XH. The patient is 9 years postoperative and is doing well without evidence of recurrence.

CONCLUSIONS

XH presents similarly to nonfunctional adenomas and diagnosis remains difficult without surgical pathology, requiring meticulous immunohistochemistry to prevent misdiagnosis. Thus, XH should be considered as a rare cause in the differential of disease of the sellar region. Management can parallel that of pituitary neoplasm, with a focus on radiosurgery, re-resection, and high-dose steroids.

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.

Comprehensive Evaluation of Rare Pituitary Lesions: A Single Tertiary Care Pituitary Center Experience and Review of the Literature

The 2017 World Health Organization classification of central nervous system and endocrine tumors have introduced significant changes in the diagnostic criteria for pituitary lesions. The aim of our paper is to describe the epidemiological, clinico-pathological, and radiological features of a single consecutive institutional surgical series of rare pituitary lesions, using these new criteria. Of the 316 endoscopic endonasal trans-sphenoidal approaches performed for pituitary lesions between 2010 and 2018, 15 rare lesions were encountered. These included metastases, pituitary carcinomas, pituicytomas, granular cell tumor, primary pituitary lymphomas, germinoma, mixed gangliocytoma-adenoma, hypophysitis, and pituitary hyperplasia. Their clinical, radiological, and pathological features are herewith presented along with a literature review that enabled us to propose an algorithm to facilitate a diagnosis for rare pituitary lesions.

Hypophysitis in the era of immune checkpoint inhibitors and immunoglobulin G4-related disease

INTRODUCTION

Hypophysitis is a rare disorder, defined as inflammation of the pituitary gland that may result in pituitary enlargement and varying anterior and posterior pituitary hormonal deficits. It involves different histopathological subtypes and variable etiologies, with considerable overlap between classification systems. Histopathology is the gold standard diagnostic approach.

AREAS COVERED

In this article, we will review the major histopathological subtypes of hypophysitis with a special focus on immunoglobulin G4 (IgG4)-related hypophysitis and immune checkpoint inhibitor-induced hypophysitis, given their recent appearance and increasing incidence. We will summarize the similarities and differences between the different subtypes as it relates to epidemiology, pathogenesis, presentation, diagnosis, and management.

EXPERT OPINION

Hypophysitis is a heterogeneous and wide term used to describe different, possibly distinct diseases often with poorly understood pathogenesis. It involves a wide range of subtypes with certain differences in incidence rates, pathogenesis, and management. Management usually focuses on relieving the mass effect symptoms and replacing the deficient pituitary hormones. Spontaneous recovery is possible but recurrence is not uncommon.

High prevalence of adrenal insufficiency at diagnosis and headache recovery in surgically resected Rathke's cleft cysts-a large retrospective single center study

BACKGROUND

Rathke's cleft cysts (RCC) are lesions that arise from Rathke's pouch. Though frequently incidental, resulting symptoms in a minority of cases are indicators for surgical resection, which may prove beneficial.

OBJECTIVE

To characterize a cohort of surgically-resected RCC cases at Oregon Health & Science University; tabulate associated hormonal imbalances and symptoms, possible symptom reversal with surgery, determine recurrence risk; identify predictors of recurrence and headache improvement.

METHOD

Electronic records of all RCC resected cases (from 2006-2016; 11 years) were retrospectively reviewed. Patients had been evaluated by one neuroendocrinologist using a uniform protocol.

RESULTS

A pathological RCC diagnosis was established in 73 of 814 (9%) surgical pituitary cases. The RCC cohort was 77% (n = 56/73) female, mean age was 39.5 ± 14.9 years at first surgery, and at presentation headache was reported in 88% and visual defects/diplopia in 18% of patients. Initial RCC maximum diameter was 1.3 ± 0.7 cm. The most frequent hormonal deficit was cortisol; 24% of patients had a new adrenal insufficiency (AI) diagnosis, however, 36% also had AI at 3 months post-operatively. Mean follow up was 4.0 ± 4.5 years. Two-thirds of patients (41/62) had headache improvement 3 months post-operatively. Post-operative imaging revealed no residual cyst in 58% (38/65). In those patients with no residual RCC, 29% had recurrence and 71% had long lasting cure. From the 42% (27/65) of patients with residual cyst on post-operative imaging; 59% (16/27) remained stable, 26% (7/27) progressed and 15% (4/27) regressed.

CONCLUSION

Symptomatic RCC present mostly in women, with a high proportion reporting headaches. Prevalence of AI at diagnosis is high. Surgery may not achieve adrenal axis recovery, but renders a high percentage of headache improvement. Approximately 25% of RCC will recur by 4 years postoperatively. Clinicians should cautiously screen patients with symptomatic RCC, regardless of lesion size for AI.

Primary hypophysitis and other autoimmune disorders of the sellar and suprasellar regions

The pituitary gland and the hypothalamus can be affected by autoimmune-mediated structural and functional disruption. These autoimmune-mediated diseases occur more commonly in females and are often found during pregnancy or in the post-partum period. Autoimmune diseases can either affect parts of the pituitary or hypothalamus, or can involve both sellar and suprasellar structures. Most of these cases comprise primary hypophysitis (PRH). Over the years, there has been a tremendous increase in the number of reported PRH cases and related disorders, including hypophysitis induced by immune checkpoint inhibitors. With this increasing data, more light is being shed on the spectrum of clinical presentations, biochemical and imaging abnormalities of these disorders. Regardless, these disorders are still relatively rare. The clinical presentation can vary vastly, based on the type of pituitary cell or the area of the suprasellar region affected. The severity can range from clinically silent disease to progressive and rapid deterioration and death, likely due to unrecognized central adrenal insufficiency. Although biopsy remains a gold standard for diagnosing these disorders, the current standard of practice is biochemical assessment for hormonal deficiencies and imaging studies. In several instances, these disorders spontaneously resolve, but medical or surgical intervention might be necessary to treat symptomatic disease. Due to the subtlety and a vast spectrum of clinical manifestations which could often be asymptomatic, and the rarity of the occurrence of these diseases in clinical practice, the diagnosis can be easily missed which could potentially lead to substantial morbidity or mortality. Therefore, it is crucial to have a strong clinical suspicion and pursue timely biochemical and imaging studies to initiate prompt treatment. In this article, we review the various autoimmune conditions that affect the sellar and suprasellar structures, their diagnostic approach and management of these disorders.

Xanthomatous hypophysitis causing hypogonadotropic hypogonadism resulting in delayed presentation of slipped capital femoral epiphysis

An 18-year-old man who underwent bilateral pinning of his hip joints after a left unstable Slipped Capital Femoral Epiphysis (right pinned prophylactically) was noted to have delayed secondary sexual characteristics and post-operative diabetes insipidus. The patient also described a history of fatigue, headache and polydipsia for the past 4 years. Endocrine investigations revealed reduced androgen levels, hypocortisolism, a borderline normal Serum ACE and secondary hypothyroidism. Magnetic Resonance Imaging of the pituitary gland identified an enhancing mass and a thickened stalk which trans-nasal endoscopic biopsy found to be necrotic with pus. Histology confirmed a diagnosis of Xanthomatous Hypophysitis, an inflammatory condition likely related to a partial rupture of a Rathke cleft cyst. The patient was subsequently commenced on Androgen, Thyroxine, Desmopressin and Hydrocortisone therapy with on-going endocrine follow-up. Although endocrine dysfunction & hypogonadism has been recognised to be a risk factor for SCFE at an atypically older age, due to reduced androgen levels leading to a weakened physeal plate, this is the first known case of a Xanthomatous Hypophysitis resulting in pituitary dysfunction and eventual SCFE. This case highlights that an increased range of pituitary disorders should be considered in late presentations of SCFE; and vice versa the risk of SCFE should be considered in patients with prolonged hypogonadotropic hypogonadism.

What's new in pituitary pathology?

The increasing recognition of pituitary disorders and their impact on quality of life and longevity has made understanding of this small gland a subject of paramount importance. Pituitary pathology has seen many significant studies that indicate progress in identification and classification of pituitary lesions, as well as improved management strategies for patients. In this review, we outline six major areas of advances: (i) changes in terminology from 'adenoma' to 'pituitary neuroendocrine tumour'; (ii) reclassification of hormone-negative tumours based on transcription factor expression that defines lineage; (iii) updates in new pathogenetic mechanisms, including those that underlie rare lesions such as X-LAG and pituitary blastoma; (iv) clarification of hypophysitis due to immunotherapy, xanthomatous hypophysitis due to rupture of a Rathke's cleft cyst and IgG4 disease as the cause of inflammatory pseudotumour; (v) the consolidation of pituicytoma variants, including spindle cell oncocytoma and granular cell tumour based on thyroid transcription factor-1 (TTF-1) reactivity; and (vi) the pathogenetic mechanisms that distinguish papillary from adamantinomatous craniopharyngioma. The remaining challenge is clarification of the pathogenetic mechanisms underlying the development of many of these disorders.

Immunohistochemical Biomarkers in Pituitary Pathology

Pituitary pathology is one area of endocrine pathology that is highly dependent on immunohistochemistry. There is a wide range of disorders that occur in and around the sella turcica, and the distinction of tumor-like lesions from neoplasms requires careful evaluation. The diagnosis, prognosis, and predictive features of neoplasms in the sellar region are all dependent on the application and interpretation of biomarkers of cell differentiation, hormonal activity, subcellular morphology, and proliferation. As in hematopathology, the number of biomarkers has increased dramatically and continues to increase. Fortunately, some of the biomarkers provide information that was initially dependent on electron microscopy; therefore, the need for this additional technology has been reduced to only rare unusual tumors. In this review, we provide a simple approach to understanding the importance of the various biomarkers that are used to ensure the correct diagnosis and provide the treating clinicians with tools to guide appropriate patient management and surveillance.